A detailed study on a small scale of the effect of phosphatization on the chemistry of marine cobalt-rich ferromanganese crusts supplies useful information for the evaluation and comprehensive utilization of crust min...A detailed study on a small scale of the effect of phosphatization on the chemistry of marine cobalt-rich ferromanganese crusts supplies useful information for the evaluation and comprehensive utilization of crust mineral resources. Sub-samples from top to bottom of a 10-cm thick sample from the NW Pacific Magellan seamount were taken at 5 mm intervals. The concentration profiles of ore-forming and rare earth elements show that obvious differences exist between young unphosphatized crusts and old phosphatized crusts. In the old crusts Fe, Mn, Si, Al, Zn, Mg, Co, Ni and Cu elements are depleted and Ca, P, Sr, Ba and Pb elements are enriched. The order of depletion is Co > Ni > Mg > Al > Mn > Si> Cu > Zn > Fe, while the order of enrichment is P > Ca > Ba > Pb > Sr. The phosphate mineral controls the concentration variation of the ore-forming elements in crusts and causes loss of the main ore-forming elements such as Co and Ni. The phosphatization also affects the abundance of REEs in the crusts. REEs are more abundant and the content of Ce in old crusts is higher than that in young crusts, however, the pattern of REEs and their fractionation characteristics in new and old crusts are not fundamentally changed. A Y-positive anomaly in old crusts has no relationship to the phosphatization.展开更多
In the present paper, iodine （I）, iron （Fe）, manganese （Mn）, cobalt （Co）, phosphorus （P） and calcium （Ca） contents in three ferromanganese crusts from the Pacific Ocean are measured by spectrophotometric m...In the present paper, iodine （I）, iron （Fe）, manganese （Mn）, cobalt （Co）, phosphorus （P） and calcium （Ca） contents in three ferromanganese crusts from the Pacific Ocean are measured by spectrophotometric method and inductively coupled plasma atomic emission spectrometers （ICP-AES） to investigate the contents and distribution of iodine in ferromanganese crusts. The results show that iodine contents in three crusts vary between 27.1 and 836 mg/kg, with an average of 172 mg/kg, and the profile of iodine in the three crusts all exhibits a two-stage distribution zone： a young non-phosphatized zone and an old phosphatized zone that is rich in I, P and Ca. The iodine content ratios of old to young zone in MP5D44, CXD62-1 and CXD08-1 are 2.3, 3.4 and 13.7, respectively. The boundary depths of two-stage zone in MP5D44, CXD62-1 and CXD08-1 locate at 4.0 cm, 2.5 cm and 3.75 cm, respectively, and the time of iodine mutation in three crusts ranges from 17-37 Ma derived from 129I dating and Co empirical formula, which is consistent with the times of Cenozoic phosphatization events. The present study shows that the intensity of phosphatization is the main responsible for the distribution pattern of iodine in the crusts on the basis of the correlation analysis. Consequently, iodine is a sensitive indicator for phosphatization.展开更多
Biomineralization may have an extremely long evolutionary history since the Paleoarchean, while the widespread biomineralization among metazoan lineages started at the earliest Cambrian. However, the primary mineralog...Biomineralization may have an extremely long evolutionary history since the Paleoarchean, while the widespread biomineralization among metazoan lineages started at the earliest Cambrian. However, the primary mineralogy of Anabarites shell remains controversial. Optical microscopic observations combined with the Back-Scattered Electron（BSE） and Energy-Dispersive X-ray Spectroscopy（EDS） analyses are used to study the shell of the fossil Anabarites from the Kuanchuanpu fauna in southern Shaanxi Province in China, which is correlated to the Cambrian Fortunian Stage. The EDS analysis shows that the phosphorus-rich layer closely adjacent to the calcified layer exhibits a Ca： P： C ratio compositionally similar to the mineral fluorapatite（Ca_5（PO_4,CO_3）_3（F,CO_3）. The result that the calcified layer and the phosphorus-rich layer have different chemical compositions is consistent with the optical observation that there is an obvious gap between these two layers and the phosphorus-rich layer can extend to the phosphatic material inside of the tube, suggesting the phosphorus-rich layer doesn＇t belong to the original shell. We suggest that the phosphorous-rich layer is diagenetic in origin, precipitated as a result of phosphorus release during the decay of organic matter by microbes. Considering the outermost shell layer（OMS, biologically controlled carbonate shell layer） should display different isotopic information from the carbonate matrix（i.e., OMS is ^（12）C concentrated due to the biogenic organic matter template is readily rich in ^（12）C）, Nano SIMS was used to map ion distributions of C and N in the shell of Anabarites and matrix. However, ion images show that the concentration differences of ^（12）C, ^（13）C and ^（26）CN among the OMS and the matrix are unclear, while ^（12）C and ^（26）CN are supposed to be enriched in the OMS. Therefore, the minor isotopic differences between the shell and the matrix is hard to be detected by Nano SIMS, at least in our sample, probably due to alteration of the ^（12）C-rich characteristic of the Anabarites OMS during the late diagenesis.展开更多
It was ascertained that when a RE element was added in bath,the sample was improved on the anti-corrosion power of the coating because of the increasing of covering rate of formless crystal Zn2Fe(PO4) 2·4H2O(mark...It was ascertained that when a RE element was added in bath,the sample was improved on the anti-corrosion power of the coating because of the increasing of covering rate of formless crystal Zn2Fe(PO4) 2·4H2O(marked P) crystals and the ratio of P/(P+H) (H was the mark of Zn3(PO4) 2 crystal) in the coating,combination of which with components parsing by EDS indicated that the sequence of contribution elements P and Zn to erosion resistance of coatings was P】Zn. And the correlative mechanism was discussed,which made it clear that owing to the particularity of the outer-shell electron structure and larger ionic radius,RE was so easy to be polarized and metamorphosed itself that it adsorbed lightly on the basic body to pose gels. They efficiently reduced the activation energy which was required for formation of a new solid phase of phosphates and made it also possible to engender effectively active nucleation regions of cathode and anode under low temperature phosphating condition,which was propitious to formation,densification and uniformization of the phosphate crystal nucleus and growth of the crystallite and coating buildup. Thus it could be seen that REN played the role of surface regulator and accelerant,which speeded up the phosphating,as well as bids amount of porosity of the coating fall to improve the corrosion resistance of the coating.展开更多
Oceanic phosphatization events episodically precipitate carbonate fluorapatite(CFA),inducing phosphatization of ferromanganese crusts and significantly influencing rare earth elements plus yttrium(REY)and associated m...Oceanic phosphatization events episodically precipitate carbonate fluorapatite(CFA),inducing phosphatization of ferromanganese crusts and significantly influencing rare earth elements plus yttrium(REY)and associated metal concentrations.Western Pacific ferromanganese crusts archive multiple phosphatization events,yet the absence of accurate chronological constraints hindered detailed investigations into the mechanisms of REY redistribution during distinct phosphatization episodes.Building upon previously established phosphatization events through CFA U-Pb geochronology,this study investigates three ferromanganese crusts from different water depths on Ita Mai Tai Guyot(Western Pacific)to evaluate the impacts of phosphatization on REYenrichment.Results show that all three hydrogenetic crusts experienced phosphatization,with phosphatized layers exhibiting higher average REY concentrations(2090,1885,and 1854 ppm)than non-phosphatized layers(1413,1174,and 1519 ppm),indicating that phosphatization enhances REYenrichment.However,when the crusts are precisely divided based on phosphatization episodes,one phosphatized layer(1293 ppm)exhibits lower REY concentrations than the unphosphatized layer(1413 ppm).This is attributed to a dilution effect from the precipitation of REY-poor authigenic CFA;the apatite within this specific layer contains only 602 ppm REY,a value lower than that of the unphosphatized crust.Concurrently,“REY-rich”veinlike CFA(2703 ppm)is associated with slow depositional processes,indicating its potential to increase the REY content of crusts.Therefore,this study reveals the dual role of phosphatization on REY enrichment.It can either promote enrichment by enhancing REY adsorption onto iron-manganese oxides and by forming REY-rich CFA,or cause dilution through the precipitation of REY-poor CFA.The net effect is ultimately controlled by a combination of environmental factors,including sedimentation rate and water depth,revealing the complex mechanisms of REY in phosphatized ferromanganese crusts.展开更多
