A novel graphene oxide/titanium dioxide（GO/TiO2） solvent-free nanofluid was firstly synthesized by employing GO, which was in-situ deposited by TiO2 as the core and（3-Glycidyloxypropyl） trime thoxysilane（KH560） ...A novel graphene oxide/titanium dioxide（GO/TiO2） solvent-free nanofluid was firstly synthesized by employing GO, which was in-situ deposited by TiO2 as the core and（3-Glycidyloxypropyl） trime thoxysilane（KH560） and polyetheramine-M2070 as the shell. The morphology and structure of GO/TiO2 nanofluid were verified by Transmission electron microscopy（TEM）, X-ray diffraction（XRD） analysis, Fourier transform infrared spectroscopy（FTIR）, X-ray photoelectron spectroscopy（XPS） and UV-vis absorption spectra. These studies confirmed that TiO2 has been deposited onto GO with good dispersion, and the organic shell has been grafted onto the core successfully. Thermo gravimetric analysis（TGA） and viscosity analysis indicated that this nanoparticle hybrid material presented a liquid state without solvent at room temperature, and has great fluidity and thermal stability. The solubility investigation of GO/TiO2 nanofluid revealed its excellent amphiphilicity and the potential as the functional nanocomposites.展开更多
Three-dimensional(3D)porous absorbents have attracted significant attention in the oily wastewater treatment technology due to their high porosity and elasticity.Given their amphiphilic surface,they have a propensity ...Three-dimensional(3D)porous absorbents have attracted significant attention in the oily wastewater treatment technology due to their high porosity and elasticity.Given their amphiphilic surface,they have a propensity to simultaneously absorb water and oil,which restricts their range of applications.In this study,a reduced graphene oxide and titanium dioxide nanocomposite(rGO/TiO_(2))was used to fabricate an ultra-hydrophobic melamine sponge(MS)through interfacial modification using a solution immersion technique.To further modify it,poly-dimethylsiloxane(PDMS)was grafted onto its surface to establish stronger covalent bonds with the composite.The water contact angle of the sponge(rGO/TiO_(2)/PDMS/MS)was 164.2°,which satisfies the condition for ultrahydrophobicity.The evidence of its water repellency was demonstrated by the Cassie-Baxter theory and the lotus leaf effect.As a result of the increased density of rGO/TiO_(2)/PDMS/MS,it recorded an initial capacity that was 2 g/g lower than the raw MS for crude oil absorption.The raw MS retained 53% of its initial absorption capacity after 20 cycles of absorption,while rGO/TiO_(2)/PDMS/MS retained 97%,suggesting good recyclability.Excellent oil and organic solvent recovery(90%-96%)was demonstrated by rGO/TiO_(2)/PDMS/MS in oil-water combinations.In a continuous separation system,it achieved a remarkable separation efficiency of 2.4×10^(6)L/(m^(3)·h),and in turbulent emulsion separation,it achieved a demulsification efficiency of 90%-91%.This study provides a practical substitute for massive oil spill cleaning.展开更多
A stable and insoluble V2O5·n H2O/tetra-n-butyl titanate（TBO） hybrid xerogel was synthesized by the sol–gel method. This novel material proved to be an efficient absorbent with an absorption capacity of 179 mg...A stable and insoluble V2O5·n H2O/tetra-n-butyl titanate（TBO） hybrid xerogel was synthesized by the sol–gel method. This novel material proved to be an efficient absorbent with an absorption capacity of 179 mg·g^-1for Rhodamine B（Rh B） in water due to its unique layered structure, which can effectively accommodate Rh B molecules between its layers as demonstrated by XRD and FTIR spectroscopic analyses.展开更多
Colitis-associated colorectal cancer(CAC)is a major contributor to cancer-related mortality worldwide.Titanium dioxide(TiO_(2),E171),a widely used food additive,has been insufficiently studied regarding its effects on...Colitis-associated colorectal cancer(CAC)is a major contributor to cancer-related mortality worldwide.Titanium dioxide(TiO_(2),E171),a widely used food additive,has been insufficiently studied regarding its effects on macrophages within colon tumors during CAC development.In this study,CAC mouse models were used to investigate the biological impact of dietary E171 on macrophages in vivo,while lipopolysaccharide(LPS)-stimulated RAW264.7 macrophage cell lines were employed to elucidate the underlying mechanisms in vitro.We found that dietary E171 intake accelerated CAC development,exacerbated inflammatory responses and oxidative stress,and upregulated CAC-associated genes,including S100a8,S100a9,Lcn2,S100a11,Cxcl2,and interleukin-1α(Il-1α).E171 also increased the expression of S100A8,S100A9,NOD-like receptor family pyrin domain-containing 3(NLRP3),and gasdermin-D Nterminal(GSDMD-N)in macrophages within colon tumors.In inflammatory macrophages,E171 exposure enhanced cell viability,increased reactive oxygen species(ROS)levels,and elevated the expression and secretion of S100A8 and S100A9,consistent with in vivo histological observations.Furthermore,E171-induced secretion of S100A8 and S100A9 in macrophages was suppressed by specific inhibitors,including N-acetylcysteine(NAC,ROS inhibitor),MCC950(NLRP3 inhibitor),Z-YVAD-FMK(caspase 1 inhibitor),disulfiram(GSDMD inhibitor),and transfection of NLRP3 small interfering ribonucleic acid(siRNA).These results indicate that dietary E171 promotes CAC development by activating macrophages,with S100A8 and S100A9 serving as key mediators,and the NLRP3/caspase 1/GSDMD pathway acting as a critical mechanism.展开更多
Propylene oxide(PO)is an important petrochemical materials used to produce downstream products such as propylene glycol(PG),polyether polyols,and dipropylene glycol(DPG).Among these,DPG is commonly used as a solvent f...Propylene oxide(PO)is an important petrochemical materials used to produce downstream products such as propylene glycol(PG),polyether polyols,and dipropylene glycol(DPG).Among these,DPG is commonly used as a solvent for fragrances,cosmetics,food additives,and detergents,and can also be served as a moisturizer in cosmetics,showing broad application prospects.The distribution of DPG isomers in the products synthesized from PO and PG has a significant impactΔrGΔrHΔfHθΔfGθPO+PG⇌DPG PO+DPG⇌TPG PG+PG⇌DPG+H_(2)O PG+DPG⇌TPG+H_(2)O on the quality of the products.Therefore,conducting thermodynamic calculation on the reaction of PO and PG to synthesize DPG can provide a theoretical basis for practical operations and product distribution regulation.So,in this paper,the thermodynamic parameters of PO,1,2-PG,H_(2)O,tripropylene glycol(TPG)and three isomers of DPG under different reaction conditions is calculated.Additionally,the,and lnK for four potential reactions at various reaction temperatures and pressures are calculated.By designing isodesmic reactions and combining the results of thermodynamic calculations,the and for the isomers of DPG are obtained,and the relative error is less than 7%.The results show that in the process of preparing DPG by PO and PG,when PO∶PG=1,the reaction temperature ranges from 298.15 to 413.15 K,and the pressure ranges from 101.325 to 506.625 kPa,the reactions of and are thermodynamically spontaneous.While the reactions of and are thermodynamically unspontaneous.The optimal reaction temperature and pressure are 413.15 K and 101.325 kPa.The thermodynamic stability of the three isomers is DPG1>DPG2>DPG3 under standard conditions.The accuracy of the computational results is verified through experimental design,and based on this,the factors affecting product distribution are analyzed.展开更多
