In recent years,renewable energy sources,which aim to replace rapidly depleting fossil fuels,face challenges due to limited energy storage and conversion technologies.To enhance energy storage and conversion efficienc...In recent years,renewable energy sources,which aim to replace rapidly depleting fossil fuels,face challenges due to limited energy storage and conversion technologies.To enhance energy storage and conversion efficiency,extensive research has been conducted in the academic community on numerous potential materials.Among these materials,metal fluorides have attracted significant attention due to their ionic metal-fluorine bonds and tunable electronic structures,attributed to the highest electronegativity of fluorine in their chemical composition.This makes them promising candidates for future electrochemical applications in various fields.However,metal fluorides encounter various challenges in different application directions.Therefore,we comprehensively review the applications of metal fluorides in the field of energy storage and conversion,aiming to deepen our understanding of their exhibited characteristics in different electrochemical processes.In this paper,we summarize the difficulties and improvement methods encountered in different types of battery applications and several typical electrode optimization strategies in the field of supercapacitors.In the field of water electrolysis,we focus on surface reconstruction and the critical role of fluorine,demonstrating the catalytic performance of metal fluorides from the perspectives of reconstruction mechanism and process analysis.Finally,we provide a summary and outlook for this field,aiming to offer guidance for future breakthroughs in the energy storage and conversion applications of metal fluorides.展开更多
Fluoride(F^(-))and arsenic,present as As(Ⅲ)and As(Ⅴ),are widespread toxins in groundwater across India,as well as in other countries or regions like Pakistan,China,Kenya,Africa,Thailand,and Latin America.Their prese...Fluoride(F^(-))and arsenic,present as As(Ⅲ)and As(Ⅴ),are widespread toxins in groundwater across India,as well as in other countries or regions like Pakistan,China,Kenya,Africa,Thailand,and Latin America.Their presence in water resources poses significant environmental and health risks,including fluorosis and arsenicosis.To address this issue,this study developed an integrated process combining biosorbents and ultrafiltration(UF)for the removal of F^(-),As,and turbidity from contaminated water.Laboratory-scale adsorption experiments were conducted using low-cost biosorbents with different biosorbent dosages,specifically Moringa oleifera seed powder(MSP)and sorghum bicolor husk(SBH),along with sand as a binding medium.F^(-)and As concentrations ranging from 2 to 10 mg/L and 3 to 12 mg/L,respectively,were investigated.Biosorbents and their different combinations were tested to determine their efficacy in removing dissolved F^(-)and As.The results showed that a blend of 10-g/L MSP with SBH achieved the highest F^(-)(97.20%)and As(78.63%)removal efficiencies.Subsequent treatment with a UF membrane effectively reduced turbidity and colloidal impurities in the treated water,achieving a maximum turbidity removal efficiency of 95.40%.Equilibrium kinetic and isotherm models were employed to analyze the experimental data,demonstrating good fit.Preliminary cost analysis indicated that the hybrid technology is economically viable and suitable for the separation of hazardous contaminants from aqueous solutions.This study underscores the potential of inexpensive biosorption technologies in providing clean and safe drinking water,particularly in industrial,rural,and urban areas.展开更多
In the published version of our article(Shaji et al.,2024),in the last paragraph of the article,Hong Kong should be corrected to Hong Kong(China)and the repetition of Spain and Ireland in the same sentence need to be ...In the published version of our article(Shaji et al.,2024),in the last paragraph of the article,Hong Kong should be corrected to Hong Kong(China)and the repetition of Spain and Ireland in the same sentence need to be deleted.The correct sentence is as below.展开更多
The primary objective of this study is to measure fluoride levels in groundwater samples using machine learning approaches alongside traditional and fuzzy logic models based health risk assessment in the hard rock Arj...The primary objective of this study is to measure fluoride levels in groundwater samples using machine learning approaches alongside traditional and fuzzy logic models based health risk assessment in the hard rock Arjunanadi River basin,South India.Fluoride levels in the study area vary between 0.1 and 3.10 mg/L,with 32 samples exceeding the World Health Organization(WHO)standard of 1.5 mg/L.Hydrogeochemical analyses(Durov and Gibbs)clearly show that the overall water chemistry is primarily influenced by simple dissolution,mixing,and rock-water interactions,indicating that geogenic sources are the predominant contributors to fluoride in the study area.Around 446.5 km^(2)is considered at risk.In predictive analysis,five Machine Learning(ML)models were used,with the AdaBoost model performing better than the other models,achieving 96%accuracy and 4%error rate.The Traditional Health Risk Assessment(THRA)results indicate that 65%of samples pose highly susceptible for dental fluorosis,while 12%of samples pose highly susceptible for skeletal fluorosis in young age groups.The Fuzzy Inference System(FIS)model effectively manages ambiguity and linguistic factors,which are crucial when addressing health risks linked to groundwater fluoride contamination.In this model,input variables include fluoride concentration,individual age,and ingestion rate,while output variables consist of dental caries risk,dental fluorosis,and skeletal fluorosis.The overall results indicate that increased ingestion rates and prolonged exposure to contaminated water make adults and the elderly people vulnerable to dental and skeletal fluorosis,along with very young and young age groups.This study is an essential resource for local authorities,healthcare officials,and communities,aiding in the mitigation of health risks associated with groundwater contamination and enhancing quality of life through improved water management and health risk assessment,aligning with Sustainable Development Goals(SDGs)3 and 6,thereby contributing to a cleaner and healthier society.展开更多