Small shelly fossils(SSFs)have long been recognized as important to the studies of both metazoan evolution and the onset of biomineralization during the Cambrian radiation.The marked decline in the occurrence,diversit...Small shelly fossils(SSFs)have long been recognized as important to the studies of both metazoan evolution and the onset of biomineralization during the Cambrian radiation.The marked decline in the occurrence,diversity and abundance of SSFs in the middle to late Cambrian,when compared with the early Cambrian,has often been regarded as a result of the closure of a phosphatization window.Despite this,there have been numerous and consistent reports of SSFs from the middle Cambrian and younger deposits.To identify possible factors influencing SSF preservation,five microfacies including bioclastic limestone,flat-pebble conglomerates with bioclasts,hummocky cross-stratified grainstone with bioclasts,bioclastic grainstone in hardgrounds and glauconite bioclastic wackstone-packstone,from Cambrian Series 2 to Miaolingian in North China are compared to assess how differences in lithology impact the preservation potential of SSFs.Our results,based on 35,161 SSF specimens from deposits across six sections,suggest that there are still abundant and diverse SSFs in the middle Cambrian of North China preserved in ways not exclusively reliant on the presence of phosphate and that SSF preservation can be linked to the differences in microfacies in the early to middle Cambrian of North China.展开更多
Guided bone regeneration in the alveolar bone relies on the colonization and differentiation of immune cells within the defect area.The absence of osteoinductive and osteoimmune properties of currently available scaff...Guided bone regeneration in the alveolar bone relies on the colonization and differentiation of immune cells within the defect area.The absence of osteoinductive and osteoimmune properties of currently available scaffolds hinders to achieve optimal repair outcomes in clinical settings.Thus,we aimed to enhance the bone repair ability of polycaprolactone(PCL)scaffolds by incorporating osteoinductive amorphous calcium phosphate(ACP)with immune-regulating zinc ions(ACP(Zn),ACZP),to create a favorable immunomodulatory microenvironment.After one day of co-culture with PCL-ACZP,the spreading area of macrophage cells was significantly higher than that from the original PCL scaffold.Additionally,over 32.1%of macrophages exhibited M2 polarization within three days of co-culture.The PCLACZP/macrophage-conditioned medium significantly boosted osteogenic gene expression in MC3T3-E1 cells.After eight weeks of implantation in a rat femoral condyle defect,the BV/TV from the PCL-ACZP group reached 32.9%,1.4 times of that from the PCL group.Furthermore,the PCL-ACZP-GelMA biphasic module as prepared successfully achieved complete regeneration of three-walled alveolar bone defects in rabbits,resulting in arch-shaped alveolar bone repair and providing greater convenience in the clinical settings.This study showcased the effectiveness of PCL-ACZP-GelMA biphasic module as bioactive scaffolds in the morphological restoration of alveolar bone.展开更多
The soaring demand for smart portable electronics and electric vehicles is propelling the advancements in high-energy–density lithium-ion batteries.Lithium manganese iron phosphate(LiMn_(x)Fe_(1-x)PO_(4))has garnered...The soaring demand for smart portable electronics and electric vehicles is propelling the advancements in high-energy–density lithium-ion batteries.Lithium manganese iron phosphate(LiMn_(x)Fe_(1-x)PO_(4))has garnered significant attention as a promising positive electrode material for lithium-ion batteries due to its advantages of low cost,high safety,long cycle life,high voltage,good high-temperature performance,and high energy density.Although LiMn_(x)Fe_(1-x)PO_(4)has made significant breakthroughs in the past few decades,there are still facing great challenges in poor electronic conductivity and Li-ion diffusion,manganese dissolution affecting battery cycling performance,as well as low tap density.This review systematically summarizes the reaction mechanisms,various synthesis methods,and electrochemical properties of LiMn_(x)Fe_(1-x)PO_(4)to analyze reaction processes accurately and guide material preparation.Later,the main challenges currently faced are concluded,and the corresponding various modification strategies are discussed to enhance the reaction kinetics and electrochemical performance of LiMn_(x)Fe_(1-x)PO_(4),including multi-scale particle regulation,heteroatom doping,surface coating,as well as microscopic morphology design.Finally,in view of the current research challenges faced by intrinsic reaction processes,kinetics,and energy storage applications,the promising research directions are anticipated.More importantly,it is expected to provide key insights into the development of high-performance and stable LiMn_(x)Fe_(1-x)PO_(4)materials,to achieve practical energy storage requirements.展开更多
In this study,a phosphate-based conversion coating(PCC)was applied as a precursor before forming silicate-fluoride(SiF)and silicate-phosphate-fluoride(SiPF)based flash-plasma electrolytic oxidation(Flash-PEO)coatings ...In this study,a phosphate-based conversion coating(PCC)was applied as a precursor before forming silicate-fluoride(SiF)and silicate-phosphate-fluoride(SiPF)based flash-plasma electrolytic oxidation(Flash-PEO)coatings on AZ31B magnesium alloy.The main novelty is the successful incorporation of calcium,zinc,manganese and phosphate species into the Flash-PEO coatings via a precursor layer rather than using the electrolyte.The precursor also led to longer lasting and more intense discharges during the PEO process,resulting in increased pore size.Corrosion studies revealed similar short-term performance for all coatings,with impedance modulus at low frequencies above 10^(7)Ωcm^(2),and slightly better performance for the SiPF-based coating.Nonetheless,the enlarged pores in the PEO coatings functionalized with the PCC precursor compromised the effectiveness of self-healing mechanisms by creating diffusion pathways for corrosive species,leading to earlier failure.These phenomena were effectively monitored by recording the open circuit potential during immersion in 0.5 wt.%NaCl solution.In summary,this study demonstrates that conversion coatings are a viable option for the functionalization of PEO coatings on magnesium alloys,as they allow for the incorporation of cationic and other species.However,it is crucial to maintain a small pore size to facilitate effective blockage through self-healing mechanisms.展开更多
Whilst phosphorus(P)in soil is considered to be abundant,the portion available for plant uptake constitutes less than 1%of the overall P present.To enhance crop productivity,the utilization of mineral P fertilizers ha...Whilst phosphorus(P)in soil is considered to be abundant,the portion available for plant uptake constitutes less than 1%of the overall P present.To enhance crop productivity,the utilization of mineral P fertilizers has become pervasive in agriculture.Nonetheless,the escalating prices of chemical fertilizers,coupled with new European regulations prohibiting the use of P fertilizers containing cadmium,have highlighted the urgency to identify environmentally friendly products and practices for P fertilization in agricultural soils.This comprehensive review delves into the current landscape of P fertilization from agricultural,political,and economic standpoints.We recognize the potential of microbes in mobilizing P,but emphasize the necessity for more robust research to establish their effectiveness in promoting plant P uptake under real-world conditions.Additionally,we explore the role of agricultural conservation practices,such as optimal tillage,diversified cropping systems,and increased organic carbon input,in conserving P.Furthermore,this review contemplates forthcoming innovations in research.These innovations encompass the development of enhanced formulations for biofertilizers and the undertaking of more comprehensive studies within the realm of conservation agriculture.All these endeavors collectively hold the potential to augment P accessibility to plants in a sustainable manner,thereby advancing agricultural sustainability and productivity.展开更多