Black nickel coatings have emerged as a research hotspot in materials science due to their excellent performance and broad application prospects.In this study,nickel-based black coatings were fabricated on low-carbon ...Black nickel coatings have emerged as a research hotspot in materials science due to their excellent performance and broad application prospects.In this study,nickel-based black coatings were fabricated on low-carbon steel substrates via photo-assisted electrodeposition.A systematic investigation was conducted on the effects of cerium ion concentration and nano-ceria(CeO_(2))particle content in the electrolyte on the coating properties,along with an analysis of the temporal evolution of coating’s corrosion resistance.When the cerium ion concentration in the electrolyte was 0.05 mol/L,the coating exhibited a uniform black appearance with a light absorption rate of 95%,an emissivity of 0.87,maximum impedance,and the lowest corrosion tendency,demonstrating optimal comprehensive performance.The coating prepared with a nano-ceria concentration of 6 g/L in the electrolyte exhibited an emissivity of 0.9,achieved a 5B adhesion grade(ASTM D3359-09),and demonstrated a one-order-of-magnitude reduction in corrosion current density compared to coatings fabricated without nano-ceria in the electrolyte.With prolonged storage time,the coating's impedance slightly increased,leading to improved corrosion resistance.展开更多
It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions(<400℃).In this work,five Fe-Ce-La oxides were prepared by co-precipitation method,...It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions(<400℃).In this work,five Fe-Ce-La oxides were prepared by co-precipitation method,and FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbents were prepared by coupling fly ash-based Si-Al carriers.The active components Fe-Ce-La oxides and Si-Al carriers were characterized by TPD,TG,XRF,BET and XPS,respectively.The effects of temperature,Si/Al ratio and FeCeLaO loading rate on the sulfur resistance were investigated.Results show that the SO_(2) promotes the arsenic removal of Fe_(2)O_(3),CeLaO and FeCeLaO.At 400℃,the arsenic removal efficiencies of the three oxides increase from 45.3%,72.5% and 81.3% without SO_(2) to 62.6%,80.5%and 91.0%,respectively.The SO_(2) inhibits the arsenic removal of La_(2)O_(2)CO_(3) and FeLaO,and the inhibition effect is pronounced at high temperatures.The sulfur poisoning resistance of Si-Al carriers increases with the increase of Si/Al ratio.When the Si/Al ratio is increased to 9.74,the arsenic removal efficiency in the SO_(2) environment is 13.9% higher than that in the absence of SO_(2).Introducing FeCeLaO active components is beneficial for enhancing the SO_(2) poisoning resistance of Si-Al carriers.The strong sulfur resistance of the FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbent results from multiple factors:protective effects of Ce on Fe,La and Al;sulfation-induced generation of Ce^(3+)and surface-adsorbed oxygen;and strong surface acidity of SiO_(2).展开更多
Lithium-ion batteries(LIBs)that reached their end-of-life(EoL)require recycling,rather than disposal,to recirculate valuable metals and protect the environment.This led us to investigate the extraction of metals from ...Lithium-ion batteries(LIBs)that reached their end-of-life(EoL)require recycling,rather than disposal,to recirculate valuable metals and protect the environment.This led us to investigate the extraction of metals from the cathodes of EoL lithium-titanate batteries using ethylenediaminetetraacetic acid disodium(EDTA-2Na).In this work,an orthogonal array was used to design experiments and sig-nal-to-noise calculations were used to define the optimal conditions,which were 0.50 mol/L EDTA-2Na,pH=6,75℃,180 min,2%pulp density,and 300 r/min,resulting in 97.96%,94.79%,96.45%,and 98.89%leaching efficiencies for Li,Ni,Co,and Mn,respectively.Stat-istically significant interactions between variables were then identified using Pearson’s correlation at the 95%confidence interval,and the pH and temperature were found to be significant.The extraction efficiency decreased as the pH increased,but increased as the temperat-ure increased.Machine learning fitting using linear regression for multi-output prediction was unsatisfactory,whereas random forest re-gression(RFR)produced satisfactory results.Permutation importance was computed on the fitted RFR to determine feature importance,and confirmed that the pH and temperature were influential variables;however,the time and pulp density were also noted.As the fitted RFR failed to satisfactorily predict leaching efficiencies in additional validation experiments,we recommend increasing the number of ex-periments and using additional fitting models.An additional analysis that included the initial oxidation-reduction potential(optimal 33.3 mV)revealed this to be the most important variable,the effect of which largely overshadows those of all the other variables.Finally,an environmental assessment highlighted the benefits of the chelating extraction;however,the economic assessment indicated room for improvement.展开更多
Coating-free press-hardened steel(CF-PHS)had effectively tackled the challenge of high-temperature oxidation during processing through Cr-Si alloying strategy.However,it is equally essential to investigate its corrosi...Coating-free press-hardened steel(CF-PHS)had effectively tackled the challenge of high-temperature oxidation during processing through Cr-Si alloying strategy.However,it is equally essential to investigate its corrosion resistance and the role of the oxide scale in corrosion environments.The corrosion resistance of CF-PHS with and without oxide scale was comprehensively evaluated by analyzing electrochemical processes and corrosion products,as well as characterizing the corroded oxide scale features,while comparing it with commercial 22MnB5 steel.The results indicate that CF-PHS exhibits superior corrosion resistance compared to 22MnB5 steel and the presence of oxide scale may have a negative influence on short-time corrosion resistance.The ultra-thin oxide scale is unable to effectively and timely mitigate pit propagation during the rapid electrochemical tests.Conversely,during the prolonged corrosion process,the oxide scale can still function as the physical barrier to provide protective effects,making the corrosion process develop more slowly and evenly.展开更多
Nitric oxide(NO)is a key vasodilator that regulates vascular pressure and blood flow.Tibetans have developed a"blunted"mechanism for regulating NO levels at high altitude,with GTP cyclohydrolase 1(GCH1)ident...Nitric oxide(NO)is a key vasodilator that regulates vascular pressure and blood flow.Tibetans have developed a"blunted"mechanism for regulating NO levels at high altitude,with GTP cyclohydrolase 1(GCH1)identified as a key candidate gene.Here,we present comprehensive genetic and functional analyses of GCH1,which exhibits strong Darwinian positive selection in Tibetans.We show that Tibetan-enriched GCH1 variants down-regulate its expression in the blood of Tibetans.Based on this observation,we generate the heterozygous Gch1 knockout(Gch1^(+/-))mouse model to simulate its downregulation in Tibetans.We find that under prolonged hypoxia,the Gch1^(+/-)mice have relatively higher blood NO and blood oxygen saturation levels compared with the wild-type(WT)controls,providing better oxygen supplies to the cardiovascular and pulmonary systems.Markedly,hypoxia-induced cardiac hypertrophy and pulmonary remodeling are significantly attenuated in the Gch1^(^(+/-))mice compared with the WT controls,likely due to the adaptive changes in molecular regulations related to metabolism,inflammation,circadian rhythm,extracellular matrix,and oxidative stress.This study sheds light on the role of GCH1 in regulating blood NO,contributing to the physiological adaptation of the cardiovascular and pulmonary systems in Tibetans at high altitude.展开更多
High-entropy oxides(HEOs)have emerged as a promising class of memristive materials,characterized by entropy-stabilized crystal structures,multivalent cation coordination,and tunable defect landscapes.These intrinsic f...High-entropy oxides(HEOs)have emerged as a promising class of memristive materials,characterized by entropy-stabilized crystal structures,multivalent cation coordination,and tunable defect landscapes.These intrinsic features enable forming-free resistive switching,multilevel conductance modulation,and synaptic plasticity,making HEOs attractive for neuromorphic computing.This review outlines recent progress in HEO-based memristors across materials engineering,switching mechanisms,and synaptic emulation.Particular attention is given to vacancy migration,phase transitions,and valence-state dynamics—mechanisms that underlie the switching behaviors observed in both amorphous and crystalline systems.Their relevance to neuromorphic functions such as short-term plasticity and spike-timing-dependent learning is also examined.While encouraging results have been achieved at the device level,challenges remain in conductance precision,variability control,and scalable integration.Addressing these demands a concerted effort across materials design,interface optimization,and task-aware modeling.With such integration,HEO memristors offer a compelling pathway toward energy-efficient and adaptable brain-inspired electronics.展开更多
Improving device efficiency is fundamental for advancing energy harvesting technology,particularly in systems designed to convert light energy into electrical output.In our previous studies,we developed a basic struct...Improving device efficiency is fundamental for advancing energy harvesting technology,particularly in systems designed to convert light energy into electrical output.In our previous studies,we developed a basic structure light pressure electric generator(Basic-LPEG),which utilized a layered configuration of Ag/Pb(Zr,Ti)O_(3)(PZT)/Pt/GaAs to generate electricity based on light-induced pressure on the PZT.In this study,we sought to enhance the performance of this Basic-LPEG by introducing Ag nanoparticles/graphene oxide(AgNPs/GO)composite units(NP-LPEG),creating upgraded harvesting device.Specifically,by depositing the AgNPs/GO units twice onto the Basic-LPEG,we observed an increase in output voltage and current from 241 mV and 3.1μA to 310 mV and 9.3μA,respectively,under a solar simulator.The increase in electrical output directly correlated with the intensity of the light pressure impacting the PZT,as well as matched the Raman measurements,finite-difference time-domain simulations,and COMSOL Multiphysics Simulation.Experimental data revealed that the enhancement in electrical output was proportional to the number of hot spots generated between Ag nanoparticles,where the electric field experienced substantial amplification.These results underline the effectiveness of AgNPs/GO units in boosting the light-induced electric generation capacity,thereby providing a promising pathway for high-efficiency energy harvesting devices.展开更多
The production of vanadium-titanium magnetite(VTM)pellets has the problems of low consolidation strength and high energy consumption in the preheating and roasting process.High-pressure grinding roll(HPGR)pretreatment...The production of vanadium-titanium magnetite(VTM)pellets has the problems of low consolidation strength and high energy consumption in the preheating and roasting process.High-pressure grinding roll(HPGR)pretreatment process was used to increase the fine-grained content and specific surface area of VTM concentrates,to strengthen the oxidation consolidation process of VTM pellets,and oxidation kinetic experiments were carried out.The results showed that the specific surface area of VTM concentrates was increased from 872 to 1457 cm^(2)/g by HPGR and then pelletising and roasting.With preheating at 1000℃ for 10 min and roasting at 1260℃ for 10 min,the strengths of preheated pellets were increased from 329 to 535 N,and the strengths of roasted pellets were increased from 1010 to 2591 N.The limiting link in the early stage of VTM pellets oxidation was the control of chemical reaction,while the limiting link in the later stage of oxidation was the mixed control of chemical reaction and gas diffusion.The activation energies of VTM pellets before and after HPGR pretreatment were 53.07 and 40.03 kJ/mol in the early stage of oxidation reaction,while the activation energies in the later stage of oxidation were 29.24 and 22.75 kJ/mol,respectively.展开更多
Carbon coatings for silicon(Si)-based anode materials are essential for designing high-performance Li-ion batteries(LIBs).The coatings prevent direct contact with the electrolyte and enhance anode performance.However,...Carbon coatings for silicon(Si)-based anode materials are essential for designing high-performance Li-ion batteries(LIBs).The coatings prevent direct contact with the electrolyte and enhance anode performance.However,conventional carbon coatings are limited by their volume expansion and structural degradation,which lead to capacity fading and reduced durability.This study introduces a scalable and practical one-step carbon-coating strategy for directly coating silicon suboxide(SiO_(x))-based materials using aqueous quasi-defect-free reduced graphene oxide(QrGO)without post-treatment,unlike conventional graphene oxide(GO)-based coating methods.This simple process enables uniform encapsulation with QrGO for a highly adhesive and conductive coating.The QrGO-based composite anode material has several advantages,including reduced cracking due to volume expansion and enhanced charge carrier transport,as well as an increased Si content of 20 wt.%compared to the 5 wt.%in typical commercial Si-based active materials.In particular,the capacity retention of the QrGO-coated Si electrodes dramatically increases at high C-rate.The full cell exhibited long-term stability and capacity that were twice that of commercial SiO_(x)-based cells.Therefore,the QrGO-based one-step coating process represents a scalable,transformative,and commercially viable strategy for developing high-performance LIBs.展开更多
Poly(phenylene oxide)(PPO)exhibits excellent dielectric properties,making it an ideal substrate for high-frequency,high-speed copper-clad laminates.The phenolic hydroxyl group at the end of PPO plays a key role in its...Poly(phenylene oxide)(PPO)exhibits excellent dielectric properties,making it an ideal substrate for high-frequency,high-speed copper-clad laminates.The phenolic hydroxyl group at the end of PPO plays a key role in its reactivity.Accurately quantifying the phenolic hydroxyl content in PPO is essential but challenging.In this study,we proposed a method for measuring the phenolic hydroxyl content of PPO using differential UV absorption spectroscopy.In alkaline solutions,the phenolic hydroxyl in PPO completely ionizes to form phenoxide ions,leading to a significant increase in UV absorbance at approximately 250 and 300 nm.Notably,the differential UV absorbance at approximately 300 nm was directly proportional to the phenolic hydroxyl concentration.Using 2,6-dimethylphenol as a standard,a calibration curve was established to relate the phenolic hydroxyl concentration to differential UV absorbance at approximately 300 nm,providing a precise and straightforward method for phenolic hydroxyl quantification in PPO with distinct advantages over conventional techniques.展开更多
This study explored the impact of sintering time and temperature on the synthesis and formation of high-entropy rare earth oxides(HEOs).By systematically varying the sintering conditions,a series of Lu_(2)Yb_(2)Tm_(2)...This study explored the impact of sintering time and temperature on the synthesis and formation of high-entropy rare earth oxides(HEOs).By systematically varying the sintering conditions,a series of Lu_(2)Yb_(2)Tm_(2)Er_(2)O_(12) samples was synthesized and their structural and chemical properties were analyzed using scanning electron microscopy(SEM)with energy-dispersive X-ray spectroscopy(EDS)elemental mapping,X-ray diffraction(XRD),high-resolution transmission electron microscopy(HRTEM),and X-ray photoelectron spectroscopy(XPS).According to XRD patterns,a single-phase cubic C-type structure is easier to form at higher sintering temperatures(1400-1500℃),with sharper peaks signifying better crystallinity.With longer sintering times improving grain development and homogeneity,SEM research reveals a change in morphology from spherical grains at lower temperatures(1100-1200℃)to blocky grains at higher temperatures(1300-1500℃).HRTEM pictures verified the nanoparticles'strong crystallinity,and at higher temperatures,the lattice fringes widen and become more distinct,indicating better atomic ordering and diffusion.Stable and uniform high-entropy oxide production is indicated by the XPS spectra,which shows uniform elemental distribution and consistent chemical states of the constituent elements with very slight variations in the oxygen peaks.The findings highlight how important the sintering temperature is for reaching the intended high-entropy phase,with higher temperatures promoting improved atomic diffusion and compositional homogeneity.The results open the door for the use of high-entropy rare earth oxides in sophisticated functional materials by offering insightful information on how to best synthesize them.展开更多