The interaction mechanism between eggshell calcium and endogenous silica in biomass during biochar modification,and its impact on phosphate adsorption performance and slow-release fertilizer characteristics,remains un...The interaction mechanism between eggshell calcium and endogenous silica in biomass during biochar modification,and its impact on phosphate adsorption performance and slow-release fertilizer characteristics,remains unexplored.This study investigates that high silica content in biomass(>6%)inhibits the decomposition of CaCO_(3)in eggshells during pyrolysis,reducing the formation of active calcium species(CaO and Ca(OH)_(2)),while moderate silica levels(4%-5%)promote the formation of CaSiO_(3),enhancing phosphorus adsorption without hindering Ca^(2+)activation.Adsorption studies reveal that the precipitation of Ca_(5)(PO_(4))_(3)(OH)resulting from the combination of CaO and Ca(OH)_(2)with phosphate is the primary and effective form for phosphorus removal in calcium-modified adsorbents,accompanied by Ca_(3)(PO_(4))_(2)·2H_(2)O precipitation formed by CaSi O_(3).Eggshell calcium-modified corn straw biochar(ECS)exhibited the highest adsorption capacity,reaching 123.3 mg/g,outperforming materials in previous studies.ECS also demonstrated excellent pH adaptability and selective phosphate removal.As a biochar-based phosphorus fertilizer,ECS-P exhibits high phosphorus extractability in formic acid(93.92%)but low water solubility(0.62%),with phosphorus release during the seven-day intermittent leaching experiment remaining between 0.53 to 0.875 mg/L.These results confirm its potential as a phosphorus cycling fertilizer.This study provides fundamental insights into optimizing biomass selection based on silica content for calcium modification,offering an efficient strategy for both phosphate recovery and slow-release fertilizer development.展开更多
The efficient recycling of spent lithium iron phosphate(LiFePO_(4),also referred to as LFP)should convert Fe(Ⅱ)to Fe(Ⅲ),which is key to the extraction of Li and separation of Fe and is not well understood.Herein,we ...The efficient recycling of spent lithium iron phosphate(LiFePO_(4),also referred to as LFP)should convert Fe(Ⅱ)to Fe(Ⅲ),which is key to the extraction of Li and separation of Fe and is not well understood.Herein,we systematically study the oxidation of LiFePO_(4)in the air and in the solution containing oxidants such as H_(2)O_(2)and the effect of oxidation on the leaching behaviors of LFP.In the air,O_(2)breaks down the LFP olivine structure at 550℃for 1 h by oxidizing Fe(Ⅱ)to Fe(Ⅲ)in terms of converting LFP to Li_(3)Fe_(2)(PO_(4))_(3)and Fe_(2)O_(3).After that,Li is leached in 0.5 M sulfuric acid solution and is further recycled as Li_(3)PO_(4)with a Li recovery efficiency of 97.48%.Meanwhile,Fe is recovered as FePO_(4)and Fe_(2)O_(3).Compared with H_(2)SO_(4)-H_(2)O_(2),the air oxidation saves H_(2)O_(2)but increases the leaching efficiency of Fe and H_(2)SO_(4)consumption.The discrepancy of Fe leaching efficiency can be attributed to the different leaching mechanisms involving the solid-to-solid and solid-to-liquid-to-solid conversions.Furthermore,the results of the Everbatt model analysis show that the air roasting-H_(2)SO_(4)leaching method has low emission and potentially high income,which is simple and safe.Overall,this work will deepen the understanding of acid leaching of LFP and favorably stimulate the maturation of the LFP recycling technique.展开更多
Pure Mg boasting a relatively small corrosion rate is a potential biodegradable metal material for implants.However,its degradation behavior in the complex physiological environment is still a lack of understanding.In...Pure Mg boasting a relatively small corrosion rate is a potential biodegradable metal material for implants.However,its degradation behavior in the complex physiological environment is still a lack of understanding.In this work,we investigated the effect of corrosion product film layers on the degradation behavior of pure Mg in physiological environments.Pure Mg shows a faster corrosion rate in simulated body fluid(SBF)compared to NaCl solution.Hydrogen evolution experiments indicate that the degradation rate of pure Mg in SBF decreases rapidly within the first 12 h but stabilizes afterward.The rapid deposition of low-solubility calcium phosphate on the pure Mg in SBF provides protection to the substrate,resulting in a gradual decrease in the degradation rates.Consequently,the corrosion product film of pure Mg formed in SBF exhibits a layered structure,with the upper layer consisting of dense Ca_(3)(PO_(4))_(2)/Mg_(3)(PO_(4))_(2) and the lower layer consisting of Mg(OH)_(2)/MgO.Electrochemical impedance spectroscopy(EIS)shows that the resistance of the corrosion product film increases over time,indicating gradual strengthening of the corrosion resistance.The 4-week degradation results in the femoral marrow cavity of mice are consistent with the result in SBF in vitro.展开更多
Developing high-efficient and low-loading Pt based catalyst is significant for the electrocatalytic p Huniversal hydrogen evolution reaction(HER). Herein, the molybdenum carbide nanoparticles supported on the polyhedr...Developing high-efficient and low-loading Pt based catalyst is significant for the electrocatalytic p Huniversal hydrogen evolution reaction(HER). Herein, the molybdenum carbide nanoparticles supported on the polyhedral N-doped carbon nanotube skeleton(Mo C/NCT) composite has been synthesized by a pyrolysis of polyacid organo-metallic phosphate framework precursor. Then, only 2.15 wt% Pt are loaded on the Mo C/NCT to form Pt-Mo C/NCT catalyst, which performs superior HER activity and stability in entire p H range. Specially, the overpotentials of 22 and 74 m V are respectively attained at 10 m A/cm^(2) in1.0 mol/L KOH and 0.5 mol/L H_(2)SO_(4) electrolytes, approaching or even exceeding commercial Pt/C. More importantly, it can be used as excellent catalyst for efficient hydrogen production at 0–14 p H range. Density functional theory(DFT) calculations demonstrate that the interaction between Mo C and Pt leads to the electron redistribution at the corresponding interfaces and the downward shift of the d-band centers, thus optimizing H*adsorption and desorption for promoting the HER activity. Besides, the unique three-dimensional network structure is conductive to the transmission of mass and electrons. In the application of both alkaline and acidic electrolysers, only 1.52 V voltage of solar panel can drive a hydrogen production current density of 10 m A/cm^(2).展开更多
Potassium hydroxide(KOH)was introduced into the molybdenite roasting process to convert molybdenum(Mo)and sulfur(S)into water-soluble potassium molybdate(K_(2)MoO_(4))and potassium sulfate(K_(2)SO_(4)).Roasting with a...Potassium hydroxide(KOH)was introduced into the molybdenite roasting process to convert molybdenum(Mo)and sulfur(S)into water-soluble potassium molybdate(K_(2)MoO_(4))and potassium sulfate(K_(2)SO_(4)).Roasting with a 1.8-fold excess of KOH at 400℃ for 3 h enabled the leaching of over 99%of Mo from the molybdenum calcine using water.A precipitation method involving potassium–magnesium(K-Mg)salts was proposed for impurity removal.Under the conditions of pH 11,30℃,excess coefficient of 1.7 for Mg salts,and a duration of 1 h,98.37%of phosphorus(P)was removed from the K_(2)MoO_(4) solution.With post-purification,over 99%of Mo crystallized upon adjustment of pH to 1.Subsequently,S and K were recovered as K_(2)SO_(4) fertilizer from the crystalline mother liquor.An environmentally sustainable approach was proposed to conduct molybdenite production and ensure the efficient recovery of both Mo and S.展开更多