Magnetic resonance imaging(MRI)is one of the most widely used diagnostic techniques.Iron oxide nanoparticles,as a promising kind of contrast agents,have attracted intense research interest due to their low toxicity an...Magnetic resonance imaging(MRI)is one of the most widely used diagnostic techniques.Iron oxide nanoparticles,as a promising kind of contrast agents,have attracted intense research interest due to their low toxicity and superparamagnetism.However,it is still a great challenge to prepare ideal iron oxide based contrast agents with high uniformity,excellent water solubility and biocompatibility.In this paper,a novel water-soluble polymer ligand pentaerythritol tetrakis 3-mercaptopropionate-poly(N-vinyl-2-pyrrolidone)(PTMP-PVP)was used as a capping reagent to prepare iron oxide nanoparticles MIONs@PTMP-PVP through one-step co-precipitation of iron precursors in aqueous solution at 100℃.The obtained nanoparticles MIONs@PTMP-PVP had a small size and narrow size distribution,and they were found to be biocompatible as determined through CCK-8 assay and histology analysis.In vivo MRI study demonstrated that the obtained MIONs@PTMP-PVP can be potentially used as an effective T_(2)-weighted MRI contrast agent.展开更多
We employed oxygen plasma treatment to activate the PTFE surface and introduce oxygencontaining polar groups(-OH,C-O,C=O),thereby enhancing surface energy and interfacial reactivity.We subsequently composited the modi...We employed oxygen plasma treatment to activate the PTFE surface and introduce oxygencontaining polar groups(-OH,C-O,C=O),thereby enhancing surface energy and interfacial reactivity.We subsequently composited the modified PTFE(PTFE-O)with graphene oxide(GO),enabling tight interactions between the two phases through hydrogen bonding and van der Waals forces.Comprehensive characterizations,including XPS,FTIR,SEM,and contact angle analysis,confirmed the successful surface modification and uniform dispersion of GO.The optimized PTFE-O/GO composite exhibits a low resistivity of 2.41×10^(3)Ω·cm under a compression pressure of 2 MPa,demonstrating markedly improved conductivity and antistatic performance.These findings provide an effective route for constructing conductive PTFE-based composites and offer new insights into interface-engineered antistatic polymer materials.展开更多
Sodium layered oxides stand out as one of the most promising cathodes for sodium-ion batteries due to their high energy density,elemental abundance,and scalability.However,their practical applications are restricted b...Sodium layered oxides stand out as one of the most promising cathodes for sodium-ion batteries due to their high energy density,elemental abundance,and scalability.However,their practical applications are restricted by interplanar gliding,cation migration,and the formation of intragranular microcracks,which collectively lead to rapid structural degradation and capacity loss.Herein,we rationally design an ultrastable O3-type Na_(0.94)Ca_(0.03)Ni_(1/3)Fe_(1/3)Mn_(1/3)O_(2) cathode,in which Ca^(2+)cations act as pillars within the NaO_(2)slabs,suppressing the irreversible phase transitions and Na/TM cation migration commonly observed in layered oxides.Multiscale in situ and ex situ techniques,combined with post-mortem analysis,reveal that the Ca-pillared pinning effect not only effectively suppresses the interplanar gliding and stress accumulation within the crystal phase but also restrains Na/TM cation migration and surface reconstruction in near-surface regions.Benefiting from the combined effects of structural stabilization,the Ca-pillared cathode exhibits a superior cycling stability,retaining 81.6%of its capacity after 1000 cycles at 2 C within the voltage range of 2.0-4.0 V,along with significantly enhanced wide-temperature(from-40 to 80℃)performance.This work highlights another critical role of Ca pillars in suppressing cation migration and surface structural degradation beyond preventing adverse interplanar gliding,offering valuable insights for designing long-life and wide-temperature layered oxide cathodes.展开更多
High-capacity O3-type layered NiFeMn-based oxides are promising cathodes for sodium-ion batteries,though their practical deployment is constrained by the inherent limitations of Fe redox chemistry.Traditional designs ...High-capacity O3-type layered NiFeMn-based oxides are promising cathodes for sodium-ion batteries,though their practical deployment is constrained by the inherent limitations of Fe redox chemistry.Traditional designs generally enforcing stoichiometric symmetry(Ni=Mn)yield low Fe redox activity.Herein,we propose a valence engineering strategy that breaks conventional Ni/Mn stoichiometry to reconfigure Fe's local chemical environment and unlock unprecedented redox depth.Density functional theory(DFT)calculations reveal that the designed NaNi_(0.35)Fe_(0.225)Mn_(0.425)O_(2)cathode exhibits a reduced Bader charge on Fe(1.598 vs.1.638 in NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2))and elevated Fe 3d orbital energy,signifying enhanced Fe redox activity.This configuration enables an exceptional Fe^(2.60+)/Fe^(3.88+)redox(1.28 e~-per Fe),delivering a reversible capacity of184.3 mAh g^(-1)within 2-4.2 V at 0.2 C,markedly exceeding the benchmark NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(161.3 mAh g^(-1))with low reaction depth of Fe^(3.01+)/Fe^(3.61+).The intensified cationic redox reaction enables an ultrahigh energy density of 596 Whkg-1.The NaNi_(0.35)Fe_(0.225)Mn_(0.425)O_(2)cathode demonstrates robust performance over a broad temperature range from-15℃to 60℃.In situ and ex situ characterizations unveil a reversible O3■P3■OP2 phase transition with minimal volume change(1.88%)that circumvents detrimental deleterious O'3 intermediates and intragranular cracking.This work establishes valence engineering as a paradigm to consolidate cationic redox reaction in high-energy layered sodium oxide cathodes.展开更多
基金supported by the National Natural Science Foundation of China(51373137)the International cooperation project of Shaanxi Province(2016KW-053)the Natural Science Basic Research Plan in Shaanxi(2017JQ2002)
文摘A novel graphene oxide/titanium dioxide（GO/TiO2） solvent-free nanofluid was firstly synthesized by employing GO, which was in-situ deposited by TiO2 as the core and（3-Glycidyloxypropyl） trime thoxysilane（KH560） and polyetheramine-M2070 as the shell. The morphology and structure of GO/TiO2 nanofluid were verified by Transmission electron microscopy（TEM）, X-ray diffraction（XRD） analysis, Fourier transform infrared spectroscopy（FTIR）, X-ray photoelectron spectroscopy（XPS） and UV-vis absorption spectra. These studies confirmed that TiO2 has been deposited onto GO with good dispersion, and the organic shell has been grafted onto the core successfully. Thermo gravimetric analysis（TGA） and viscosity analysis indicated that this nanoparticle hybrid material presented a liquid state without solvent at room temperature, and has great fluidity and thermal stability. The solubility investigation of GO/TiO2 nanofluid revealed its excellent amphiphilicity and the potential as the functional nanocomposites.