Silicone rubber(SR)exhibits superior breathability and high-temperature resistance.However,SR is prone to degradation under extreme heat or combustion,limiting its effectiveness in mitigating secondary hazards.In this...Silicone rubber(SR)exhibits superior breathability and high-temperature resistance.However,SR is prone to degradation under extreme heat or combustion,limiting its effectiveness in mitigating secondary hazards.In this study,phosphate glass powder was used to calcinate zinc borate,lanthanum oxide,and cerium oxide.Methylphenyl polysiloxane was then grafted onto the surface of the glass powder,resulting in the modified pow-ders designated as Methylphenyl polysiloxane-grafted zinc borate-modified phosphate glass powder(GF-ZnBM),Methylphenyl polysiloxane-grafted lanthanum oxide-modified phosphate glass powder(GF-LaM),and Methylphenyl polysiloxane-grafted cerium oxide-modified phosphate glass powder(GF-CeM).The modified powders were sub-sequently incorporated into silicone rubber composites to enhance the ceramicization capability of silicone rubber at high temperatures.Specifically,GF-CeM and GF-LaM significantly increased the limiting oxygen index(LOI)to 33%and reduced the tendency for combustion propagation.Additionally,GF-CeM notably contributed to enhancing ceramicization strength.The presence of cerium oxide helps in the melting of the glass powder and enhances its adhesion to the silicone rubber matrix.SR/ZnB-GF exhibited the lowest activation energy among the tested composites,along with the best protective capability.The inclusion of modified glass powder has a minor impact on the rheological properties,indicating that the composite retains its ability to flow and deform under stress.This confirms that the material remains flexible under normal conditions and forms a ceramic structure when heated,thereby exhibiting self-supporting properties.This study provides a practical methodology for the targeted modification of glass powders,thereby further enhancing the fire safety of silicone-based composites.展开更多
The rapidly growing demand for lithium iron phosphate(LiFePO_(4))as the cathode material of lithium-ion batteries(LIBs)has aggravated the scarcity of phosphorus(P)reserves on Earth.This study introduces an environment...The rapidly growing demand for lithium iron phosphate(LiFePO_(4))as the cathode material of lithium-ion batteries(LIBs)has aggravated the scarcity of phosphorus(P)reserves on Earth.This study introduces an environmentally friendly and economical method of P recovery from municipal wastewater,providing the P source for LiFePO_(4) cathodes.The novel approach utilizes the sludge of Fe-coagulant-based chemical P removal(CPR)in wastewater treatment.After a sintering treatment with acid washing,the CPR sludge,enriched with P and Fe,transforms into purified P-Fe oxides(Fe2.1P1.0O5.6).These oxides can substitute up to 35%of the FePO_(4) reagent as precursor,producing a carbon-coated LiFePO_(4)(LiFePO_(4)/C)cathode with a specific discharge capacity of 114.9 mA·h·g^(-1)at current density of 17 mA·g^(-1)),and cycle stability of 99.2%after 100 cycles.The enhanced cycle performance of the as-prepared LiFePO_(4)/C cathode may be attributed to the incorporations of impurities(such as Ca^(2+)and Na^(+))from sludge,with improved stability of crystal structure.Unlike conventional P-fertilizers,this P recovery technology converts 100%of P in CPR sludge into the production of value-added LiFePO_(4)/C cathodes.The recovered P from municipal wastewater can meet up to 35%of the P demand in the Chinese LIBs industry,offering a cost-effective solution for addressing the pressing challenges of P scarcity.展开更多
In this work,for the first time,it is demonstrated that during the insertion/extraction of Na ions,the structural evolution at the Na_(4)site at a voltage range of 3-4 V is a key factor for the capacity decay of Na_(4...In this work,for the first time,it is demonstrated that during the insertion/extraction of Na ions,the structural evolution at the Na_(4)site at a voltage range of 3-4 V is a key factor for the capacity decay of Na_(4)Fe_(3)(PO_(4))_(2)P_(2)O_(7)(NFPP).Herein,a strategy of introducing columnar potassium ions at the Na_(4)site is proposed to address the aforementioned challenge.As a cathode material for sodium-ion batteries,the K_(0.12)Na_(3.88)Fe_(3)(PO_(4))_(2)P_(2)O_(7)/C(K-NFPP)composite enhances the reversibility of Na_(4)extraction.Specifically,the K-NFPP exhibits an initial discharge capacity of 107.8 mAh g^(-1)at a high current density of 5 C,with a capacity retention of 91.4% after 2000 cycles,outperforming the pristine NFPP material(81.1 m Ah g^(-1)and 67.1%).At 5 C,the K-NFPP also retains 81.5% of the reversible capacity at 0.1 C,whereas the NFPP only retains 68.3%.Moreover,the K-NFPP-based full-cell delivers an initial capacity of 110.1 m Ah g^(-1)at 1 C,with a capacity retention of 90% after 100 cycles.It is found that in comparison to K-doping of the Na1,Na2,and Na3 sites,K-doping at the Na4 site effectively optimizes the band gap and stabilizes the crystal structure,thereby reducing lattice changes of FeO_(6)evolution during Na^(+)insertion/extraction.As a result,the introduction of columnar potassium ions significantly enhances the capacity contribution of the Na_(4)site,optimizes reaction kinetics,and effectively mitigates the capacity decay of NFPP cathodes.It is believed that this study offers a new entry point for the application of NFPP in high-voltage sodium storage.展开更多
The injection of bone cement is a promising surgical intervention for the treatment of osteoporosis.The aim of this study was to formulate a novel injectable bioactive bone cement to adress such medical problems.The b...The injection of bone cement is a promising surgical intervention for the treatment of osteoporosis.The aim of this study was to formulate a novel injectable bioactive bone cement to adress such medical problems.The bone cement primarily consists of tricalcium phosphate(β-TCP),konjac glucomannan(KGM),and hydroxyapatite whisker(HAw).An orthogonal experiment was designed to generate multiple sets of new composite calcium phosphate cement(NCPC)samples,and their setting times were measured.The in vitro compatibility of the new bone cement was assessed through relative cell proliferation rate(RGR)and in vitro cell growth experiments.Mechanical strength and porosity tests were conducted for each group of bone cement,and cross-sectional morphology was observed.The results demonstrate that the bone cement exhibits favorable properties such as self-curing,mechanical robustness,and resistance to collapse.The optimum formulation involves a doping ratio of 5/15(wt%)HAw and HA,an additional amount of 1.2wt%KGM,and a liquid citric acid concentration of 2wt%.Porosity tests confirmed that the material has high compressive strength and a favorable porosity of 27%,creating conducive conditions for cell growth,proliferation,and material degradation.Moreover,in vitro cell culture experiments revealed excellent biocompatibility of the material.Consequently,the developed NCPC emerges as a potential candidate material for applications of bone implantation.展开更多
LiNi_(0.5)Mn_(1.5)O_4(LNMO) was prepared by a high-temperature solid phase method,and then Al PO_(4)(AP) was coated on the polyhedral LNMO surface by the wet chemical method.The experimental results showed that the LN...LiNi_(0.5)Mn_(1.5)O_4(LNMO) was prepared by a high-temperature solid phase method,and then Al PO_(4)(AP) was coated on the polyhedral LNMO surface by the wet chemical method.The experimental results showed that the LNMO-1%AP|Li cell prepared with a 1%mass ratio of Al PO_(4and) LNMO had better electrochemical performance;after 450 cycles at 1C,its discharge specific capacity maintained 108.78 m Ah·g^(-1),while that of the LNMO|Li cell was only 86.04 m Ah·g^(-1).Especially at the high rates of 5C and 10C,the electrochemical properties of the former were far superior to the latter.This was attributed to the fact that the AP coating made the surface of LNMO in contact with the electrolyte more stable,effectively promoted the Li~+transport,and reduced the polarization voltage of the electrode.展开更多
基金supported by grant DY95-08-05 from the China Ocean Mineral Resources R&D Associationthe National Natural Science Foundation of China(Grant 40373002).