基金supported by the Universiti Brunei Darussalam Research Funding(Grant No.UBD/OAVCRI/CRGWG(022)/171001).
文摘Three-dimensional(3D)porous absorbents have attracted significant attention in the oily wastewater treatment technology due to their high porosity and elasticity.Given their amphiphilic surface,they have a propensity to simultaneously absorb water and oil,which restricts their range of applications.In this study,a reduced graphene oxide and titanium dioxide nanocomposite(rGO/TiO_(2))was used to fabricate an ultra-hydrophobic melamine sponge(MS)through interfacial modification using a solution immersion technique.To further modify it,poly-dimethylsiloxane(PDMS)was grafted onto its surface to establish stronger covalent bonds with the composite.The water contact angle of the sponge(rGO/TiO_(2)/PDMS/MS)was 164.2°,which satisfies the condition for ultrahydrophobicity.The evidence of its water repellency was demonstrated by the Cassie-Baxter theory and the lotus leaf effect.As a result of the increased density of rGO/TiO_(2)/PDMS/MS,it recorded an initial capacity that was 2 g/g lower than the raw MS for crude oil absorption.The raw MS retained 53% of its initial absorption capacity after 20 cycles of absorption,while rGO/TiO_(2)/PDMS/MS retained 97%,suggesting good recyclability.Excellent oil and organic solvent recovery(90%-96%)was demonstrated by rGO/TiO_(2)/PDMS/MS in oil-water combinations.In a continuous separation system,it achieved a remarkable separation efficiency of 2.4×10^(6)L/(m^(3)·h),and in turbulent emulsion separation,it achieved a demulsification efficiency of 90%-91%.This study provides a practical substitute for massive oil spill cleaning.
基金The authors gratefully acknowledge the research assistance of Wei Qiu and the University of Auckland Summer Research Scholarship for Mona LiuThe authors are also thankful to Higher Education Commission,Pakistan for scholarship grant for one of authors,Dr.Surayya Mukhtar for this research work.
文摘A stable and insoluble V2O5·n H2O/tetra-n-butyl titanate（TBO） hybrid xerogel was synthesized by the sol–gel method. This novel material proved to be an efficient absorbent with an absorption capacity of 179 mg·g^-1for Rhodamine B（Rh B） in water due to its unique layered structure, which can effectively accommodate Rh B molecules between its layers as demonstrated by XRD and FTIR spectroscopic analyses.
基金supported by the National Natural Science Foundation of China(Nos.81974441 and 82203619)the Science and Technology Planning Project of Shenzhen Municipality(Nos.JCYJ20190814105619048 and JCYJ20220530154202005)。
文摘Colitis-associated colorectal cancer(CAC)is a major contributor to cancer-related mortality worldwide.Titanium dioxide(TiO_(2),E171),a widely used food additive,has been insufficiently studied regarding its effects on macrophages within colon tumors during CAC development.In this study,CAC mouse models were used to investigate the biological impact of dietary E171 on macrophages in vivo,while lipopolysaccharide(LPS)-stimulated RAW264.7 macrophage cell lines were employed to elucidate the underlying mechanisms in vitro.We found that dietary E171 intake accelerated CAC development,exacerbated inflammatory responses and oxidative stress,and upregulated CAC-associated genes,including S100a8,S100a9,Lcn2,S100a11,Cxcl2,and interleukin-1α(Il-1α).E171 also increased the expression of S100A8,S100A9,NOD-like receptor family pyrin domain-containing 3(NLRP3),and gasdermin-D Nterminal(GSDMD-N)in macrophages within colon tumors.In inflammatory macrophages,E171 exposure enhanced cell viability,increased reactive oxygen species(ROS)levels,and elevated the expression and secretion of S100A8 and S100A9,consistent with in vivo histological observations.Furthermore,E171-induced secretion of S100A8 and S100A9 in macrophages was suppressed by specific inhibitors,including N-acetylcysteine(NAC,ROS inhibitor),MCC950(NLRP3 inhibitor),Z-YVAD-FMK(caspase 1 inhibitor),disulfiram(GSDMD inhibitor),and transfection of NLRP3 small interfering ribonucleic acid(siRNA).These results indicate that dietary E171 promotes CAC development by activating macrophages,with S100A8 and S100A9 serving as key mediators,and the NLRP3/caspase 1/GSDMD pathway acting as a critical mechanism.
基金Supported by the Natural Science Foundation of Shanxi Province(202203021221303)the Science and Technology Major Project of Shanxi Province(202005D121002)the Science and Technology Cooperation and Communication Project of Shanxi Province(202304041101016)。
文摘Propylene oxide(PO)is an important petrochemical materials used to produce downstream products such as propylene glycol(PG),polyether polyols,and dipropylene glycol(DPG).Among these,DPG is commonly used as a solvent for fragrances,cosmetics,food additives,and detergents,and can also be served as a moisturizer in cosmetics,showing broad application prospects.The distribution of DPG isomers in the products synthesized from PO and PG has a significant impactΔrGΔrHΔfHθΔfGθPO+PG⇌DPG PO+DPG⇌TPG PG+PG⇌DPG+H_(2)O PG+DPG⇌TPG+H_(2)O on the quality of the products.Therefore,conducting thermodynamic calculation on the reaction of PO and PG to synthesize DPG can provide a theoretical basis for practical operations and product distribution regulation.So,in this paper,the thermodynamic parameters of PO,1,2-PG,H_(2)O,tripropylene glycol(TPG)and three isomers of DPG under different reaction conditions is calculated.Additionally,the,and lnK for four potential reactions at various reaction temperatures and pressures are calculated.By designing isodesmic reactions and combining the results of thermodynamic calculations,the and for the isomers of DPG are obtained,and the relative error is less than 7%.The results show that in the process of preparing DPG by PO and PG,when PO∶PG=1,the reaction temperature ranges from 298.15 to 413.15 K,and the pressure ranges from 101.325 to 506.625 kPa,the reactions of and are thermodynamically spontaneous.While the reactions of and are thermodynamically unspontaneous.The optimal reaction temperature and pressure are 413.15 K and 101.325 kPa.The thermodynamic stability of the three isomers is DPG1>DPG2>DPG3 under standard conditions.The accuracy of the computational results is verified through experimental design,and based on this,the factors affecting product distribution are analyzed.
文摘Black nickel coatings have emerged as a research hotspot in materials science due to their excellent performance and broad application prospects.In this study,nickel-based black coatings were fabricated on low-carbon steel substrates via photo-assisted electrodeposition.A systematic investigation was conducted on the effects of cerium ion concentration and nano-ceria(CeO_(2))particle content in the electrolyte on the coating properties,along with an analysis of the temporal evolution of coating’s corrosion resistance.When the cerium ion concentration in the electrolyte was 0.05 mol/L,the coating exhibited a uniform black appearance with a light absorption rate of 95%,an emissivity of 0.87,maximum impedance,and the lowest corrosion tendency,demonstrating optimal comprehensive performance.The coating prepared with a nano-ceria concentration of 6 g/L in the electrolyte exhibited an emissivity of 0.9,achieved a 5B adhesion grade(ASTM D3359-09),and demonstrated a one-order-of-magnitude reduction in corrosion current density compared to coatings fabricated without nano-ceria in the electrolyte.With prolonged storage time,the coating's impedance slightly increased,leading to improved corrosion resistance.
文摘It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions(<400℃).In this work,five Fe-Ce-La oxides were prepared by co-precipitation method,and FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbents were prepared by coupling fly ash-based Si-Al carriers.The active components Fe-Ce-La oxides and Si-Al carriers were characterized by TPD,TG,XRF,BET and XPS,respectively.The effects of temperature,Si/Al ratio and FeCeLaO loading rate on the sulfur resistance were investigated.Results show that the SO_(2) promotes the arsenic removal of Fe_(2)O_(3),CeLaO and FeCeLaO.At 400℃,the arsenic removal efficiencies of the three oxides increase from 45.3%,72.5% and 81.3% without SO_(2) to 62.6%,80.5%and 91.0%,respectively.The SO_(2) inhibits the arsenic removal of La_(2)O_(2)CO_(3) and FeLaO,and the inhibition effect is pronounced at high temperatures.The sulfur poisoning resistance of Si-Al carriers increases with the increase of Si/Al ratio.When the Si/Al ratio is increased to 9.74,the arsenic removal efficiency in the SO_(2) environment is 13.9% higher than that in the absence of SO_(2).Introducing FeCeLaO active components is beneficial for enhancing the SO_(2) poisoning resistance of Si-Al carriers.The strong sulfur resistance of the FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbent results from multiple factors:protective effects of Ce on Fe,La and Al;sulfation-induced generation of Ce^(3+)and surface-adsorbed oxygen;and strong surface acidity of SiO_(2).
基金supported by the National Research Foundation of Korea(NRF)grants funded by the Korea government(MSIT)(Nos.RS-2024-00406500 and RS-2024-00458682).
文摘Lithium-ion batteries(LIBs)that reached their end-of-life(EoL)require recycling,rather than disposal,to recirculate valuable metals and protect the environment.This led us to investigate the extraction of metals from the cathodes of EoL lithium-titanate batteries using ethylenediaminetetraacetic acid disodium(EDTA-2Na).In this work,an orthogonal array was used to design experiments and sig-nal-to-noise calculations were used to define the optimal conditions,which were 0.50 mol/L EDTA-2Na,pH=6,75℃,180 min,2%pulp density,and 300 r/min,resulting in 97.96%,94.79%,96.45%,and 98.89%leaching efficiencies for Li,Ni,Co,and Mn,respectively.Stat-istically significant interactions between variables were then identified using Pearson’s correlation at the 95%confidence interval,and the pH and temperature were found to be significant.The extraction efficiency decreased as the pH increased,but increased as the temperat-ure increased.Machine learning fitting using linear regression for multi-output prediction was unsatisfactory,whereas random forest re-gression(RFR)produced satisfactory results.Permutation importance was computed on the fitted RFR to determine feature importance,and confirmed that the pH and temperature were influential variables;however,the time and pulp density were also noted.As the fitted RFR failed to satisfactorily predict leaching efficiencies in additional validation experiments,we recommend increasing the number of ex-periments and using additional fitting models.An additional analysis that included the initial oxidation-reduction potential(optimal 33.3 mV)revealed this to be the most important variable,the effect of which largely overshadows those of all the other variables.Finally,an environmental assessment highlighted the benefits of the chelating extraction;however,the economic assessment indicated room for improvement.
基金supported by the National Natural Science Foundation of China(Grant Nos.U22A20106,52201112,and U22A20173)Fundamental Research Funds for the Central Universities(N25LJ002).
文摘Coating-free press-hardened steel(CF-PHS)had effectively tackled the challenge of high-temperature oxidation during processing through Cr-Si alloying strategy.However,it is equally essential to investigate its corrosion resistance and the role of the oxide scale in corrosion environments.The corrosion resistance of CF-PHS with and without oxide scale was comprehensively evaluated by analyzing electrochemical processes and corrosion products,as well as characterizing the corroded oxide scale features,while comparing it with commercial 22MnB5 steel.The results indicate that CF-PHS exhibits superior corrosion resistance compared to 22MnB5 steel and the presence of oxide scale may have a negative influence on short-time corrosion resistance.The ultra-thin oxide scale is unable to effectively and timely mitigate pit propagation during the rapid electrochemical tests.Conversely,during the prolonged corrosion process,the oxide scale can still function as the physical barrier to provide protective effects,making the corrosion process develop more slowly and evenly.
基金funded by grants from the National Natural Science Foundation of China(32288101 and 91631306 to B.S32170632 and 32000390 to Y.H.32400503 to Y.G.)Major Scientific Project of Yunnan Province(202305AH340007 to B.S.)+4 种基金Yunnan Revitalization Talent Support Program Science&Technology Champion Project(202005AB160004 to B.S.)Yunnan Revitalization Talent Support Program Innovation Team(202405AS350008)Yunnan Scientist Workshops(to B.S.)the Youth Innovation Promotion Association of CAS(to Y.H.),the Science and Technology General Program of Yunnan Province(202301AW070010 and 202001AT070110 to Y.H.)and the Provincial Key Research,Development,and Translational Program(XZ202101ZY0009G to Baima.).
文摘Nitric oxide(NO)is a key vasodilator that regulates vascular pressure and blood flow.Tibetans have developed a"blunted"mechanism for regulating NO levels at high altitude,with GTP cyclohydrolase 1(GCH1)identified as a key candidate gene.Here,we present comprehensive genetic and functional analyses of GCH1,which exhibits strong Darwinian positive selection in Tibetans.We show that Tibetan-enriched GCH1 variants down-regulate its expression in the blood of Tibetans.Based on this observation,we generate the heterozygous Gch1 knockout(Gch1^(+/-))mouse model to simulate its downregulation in Tibetans.We find that under prolonged hypoxia,the Gch1^(+/-)mice have relatively higher blood NO and blood oxygen saturation levels compared with the wild-type(WT)controls,providing better oxygen supplies to the cardiovascular and pulmonary systems.Markedly,hypoxia-induced cardiac hypertrophy and pulmonary remodeling are significantly attenuated in the Gch1^(^(+/-))mice compared with the WT controls,likely due to the adaptive changes in molecular regulations related to metabolism,inflammation,circadian rhythm,extracellular matrix,and oxidative stress.This study sheds light on the role of GCH1 in regulating blood NO,contributing to the physiological adaptation of the cardiovascular and pulmonary systems in Tibetans at high altitude.