文摘A detailed study on a small scale of the effect of phosphatization on the chemistry of marine cobalt-rich ferromanganese crusts supplies useful information for the evaluation and comprehensive utilization of crust mineral resources. Sub-samples from top to bottom of a 10-cm thick sample from the NW Pacific Magellan seamount were taken at 5 mm intervals. The concentration profiles of ore-forming and rare earth elements show that obvious differences exist between young unphosphatized crusts and old phosphatized crusts. In the old crusts Fe, Mn, Si, Al, Zn, Mg, Co, Ni and Cu elements are depleted and Ca, P, Sr, Ba and Pb elements are enriched. The order of depletion is Co > Ni > Mg > Al > Mn > Si> Cu > Zn > Fe, while the order of enrichment is P > Ca > Ba > Pb > Sr. The phosphate mineral controls the concentration variation of the ore-forming elements in crusts and causes loss of the main ore-forming elements such as Co and Ni. The phosphatization also affects the abundance of REEs in the crusts. REEs are more abundant and the content of Ce in old crusts is higher than that in young crusts, however, the pattern of REEs and their fractionation characteristics in new and old crusts are not fundamentally changed. A Y-positive anomaly in old crusts has no relationship to the phosphatization.
文摘In the present paper, iodine （I）, iron （Fe）, manganese （Mn）, cobalt （Co）, phosphorus （P） and calcium （Ca） contents in three ferromanganese crusts from the Pacific Ocean are measured by spectrophotometric method and inductively coupled plasma atomic emission spectrometers （ICP-AES） to investigate the contents and distribution of iodine in ferromanganese crusts. The results show that iodine contents in three crusts vary between 27.1 and 836 mg/kg, with an average of 172 mg/kg, and the profile of iodine in the three crusts all exhibits a two-stage distribution zone： a young non-phosphatized zone and an old phosphatized zone that is rich in I, P and Ca. The iodine content ratios of old to young zone in MP5D44, CXD62-1 and CXD08-1 are 2.3, 3.4 and 13.7, respectively. The boundary depths of two-stage zone in MP5D44, CXD62-1 and CXD08-1 locate at 4.0 cm, 2.5 cm and 3.75 cm, respectively, and the time of iodine mutation in three crusts ranges from 17-37 Ma derived from 129I dating and Co empirical formula, which is consistent with the times of Cenozoic phosphatization events. The present study shows that the intensity of phosphatization is the main responsible for the distribution pattern of iodine in the crusts on the basis of the correlation analysis. Consequently, iodine is a sensitive indicator for phosphatization.
基金funded by MOST Special Fund from the State Key Laboratory of Continental Dynamics, Northwest University, MOST (No. 2011CB808805)NSFC (No. 41172029)
文摘Biomineralization may have an extremely long evolutionary history since the Paleoarchean, while the widespread biomineralization among metazoan lineages started at the earliest Cambrian. However, the primary mineralogy of Anabarites shell remains controversial. Optical microscopic observations combined with the Back-Scattered Electron（BSE） and Energy-Dispersive X-ray Spectroscopy（EDS） analyses are used to study the shell of the fossil Anabarites from the Kuanchuanpu fauna in southern Shaanxi Province in China, which is correlated to the Cambrian Fortunian Stage. The EDS analysis shows that the phosphorus-rich layer closely adjacent to the calcified layer exhibits a Ca： P： C ratio compositionally similar to the mineral fluorapatite（Ca_5（PO_4,CO_3）_3（F,CO_3）. The result that the calcified layer and the phosphorus-rich layer have different chemical compositions is consistent with the optical observation that there is an obvious gap between these two layers and the phosphorus-rich layer can extend to the phosphatic material inside of the tube, suggesting the phosphorus-rich layer doesn＇t belong to the original shell. We suggest that the phosphorous-rich layer is diagenetic in origin, precipitated as a result of phosphorus release during the decay of organic matter by microbes. Considering the outermost shell layer（OMS, biologically controlled carbonate shell layer） should display different isotopic information from the carbonate matrix（i.e., OMS is ^（12）C concentrated due to the biogenic organic matter template is readily rich in ^（12）C）, Nano SIMS was used to map ion distributions of C and N in the shell of Anabarites and matrix. However, ion images show that the concentration differences of ^（12）C, ^（13）C and ^（26）CN among the OMS and the matrix are unclear, while ^（12）C and ^（26）CN are supposed to be enriched in the OMS. Therefore, the minor isotopic differences between the shell and the matrix is hard to be detected by Nano SIMS, at least in our sample, probably due to alteration of the ^（12）C-rich characteristic of the Anabarites OMS during the late diagenesis.
文摘It was ascertained that when a RE element was added in bath,the sample was improved on the anti-corrosion power of the coating because of the increasing of covering rate of formless crystal Zn2Fe(PO4) 2·4H2O(marked P) crystals and the ratio of P/(P+H) (H was the mark of Zn3(PO4) 2 crystal) in the coating,combination of which with components parsing by EDS indicated that the sequence of contribution elements P and Zn to erosion resistance of coatings was P】Zn. And the correlative mechanism was discussed,which made it clear that owing to the particularity of the outer-shell electron structure and larger ionic radius,RE was so easy to be polarized and metamorphosed itself that it adsorbed lightly on the basic body to pose gels. They efficiently reduced the activation energy which was required for formation of a new solid phase of phosphates and made it also possible to engender effectively active nucleation regions of cathode and anode under low temperature phosphating condition,which was propitious to formation,densification and uniformization of the phosphate crystal nucleus and growth of the crystallite and coating buildup. Thus it could be seen that REN played the role of surface regulator and accelerant,which speeded up the phosphating,as well as bids amount of porosity of the coating fall to improve the corrosion resistance of the coating.
基金supported by the National Natural Science Foundation of China(Grant Nos.92262304,40473024,40343019)the National Key R&D Program of China during the 13th Five-year Plan Period(Grant No.DY135-R2-1-01)。
文摘Oceanic phosphatization events episodically precipitate carbonate fluorapatite(CFA),inducing phosphatization of ferromanganese crusts and significantly influencing rare earth elements plus yttrium(REY)and associated metal concentrations.Western Pacific ferromanganese crusts archive multiple phosphatization events,yet the absence of accurate chronological constraints hindered detailed investigations into the mechanisms of REY redistribution during distinct phosphatization episodes.Building upon previously established phosphatization events through CFA U-Pb geochronology,this study investigates three ferromanganese crusts from different water depths on Ita Mai Tai Guyot(Western Pacific)to evaluate the impacts of phosphatization on REYenrichment.Results show that all three hydrogenetic crusts experienced phosphatization,with phosphatized layers exhibiting higher average REY concentrations(2090,1885,and 1854 ppm)than non-phosphatized layers(1413,1174,and 1519 ppm),indicating that phosphatization enhances REYenrichment.However,when the crusts are precisely divided based on phosphatization episodes,one phosphatized layer(1293 ppm)exhibits lower REY concentrations than the unphosphatized layer(1413 ppm).This is attributed to a dilution effect from the precipitation of REY-poor authigenic CFA;the apatite within this specific layer contains only 602 ppm REY,a value lower than that of the unphosphatized crust.Concurrently,“REY-rich”veinlike CFA(2703 ppm)is associated with slow depositional processes,indicating its potential to increase the REY content of crusts.Therefore,this study reveals the dual role of phosphatization on REY enrichment.It can either promote enrichment by enhancing REY adsorption onto iron-manganese oxides and by forming REY-rich CFA,or cause dilution through the precipitation of REY-poor CFA.The net effect is ultimately controlled by a combination of environmental factors,including sedimentation rate and water depth,revealing the complex mechanisms of REY in phosphatized ferromanganese crusts.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFF0803600)National Natural Science Foundation of China(Grant Nos.42302009,42072003,and W2441016)+3 种基金HYZ thanks the Shaanxi Province postdoctoral research project and China Scholarship Council(202306970031)We also thank the Department of Science and Technology of Shaanxi Province(2022TD-11)TPT also acknowledges the Swedish Research Council(VR2017-05183 and VR2021-04295)This is also a contribution to the project of Theory of Hydrocarbon Enrichment under MultiSpheric Interactions of the Earth(THEMSIE04010106).