基金financially supported by the National Natural Science Foundation of China(Grant No.12172093)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2021A1515012607)。
文摘High-entropy oxides(HEOs)have emerged as a promising class of memristive materials,characterized by entropy-stabilized crystal structures,multivalent cation coordination,and tunable defect landscapes.These intrinsic features enable forming-free resistive switching,multilevel conductance modulation,and synaptic plasticity,making HEOs attractive for neuromorphic computing.This review outlines recent progress in HEO-based memristors across materials engineering,switching mechanisms,and synaptic emulation.Particular attention is given to vacancy migration,phase transitions,and valence-state dynamics—mechanisms that underlie the switching behaviors observed in both amorphous and crystalline systems.Their relevance to neuromorphic functions such as short-term plasticity and spike-timing-dependent learning is also examined.While encouraging results have been achieved at the device level,challenges remain in conductance precision,variability control,and scalable integration.Addressing these demands a concerted effort across materials design,interface optimization,and task-aware modeling.With such integration,HEO memristors offer a compelling pathway toward energy-efficient and adaptable brain-inspired electronics.
基金supported by Korea Evaluation Institute of Industrial Technology(KEIT)grant funded by the Korea Government(MOTIE)(RS-2022-00154720,Technology Innovation Program Development of next-generation power semiconductor based on Si-on-SiC structure)the National Research Foundation of Korea(NRF)by the Korea government(RS-2023-NR076826)Global-Learning&Academic Research Institution for Master's·PhD students,and Postdocs(LAMP)Program of the National Research Foundation of Korea(NRF)by the Ministry of Education(No.RS-2024-00443714).
文摘Improving device efficiency is fundamental for advancing energy harvesting technology,particularly in systems designed to convert light energy into electrical output.In our previous studies,we developed a basic structure light pressure electric generator(Basic-LPEG),which utilized a layered configuration of Ag/Pb(Zr,Ti)O_(3)(PZT)/Pt/GaAs to generate electricity based on light-induced pressure on the PZT.In this study,we sought to enhance the performance of this Basic-LPEG by introducing Ag nanoparticles/graphene oxide(AgNPs/GO)composite units(NP-LPEG),creating upgraded harvesting device.Specifically,by depositing the AgNPs/GO units twice onto the Basic-LPEG,we observed an increase in output voltage and current from 241 mV and 3.1μA to 310 mV and 9.3μA,respectively,under a solar simulator.The increase in electrical output directly correlated with the intensity of the light pressure impacting the PZT,as well as matched the Raman measurements,finite-difference time-domain simulations,and COMSOL Multiphysics Simulation.Experimental data revealed that the enhancement in electrical output was proportional to the number of hot spots generated between Ag nanoparticles,where the electric field experienced substantial amplification.These results underline the effectiveness of AgNPs/GO units in boosting the light-induced electric generation capacity,thereby providing a promising pathway for high-efficiency energy harvesting devices.
基金supports provided from Guangxi Science and Technology Major Project(AA24263047).
文摘The production of vanadium-titanium magnetite(VTM)pellets has the problems of low consolidation strength and high energy consumption in the preheating and roasting process.High-pressure grinding roll(HPGR)pretreatment process was used to increase the fine-grained content and specific surface area of VTM concentrates,to strengthen the oxidation consolidation process of VTM pellets,and oxidation kinetic experiments were carried out.The results showed that the specific surface area of VTM concentrates was increased from 872 to 1457 cm^(2)/g by HPGR and then pelletising and roasting.With preheating at 1000℃ for 10 min and roasting at 1260℃ for 10 min,the strengths of preheated pellets were increased from 329 to 535 N,and the strengths of roasted pellets were increased from 1010 to 2591 N.The limiting link in the early stage of VTM pellets oxidation was the control of chemical reaction,while the limiting link in the later stage of oxidation was the mixed control of chemical reaction and gas diffusion.The activation energies of VTM pellets before and after HPGR pretreatment were 53.07 and 40.03 kJ/mol in the early stage of oxidation reaction,while the activation energies in the later stage of oxidation were 29.24 and 22.75 kJ/mol,respectively.
基金supported by Korea Electrotechnology Research Institute(KERI)Primary research program through the National Research Council of Science&Technology(NST)funded by the Ministry of Science and ICT(MSIT)(No.25A01015)by the Technology Innovation Program(20019091)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)by the National Research Council of Science&Technology(NST)grant from the Korea government(MSIT)(No.GTL24012-000).
文摘Carbon coatings for silicon(Si)-based anode materials are essential for designing high-performance Li-ion batteries(LIBs).The coatings prevent direct contact with the electrolyte and enhance anode performance.However,conventional carbon coatings are limited by their volume expansion and structural degradation,which lead to capacity fading and reduced durability.This study introduces a scalable and practical one-step carbon-coating strategy for directly coating silicon suboxide(SiO_(x))-based materials using aqueous quasi-defect-free reduced graphene oxide(QrGO)without post-treatment,unlike conventional graphene oxide(GO)-based coating methods.This simple process enables uniform encapsulation with QrGO for a highly adhesive and conductive coating.The QrGO-based composite anode material has several advantages,including reduced cracking due to volume expansion and enhanced charge carrier transport,as well as an increased Si content of 20 wt.%compared to the 5 wt.%in typical commercial Si-based active materials.In particular,the capacity retention of the QrGO-coated Si electrodes dramatically increases at high C-rate.The full cell exhibited long-term stability and capacity that were twice that of commercial SiO_(x)-based cells.Therefore,the QrGO-based one-step coating process represents a scalable,transformative,and commercially viable strategy for developing high-performance LIBs.
基金the“Pioneer”and“Leading Goose”R&D Program of Zhejiang(No.2023C01072)the Institute of Zhejiang University-Quzhou for their financial support。
文摘Poly(phenylene oxide)(PPO)exhibits excellent dielectric properties,making it an ideal substrate for high-frequency,high-speed copper-clad laminates.The phenolic hydroxyl group at the end of PPO plays a key role in its reactivity.Accurately quantifying the phenolic hydroxyl content in PPO is essential but challenging.In this study,we proposed a method for measuring the phenolic hydroxyl content of PPO using differential UV absorption spectroscopy.In alkaline solutions,the phenolic hydroxyl in PPO completely ionizes to form phenoxide ions,leading to a significant increase in UV absorbance at approximately 250 and 300 nm.Notably,the differential UV absorbance at approximately 300 nm was directly proportional to the phenolic hydroxyl concentration.Using 2,6-dimethylphenol as a standard,a calibration curve was established to relate the phenolic hydroxyl concentration to differential UV absorbance at approximately 300 nm,providing a precise and straightforward method for phenolic hydroxyl quantification in PPO with distinct advantages over conventional techniques.