文摘Small shelly fossils(SSFs)have long been recognized as important to the studies of both metazoan evolution and the onset of biomineralization during the Cambrian radiation.The marked decline in the occurrence,diversity and abundance of SSFs in the middle to late Cambrian,when compared with the early Cambrian,has often been regarded as a result of the closure of a phosphatization window.Despite this,there have been numerous and consistent reports of SSFs from the middle Cambrian and younger deposits.To identify possible factors influencing SSF preservation,five microfacies including bioclastic limestone,flat-pebble conglomerates with bioclasts,hummocky cross-stratified grainstone with bioclasts,bioclastic grainstone in hardgrounds and glauconite bioclastic wackstone-packstone,from Cambrian Series 2 to Miaolingian in North China are compared to assess how differences in lithology impact the preservation potential of SSFs.Our results,based on 35,161 SSF specimens from deposits across six sections,suggest that there are still abundant and diverse SSFs in the middle Cambrian of North China preserved in ways not exclusively reliant on the presence of phosphate and that SSF preservation can be linked to the differences in microfacies in the early to middle Cambrian of North China.
基金financially supported by the National Natural Science Foundation of China(Nos.82203680 and 52273278)the Natural Scientific Foundation of Liaoning Province(No.2021-MS-176)+1 种基金Shenyang Bureau of Science and Technology(No.RC230527)the Central Guidance Funding for Local Scientific and Techno-logical Development in Liaoning(No.2023JH6/100100029).
文摘Guided bone regeneration in the alveolar bone relies on the colonization and differentiation of immune cells within the defect area.The absence of osteoinductive and osteoimmune properties of currently available scaffolds hinders to achieve optimal repair outcomes in clinical settings.Thus,we aimed to enhance the bone repair ability of polycaprolactone(PCL)scaffolds by incorporating osteoinductive amorphous calcium phosphate(ACP)with immune-regulating zinc ions(ACP(Zn),ACZP),to create a favorable immunomodulatory microenvironment.After one day of co-culture with PCL-ACZP,the spreading area of macrophage cells was significantly higher than that from the original PCL scaffold.Additionally,over 32.1%of macrophages exhibited M2 polarization within three days of co-culture.The PCLACZP/macrophage-conditioned medium significantly boosted osteogenic gene expression in MC3T3-E1 cells.After eight weeks of implantation in a rat femoral condyle defect,the BV/TV from the PCL-ACZP group reached 32.9%,1.4 times of that from the PCL group.Furthermore,the PCL-ACZP-GelMA biphasic module as prepared successfully achieved complete regeneration of three-walled alveolar bone defects in rabbits,resulting in arch-shaped alveolar bone repair and providing greater convenience in the clinical settings.This study showcased the effectiveness of PCL-ACZP-GelMA biphasic module as bioactive scaffolds in the morphological restoration of alveolar bone.
基金National Natural Science Foundation of China(52104294)Fundamental Research Funds for the Central Universities(FRF-TP-19-079A1)。
文摘The soaring demand for smart portable electronics and electric vehicles is propelling the advancements in high-energy–density lithium-ion batteries.Lithium manganese iron phosphate(LiMn_(x)Fe_(1-x)PO_(4))has garnered significant attention as a promising positive electrode material for lithium-ion batteries due to its advantages of low cost,high safety,long cycle life,high voltage,good high-temperature performance,and high energy density.Although LiMn_(x)Fe_(1-x)PO_(4)has made significant breakthroughs in the past few decades,there are still facing great challenges in poor electronic conductivity and Li-ion diffusion,manganese dissolution affecting battery cycling performance,as well as low tap density.This review systematically summarizes the reaction mechanisms,various synthesis methods,and electrochemical properties of LiMn_(x)Fe_(1-x)PO_(4)to analyze reaction processes accurately and guide material preparation.Later,the main challenges currently faced are concluded,and the corresponding various modification strategies are discussed to enhance the reaction kinetics and electrochemical performance of LiMn_(x)Fe_(1-x)PO_(4),including multi-scale particle regulation,heteroatom doping,surface coating,as well as microscopic morphology design.Finally,in view of the current research challenges faced by intrinsic reaction processes,kinetics,and energy storage applications,the promising research directions are anticipated.More importantly,it is expected to provide key insights into the development of high-performance and stable LiMn_(x)Fe_(1-x)PO_(4)materials,to achieve practical energy storage requirements.
基金support of the PID2021-124341OB-C22/AEI/10.13039/501100011033/FEDER,UE(MICIU)J.M.Vega also acknowledges the Grant RYC2021-034384-I funded by MICIU/AEI/10.13039/501100011033 and by“European Union Next Generation EU/PRTR”.
文摘In this study,a phosphate-based conversion coating(PCC)was applied as a precursor before forming silicate-fluoride(SiF)and silicate-phosphate-fluoride(SiPF)based flash-plasma electrolytic oxidation(Flash-PEO)coatings on AZ31B magnesium alloy.The main novelty is the successful incorporation of calcium,zinc,manganese and phosphate species into the Flash-PEO coatings via a precursor layer rather than using the electrolyte.The precursor also led to longer lasting and more intense discharges during the PEO process,resulting in increased pore size.Corrosion studies revealed similar short-term performance for all coatings,with impedance modulus at low frequencies above 10^(7)Ωcm^(2),and slightly better performance for the SiPF-based coating.Nonetheless,the enlarged pores in the PEO coatings functionalized with the PCC precursor compromised the effectiveness of self-healing mechanisms by creating diffusion pathways for corrosive species,leading to earlier failure.These phenomena were effectively monitored by recording the open circuit potential during immersion in 0.5 wt.%NaCl solution.In summary,this study demonstrates that conversion coatings are a viable option for the functionalization of PEO coatings on magnesium alloys,as they allow for the incorporation of cationic and other species.However,it is crucial to maintain a small pore size to facilitate effective blockage through self-healing mechanisms.
基金financed by the Spanish Ministry of Science and Innovation and the European Regional Development Fund(ERDF)(No.PID20211234690BI00)the European Joint Program EJP_Soil(TRACE-Soils)(No.862695)+1 种基金the Spanish Ministry of Science and Innovation(RED2018-102624TMCIN/AEI/10.13039/501100011033)the Project PREPSOIL European Union(No.101070045,HORIZON CSA)。
文摘Whilst phosphorus(P)in soil is considered to be abundant,the portion available for plant uptake constitutes less than 1%of the overall P present.To enhance crop productivity,the utilization of mineral P fertilizers has become pervasive in agriculture.Nonetheless,the escalating prices of chemical fertilizers,coupled with new European regulations prohibiting the use of P fertilizers containing cadmium,have highlighted the urgency to identify environmentally friendly products and practices for P fertilization in agricultural soils.This comprehensive review delves into the current landscape of P fertilization from agricultural,political,and economic standpoints.We recognize the potential of microbes in mobilizing P,but emphasize the necessity for more robust research to establish their effectiveness in promoting plant P uptake under real-world conditions.Additionally,we explore the role of agricultural conservation practices,such as optimal tillage,diversified cropping systems,and increased organic carbon input,in conserving P.Furthermore,this review contemplates forthcoming innovations in research.These innovations encompass the development of enhanced formulations for biofertilizers and the undertaking of more comprehensive studies within the realm of conservation agriculture.All these endeavors collectively hold the potential to augment P accessibility to plants in a sustainable manner,thereby advancing agricultural sustainability and productivity.
基金supported by Hebei Key Laboratory of Mineral Resources and Ecological Environment Monitoring(No.HBMREEM202302)Tianjin Key Research and Development Science and Technology Project(Nos.24YFXTHZ00170 and 24YFXTHZ00050)。
文摘The interaction mechanism between eggshell calcium and endogenous silica in biomass during biochar modification,and its impact on phosphate adsorption performance and slow-release fertilizer characteristics,remains unexplored.This study investigates that high silica content in biomass(>6%)inhibits the decomposition of CaCO_(3)in eggshells during pyrolysis,reducing the formation of active calcium species(CaO and Ca(OH)_(2)),while moderate silica levels(4%-5%)promote the formation of CaSiO_(3),enhancing phosphorus adsorption without hindering Ca^(2+)activation.Adsorption studies reveal that the precipitation of Ca_(5)(PO_(4))_(3)(OH)resulting from the combination of CaO and Ca(OH)_(2)with phosphate is the primary and effective form for phosphorus removal in calcium-modified adsorbents,accompanied by Ca_(3)(PO_(4))_(2)·2H_(2)O precipitation formed by CaSi O_(3).Eggshell calcium-modified corn straw biochar(ECS)exhibited the highest adsorption capacity,reaching 123.3 mg/g,outperforming materials in previous studies.ECS also demonstrated excellent pH adaptability and selective phosphate removal.As a biochar-based phosphorus fertilizer,ECS-P exhibits high phosphorus extractability in formic acid(93.92%)but low water solubility(0.62%),with phosphorus release during the seven-day intermittent leaching experiment remaining between 0.53 to 0.875 mg/L.These results confirm its potential as a phosphorus cycling fertilizer.This study provides fundamental insights into optimizing biomass selection based on silica content for calcium modification,offering an efficient strategy for both phosphate recovery and slow-release fertilizer development.
基金supported by the Chilwee Group(No.CWDY-ZH-YJY-202101-001)the Fundamental Research Funds for the Central Universities(No.2042023kf0214)the Starting Funding from Wuhan University.
文摘The efficient recycling of spent lithium iron phosphate(LiFePO_(4),also referred to as LFP)should convert Fe(Ⅱ)to Fe(Ⅲ),which is key to the extraction of Li and separation of Fe and is not well understood.Herein,we systematically study the oxidation of LiFePO_(4)in the air and in the solution containing oxidants such as H_(2)O_(2)and the effect of oxidation on the leaching behaviors of LFP.In the air,O_(2)breaks down the LFP olivine structure at 550℃for 1 h by oxidizing Fe(Ⅱ)to Fe(Ⅲ)in terms of converting LFP to Li_(3)Fe_(2)(PO_(4))_(3)and Fe_(2)O_(3).After that,Li is leached in 0.5 M sulfuric acid solution and is further recycled as Li_(3)PO_(4)with a Li recovery efficiency of 97.48%.Meanwhile,Fe is recovered as FePO_(4)and Fe_(2)O_(3).Compared with H_(2)SO_(4)-H_(2)O_(2),the air oxidation saves H_(2)O_(2)but increases the leaching efficiency of Fe and H_(2)SO_(4)consumption.The discrepancy of Fe leaching efficiency can be attributed to the different leaching mechanisms involving the solid-to-solid and solid-to-liquid-to-solid conversions.Furthermore,the results of the Everbatt model analysis show that the air roasting-H_(2)SO_(4)leaching method has low emission and potentially high income,which is simple and safe.Overall,this work will deepen the understanding of acid leaching of LFP and favorably stimulate the maturation of the LFP recycling technique.
基金supported by the National Natural Science Foundation of China(52127801)Postdoctoral Fellowship Program of CPSF under Grant Number GZC20231545,China Postdoctoral Science Foundation(2024T170557 and 2023M742224)+1 种基金Shanghai Post-doctoral Excellence Program(No.2023440)City University of Hong Kong Donation Grants(DON-RMG No.9229021 and 9220061).
文摘Pure Mg boasting a relatively small corrosion rate is a potential biodegradable metal material for implants.However,its degradation behavior in the complex physiological environment is still a lack of understanding.In this work,we investigated the effect of corrosion product film layers on the degradation behavior of pure Mg in physiological environments.Pure Mg shows a faster corrosion rate in simulated body fluid(SBF)compared to NaCl solution.Hydrogen evolution experiments indicate that the degradation rate of pure Mg in SBF decreases rapidly within the first 12 h but stabilizes afterward.The rapid deposition of low-solubility calcium phosphate on the pure Mg in SBF provides protection to the substrate,resulting in a gradual decrease in the degradation rates.Consequently,the corrosion product film of pure Mg formed in SBF exhibits a layered structure,with the upper layer consisting of dense Ca_(3)(PO_(4))_(2)/Mg_(3)(PO_(4))_(2) and the lower layer consisting of Mg(OH)_(2)/MgO.Electrochemical impedance spectroscopy(EIS)shows that the resistance of the corrosion product film increases over time,indicating gradual strengthening of the corrosion resistance.The 4-week degradation results in the femoral marrow cavity of mice are consistent with the result in SBF in vitro.
基金the support of this research by the National Natural Science Foundation of China (No. 22179034)the Natural Science Foundation of Heilongjiang Province (No. ZD2023B002)。
文摘Developing high-efficient and low-loading Pt based catalyst is significant for the electrocatalytic p Huniversal hydrogen evolution reaction(HER). Herein, the molybdenum carbide nanoparticles supported on the polyhedral N-doped carbon nanotube skeleton(Mo C/NCT) composite has been synthesized by a pyrolysis of polyacid organo-metallic phosphate framework precursor. Then, only 2.15 wt% Pt are loaded on the Mo C/NCT to form Pt-Mo C/NCT catalyst, which performs superior HER activity and stability in entire p H range. Specially, the overpotentials of 22 and 74 m V are respectively attained at 10 m A/cm^(2) in1.0 mol/L KOH and 0.5 mol/L H_(2)SO_(4) electrolytes, approaching or even exceeding commercial Pt/C. More importantly, it can be used as excellent catalyst for efficient hydrogen production at 0–14 p H range. Density functional theory(DFT) calculations demonstrate that the interaction between Mo C and Pt leads to the electron redistribution at the corresponding interfaces and the downward shift of the d-band centers, thus optimizing H*adsorption and desorption for promoting the HER activity. Besides, the unique three-dimensional network structure is conductive to the transmission of mass and electrons. In the application of both alkaline and acidic electrolysers, only 1.52 V voltage of solar panel can drive a hydrogen production current density of 10 m A/cm^(2).
基金financially supported by the National Natural Science Foundation of China(No.52174340)the National Key Research and Development Project of China(No.2022YFC2904505)the Hunan FURONG Scholars Project and the Basic Science Centre of the National Natural Science Foundation of China(No.72088101)。
文摘Potassium hydroxide(KOH)was introduced into the molybdenite roasting process to convert molybdenum(Mo)and sulfur(S)into water-soluble potassium molybdate(K_(2)MoO_(4))and potassium sulfate(K_(2)SO_(4)).Roasting with a 1.8-fold excess of KOH at 400℃ for 3 h enabled the leaching of over 99%of Mo from the molybdenum calcine using water.A precipitation method involving potassium–magnesium(K-Mg)salts was proposed for impurity removal.Under the conditions of pH 11,30℃,excess coefficient of 1.7 for Mg salts,and a duration of 1 h,98.37%of phosphorus(P)was removed from the K_(2)MoO_(4) solution.With post-purification,over 99%of Mo crystallized upon adjustment of pH to 1.Subsequently,S and K were recovered as K_(2)SO_(4) fertilizer from the crystalline mother liquor.An environmentally sustainable approach was proposed to conduct molybdenite production and ensure the efficient recovery of both Mo and S.