基金Project supported by Natural Science Foundation of Zhejiang Province(LD21E080001)Zhejiang Provincial Ten Thousand Talent Program(ZJWR0302055)。
文摘This study explored the impact of sintering time and temperature on the synthesis and formation of high-entropy rare earth oxides(HEOs).By systematically varying the sintering conditions,a series of Lu_(2)Yb_(2)Tm_(2)Er_(2)O_(12) samples was synthesized and their structural and chemical properties were analyzed using scanning electron microscopy(SEM)with energy-dispersive X-ray spectroscopy(EDS)elemental mapping,X-ray diffraction(XRD),high-resolution transmission electron microscopy(HRTEM),and X-ray photoelectron spectroscopy(XPS).According to XRD patterns,a single-phase cubic C-type structure is easier to form at higher sintering temperatures(1400-1500℃),with sharper peaks signifying better crystallinity.With longer sintering times improving grain development and homogeneity,SEM research reveals a change in morphology from spherical grains at lower temperatures(1100-1200℃)to blocky grains at higher temperatures(1300-1500℃).HRTEM pictures verified the nanoparticles'strong crystallinity,and at higher temperatures,the lattice fringes widen and become more distinct,indicating better atomic ordering and diffusion.Stable and uniform high-entropy oxide production is indicated by the XPS spectra,which shows uniform elemental distribution and consistent chemical states of the constituent elements with very slight variations in the oxygen peaks.The findings highlight how important the sintering temperature is for reaching the intended high-entropy phase,with higher temperatures promoting improved atomic diffusion and compositional homogeneity.The results open the door for the use of high-entropy rare earth oxides in sophisticated functional materials by offering insightful information on how to best synthesize them.
基金financially supported by the International Cooperation Program from the Ministry of Science and Technology of Hubei Province(No.2023EHA069)Shenzhen Science and Technology Program(No.JCYJ20230807143702005)National Foreign Experts Program(No.G2022027015L)。
文摘Magnetic resonance imaging(MRI)is one of the most widely used diagnostic techniques.Iron oxide nanoparticles,as a promising kind of contrast agents,have attracted intense research interest due to their low toxicity and superparamagnetism.However,it is still a great challenge to prepare ideal iron oxide based contrast agents with high uniformity,excellent water solubility and biocompatibility.In this paper,a novel water-soluble polymer ligand pentaerythritol tetrakis 3-mercaptopropionate-poly(N-vinyl-2-pyrrolidone)(PTMP-PVP)was used as a capping reagent to prepare iron oxide nanoparticles MIONs@PTMP-PVP through one-step co-precipitation of iron precursors in aqueous solution at 100℃.The obtained nanoparticles MIONs@PTMP-PVP had a small size and narrow size distribution,and they were found to be biocompatible as determined through CCK-8 assay and histology analysis.In vivo MRI study demonstrated that the obtained MIONs@PTMP-PVP can be potentially used as an effective T_(2)-weighted MRI contrast agent.
基金Funded by the Key Scientific and Technological Project of Zhejiang Provincial Administration for Market Regulation(No.ZD2024004)the National Natural Science Foundation of China(Nos.62304214 and 62304213)+2 种基金the Natural Science Foundation of Zhejiang Province(No.LQ23E020006)the Chunhui Project Foun-dation of the Education Department of China(No.HZKY20220198)the Fundamental Research Funds for the Provincial Universities of Zhejiang(Nos.2021YW35,2021YW36 and 2022YW62)。
文摘We employed oxygen plasma treatment to activate the PTFE surface and introduce oxygencontaining polar groups(-OH,C-O,C=O),thereby enhancing surface energy and interfacial reactivity.We subsequently composited the modified PTFE(PTFE-O)with graphene oxide(GO),enabling tight interactions between the two phases through hydrogen bonding and van der Waals forces.Comprehensive characterizations,including XPS,FTIR,SEM,and contact angle analysis,confirmed the successful surface modification and uniform dispersion of GO.The optimized PTFE-O/GO composite exhibits a low resistivity of 2.41×10^(3)Ω·cm under a compression pressure of 2 MPa,demonstrating markedly improved conductivity and antistatic performance.These findings provide an effective route for constructing conductive PTFE-based composites and offer new insights into interface-engineered antistatic polymer materials.
基金supported by the National Key R&D Program of China(2023YFB2406000)the National Natural Science Foundation of China(22479057,52172201,51732005)。
文摘Sodium layered oxides stand out as one of the most promising cathodes for sodium-ion batteries due to their high energy density,elemental abundance,and scalability.However,their practical applications are restricted by interplanar gliding,cation migration,and the formation of intragranular microcracks,which collectively lead to rapid structural degradation and capacity loss.Herein,we rationally design an ultrastable O3-type Na_(0.94)Ca_(0.03)Ni_(1/3)Fe_(1/3)Mn_(1/3)O_(2) cathode,in which Ca^(2+)cations act as pillars within the NaO_(2)slabs,suppressing the irreversible phase transitions and Na/TM cation migration commonly observed in layered oxides.Multiscale in situ and ex situ techniques,combined with post-mortem analysis,reveal that the Ca-pillared pinning effect not only effectively suppresses the interplanar gliding and stress accumulation within the crystal phase but also restrains Na/TM cation migration and surface reconstruction in near-surface regions.Benefiting from the combined effects of structural stabilization,the Ca-pillared cathode exhibits a superior cycling stability,retaining 81.6%of its capacity after 1000 cycles at 2 C within the voltage range of 2.0-4.0 V,along with significantly enhanced wide-temperature(from-40 to 80℃)performance.This work highlights another critical role of Ca pillars in suppressing cation migration and surface structural degradation beyond preventing adverse interplanar gliding,offering valuable insights for designing long-life and wide-temperature layered oxide cathodes.
基金supported by the National Natural Science Foundation of China(Grant Nos.52202282,52402054,22471283,and 52202327)Natural Science Foundation of Tianjin City(Grant Nos.22JCYBJC00040,24JCQNJC00970)。
文摘High-capacity O3-type layered NiFeMn-based oxides are promising cathodes for sodium-ion batteries,though their practical deployment is constrained by the inherent limitations of Fe redox chemistry.Traditional designs generally enforcing stoichiometric symmetry(Ni=Mn)yield low Fe redox activity.Herein,we propose a valence engineering strategy that breaks conventional Ni/Mn stoichiometry to reconfigure Fe's local chemical environment and unlock unprecedented redox depth.Density functional theory(DFT)calculations reveal that the designed NaNi_(0.35)Fe_(0.225)Mn_(0.425)O_(2)cathode exhibits a reduced Bader charge on Fe(1.598 vs.1.638 in NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2))and elevated Fe 3d orbital energy,signifying enhanced Fe redox activity.This configuration enables an exceptional Fe^(2.60+)/Fe^(3.88+)redox(1.28 e~-per Fe),delivering a reversible capacity of184.3 mAh g^(-1)within 2-4.2 V at 0.2 C,markedly exceeding the benchmark NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(161.3 mAh g^(-1))with low reaction depth of Fe^(3.01+)/Fe^(3.61+).The intensified cationic redox reaction enables an ultrahigh energy density of 596 Whkg-1.The NaNi_(0.35)Fe_(0.225)Mn_(0.425)O_(2)cathode demonstrates robust performance over a broad temperature range from-15℃to 60℃.In situ and ex situ characterizations unveil a reversible O3■P3■OP2 phase transition with minimal volume change(1.88%)that circumvents detrimental deleterious O'3 intermediates and intragranular cracking.This work establishes valence engineering as a paradigm to consolidate cationic redox reaction in high-energy layered sodium oxide cathodes.