基金supported by National Natural Science Foundation of China(51991352 and 51874266).
文摘Silicone rubber(SR)exhibits superior breathability and high-temperature resistance.However,SR is prone to degradation under extreme heat or combustion,limiting its effectiveness in mitigating secondary hazards.In this study,phosphate glass powder was used to calcinate zinc borate,lanthanum oxide,and cerium oxide.Methylphenyl polysiloxane was then grafted onto the surface of the glass powder,resulting in the modified pow-ders designated as Methylphenyl polysiloxane-grafted zinc borate-modified phosphate glass powder(GF-ZnBM),Methylphenyl polysiloxane-grafted lanthanum oxide-modified phosphate glass powder(GF-LaM),and Methylphenyl polysiloxane-grafted cerium oxide-modified phosphate glass powder(GF-CeM).The modified powders were sub-sequently incorporated into silicone rubber composites to enhance the ceramicization capability of silicone rubber at high temperatures.Specifically,GF-CeM and GF-LaM significantly increased the limiting oxygen index(LOI)to 33%and reduced the tendency for combustion propagation.Additionally,GF-CeM notably contributed to enhancing ceramicization strength.The presence of cerium oxide helps in the melting of the glass powder and enhances its adhesion to the silicone rubber matrix.SR/ZnB-GF exhibited the lowest activation energy among the tested composites,along with the best protective capability.The inclusion of modified glass powder has a minor impact on the rheological properties,indicating that the composite retains its ability to flow and deform under stress.This confirms that the material remains flexible under normal conditions and forms a ceramic structure when heated,thereby exhibiting self-supporting properties.This study provides a practical methodology for the targeted modification of glass powders,thereby further enhancing the fire safety of silicone-based composites.
基金supported by the National Natural Science Foundation of China(52100093,52270128,and 52261135627)the Guangdong Basic and Applied Basic Research Foundation(2023A1515011734 and 2021B1515120068)+2 种基金the Municipal Science and Technology Innovation Council of the Shen-zhen Government(KCXFZ20211020163556020 and SGDX20230116092359002)the Research Grants Council(17210219)the Innovation and Technology Fund(ITS/242/20FP)of the Hong Kong SAR Government。
文摘The rapidly growing demand for lithium iron phosphate(LiFePO_(4))as the cathode material of lithium-ion batteries(LIBs)has aggravated the scarcity of phosphorus(P)reserves on Earth.This study introduces an environmentally friendly and economical method of P recovery from municipal wastewater,providing the P source for LiFePO_(4) cathodes.The novel approach utilizes the sludge of Fe-coagulant-based chemical P removal(CPR)in wastewater treatment.After a sintering treatment with acid washing,the CPR sludge,enriched with P and Fe,transforms into purified P-Fe oxides(Fe2.1P1.0O5.6).These oxides can substitute up to 35%of the FePO_(4) reagent as precursor,producing a carbon-coated LiFePO_(4)(LiFePO_(4)/C)cathode with a specific discharge capacity of 114.9 mA·h·g^(-1)at current density of 17 mA·g^(-1)),and cycle stability of 99.2%after 100 cycles.The enhanced cycle performance of the as-prepared LiFePO_(4)/C cathode may be attributed to the incorporations of impurities(such as Ca^(2+)and Na^(+))from sludge,with improved stability of crystal structure.Unlike conventional P-fertilizers,this P recovery technology converts 100%of P in CPR sludge into the production of value-added LiFePO_(4)/C cathodes.The recovered P from municipal wastewater can meet up to 35%of the P demand in the Chinese LIBs industry,offering a cost-effective solution for addressing the pressing challenges of P scarcity.
基金financial support from the National Natural Science Foundation of China(52272237,22279101 and 22172117)the Natural Science Foundation of Shaanxi(2020JC-41 and 2024JC-YBQN-0141)+2 种基金the Scientific Research Program Funded by the Education Department of Shaanxi Provincial Government(22JP056)the S&T Program of Energy Shaanxi Laboratory(ESLB202402)the Foshan Science and Technology Innovation Team Project(1920001004098)。
文摘In this work,for the first time,it is demonstrated that during the insertion/extraction of Na ions,the structural evolution at the Na_(4)site at a voltage range of 3-4 V is a key factor for the capacity decay of Na_(4)Fe_(3)(PO_(4))_(2)P_(2)O_(7)(NFPP).Herein,a strategy of introducing columnar potassium ions at the Na_(4)site is proposed to address the aforementioned challenge.As a cathode material for sodium-ion batteries,the K_(0.12)Na_(3.88)Fe_(3)(PO_(4))_(2)P_(2)O_(7)/C(K-NFPP)composite enhances the reversibility of Na_(4)extraction.Specifically,the K-NFPP exhibits an initial discharge capacity of 107.8 mAh g^(-1)at a high current density of 5 C,with a capacity retention of 91.4% after 2000 cycles,outperforming the pristine NFPP material(81.1 m Ah g^(-1)and 67.1%).At 5 C,the K-NFPP also retains 81.5% of the reversible capacity at 0.1 C,whereas the NFPP only retains 68.3%.Moreover,the K-NFPP-based full-cell delivers an initial capacity of 110.1 m Ah g^(-1)at 1 C,with a capacity retention of 90% after 100 cycles.It is found that in comparison to K-doping of the Na1,Na2,and Na3 sites,K-doping at the Na4 site effectively optimizes the band gap and stabilizes the crystal structure,thereby reducing lattice changes of FeO_(6)evolution during Na^(+)insertion/extraction.As a result,the introduction of columnar potassium ions significantly enhances the capacity contribution of the Na_(4)site,optimizes reaction kinetics,and effectively mitigates the capacity decay of NFPP cathodes.It is believed that this study offers a new entry point for the application of NFPP in high-voltage sodium storage.
文摘The injection of bone cement is a promising surgical intervention for the treatment of osteoporosis.The aim of this study was to formulate a novel injectable bioactive bone cement to adress such medical problems.The bone cement primarily consists of tricalcium phosphate(β-TCP),konjac glucomannan(KGM),and hydroxyapatite whisker(HAw).An orthogonal experiment was designed to generate multiple sets of new composite calcium phosphate cement(NCPC)samples,and their setting times were measured.The in vitro compatibility of the new bone cement was assessed through relative cell proliferation rate(RGR)and in vitro cell growth experiments.Mechanical strength and porosity tests were conducted for each group of bone cement,and cross-sectional morphology was observed.The results demonstrate that the bone cement exhibits favorable properties such as self-curing,mechanical robustness,and resistance to collapse.The optimum formulation involves a doping ratio of 5/15(wt%)HAw and HA,an additional amount of 1.2wt%KGM,and a liquid citric acid concentration of 2wt%.Porosity tests confirmed that the material has high compressive strength and a favorable porosity of 27%,creating conducive conditions for cell growth,proliferation,and material degradation.Moreover,in vitro cell culture experiments revealed excellent biocompatibility of the material.Consequently,the developed NCPC emerges as a potential candidate material for applications of bone implantation.
文摘LiNi_(0.5)Mn_(1.5)O_4(LNMO) was prepared by a high-temperature solid phase method,and then Al PO_(4)(AP) was coated on the polyhedral LNMO surface by the wet chemical method.The experimental results showed that the LNMO-1%AP|Li cell prepared with a 1%mass ratio of Al PO_(4and) LNMO had better electrochemical performance;after 450 cycles at 1C,its discharge specific capacity maintained 108.78 m Ah·g^(-1),while that of the LNMO|Li cell was only 86.04 m Ah·g^(-1).Especially at the high rates of 5C and 10C,the electrochemical properties of the former were far superior to the latter.This was attributed to the fact that the AP coating made the surface of LNMO in contact with the electrolyte more stable,effectively promoted the Li~+transport,and reduced the polarization voltage of the electrode.