Groundwater is essential for maintaining public health,promoting economic development,and ensuring ecosystem stability in arid and semi-arid regions.The northwestern Ordos Basin(China)primarily relies on groundwater f...Groundwater is essential for maintaining public health,promoting economic development,and ensuring ecosystem stability in arid and semi-arid regions.The northwestern Ordos Basin(China)primarily relies on groundwater from multilayered aquifer systems;however,our knowledge of the hydrochemical characteristics and water quality of groundwater in this region is limited.Here,we employed a newly collected dataset of 94 groundwater samples from different aquifers to constrain the source,controlling processes of fluoride in groundwater,and its potential health risk in the area.Groundwater is characterized by Na-Cl and Na-SO_(4) types with a minor Na-HCO_(3) type,which is primarily controlled by ion exchange,silicate weathering,and the dissolution of carbonate and evaporite minerals.Of the groundwater samples,42%exceeded the fluoride limit of 1.5 mg/L established by the World Health Organization(WHO).This is mainly attributed to geogenic sources,including fluorine-bearing mineral dissolution,cation exchange,evaporation,and competitive adsorption.The water quality index suggests that most samples are unsuitable for drinking.Health risk assessment results based on the Monte Carlo simulation indicate that children face significantly higher non-carcinogenic health risks from fluoride exposure than adults(both males and females).These findings provide new insights into the complex hydrogeochemical evolution of fluoride in groundwater and the groundwater quality status in multi-aquifer systems,contributing to the sustainable development and management of groundwater resources in the Ordos Basin.展开更多
This research examines the hard-rock aquifer system within the Nagavathi River Basin(NRB)South India,by evaluating seasonal fluctuations in groundwater composition during the pre-monsoon(PRM)and post-monsoon(POM)perio...This research examines the hard-rock aquifer system within the Nagavathi River Basin(NRB)South India,by evaluating seasonal fluctuations in groundwater composition during the pre-monsoon(PRM)and post-monsoon(POM)periods.Seasonal variations significantly influence the groundwater quality,particularly fluoride(F−)concentrations,which can fluctuate due to changes in recharge,evaporation,and anthropogenic activities.This study assesses the dynamics of F−levels in PRM and POM seasons,and identifies elevated health risks using USEPA guidelines and Monte Carlo Simulations(MCS).Groundwater in the study area exhibits alkaline pH,with NaCl and Ca-Na-HCO_(3) facies increasing in the POM season due to intensified ion exchange and rock-water interactions,as indicated in Piper and Gibb’s diagrams.Correlation and dendrogram analyses indicate that F−contamination is from geogenic and anthropogenic sources.F−levels exceed the WHO limit(1.5 mg/L)in 51 PRM and 28 POM samples,affecting 371.74 km^(2) and 203.05 km^(2),respectively.Geochemical processes,including mineral weathering,cation exchange,evaporation,and dilution,are identified through CAI I&II.Health risk assessments reveal that HQ values>1 in 78%of children,73%of teens,and 68%of adults during PRM,decreasing to 45%,40%,and 38%,respectively,in POM.MCS show maximum HQ values of 5.67(PRM)and 4.73(POM)in children,with all age groups facing significant risks from fluoride ingestion.Managed Aquifer Recharge(MAR)is recommended in this study to minimize F−contamination,ensuring safe drinking water for the community.展开更多
Ti6Al4V alloy has been widely used in dental applications,such as orthodontic mini-implants.However,it has been reported that fluoride ions could obviously accelerate the corrosion of implant materials and affect thei...Ti6Al4V alloy has been widely used in dental applications,such as orthodontic mini-implants.However,it has been reported that fluoride ions could obviously accelerate the corrosion of implant materials and affect their performance.This work aimed to improve the F^(−)erosion resistance of Ti6Al4V alloy through the strategy of both Cu addition and grain refinement.As contrasted with Ti6Al4V alloy,both the coarse-and ultrafine-grained Ti6Al4V-5Cu alloys effectively mitigated the acceleration of the fluoride ions to the anode process,because Cu substituents blocked the continuous damage of F·_(O) doped in the passive film.Furthermore,grain refinement enhanced the protective ability of the passive film,more oxides and less adsorption amount of fluorides presented in the passive film of ultrafine-grained Ti6Al4V-5Cu alloy than those of coarse-grained Ti6Al4V-5Cu alloy.Under the combination of Cu alloying and grain refinement,the ultrafine-grained Ti6Al4V-5Cu alloy is greatly appropriate for the fabrication of orthodontic devices.展开更多
Sodium fluoride(NaF)is a daily necessity consumed as the major ingredient of fluorinated drinking water,milk,salts,mouthwashes,toothpaste,and dentistry medications.However,the use of NaF products has also been associa...Sodium fluoride(NaF)is a daily necessity consumed as the major ingredient of fluorinated drinking water,milk,salts,mouthwashes,toothpaste,and dentistry medications.However,the use of NaF products has also been associated with increased fluoride anion distribution in the body,leading to hypertension.AIM This study evaluated the antihypertensive effect of sweet orange peels-enriched white melon seed protein concentrate(WSP)biscuit meal in eight-week-old albino rats exposed to NaF for 14 days.METHODS Forty-two(42)male Wistar albino rats were assigned at random into 7 groups of 6 rats per group(control group and six experimental groups).The experimental groups received various treatments that lasted for two weeks.Twenty-four hours after the last administration,hemodynamic parameters were evaluated,rats were sacrificed,blood samples were collected,and the heart was harvested.Blood serum was assessed for cardiac troponin I(cTnI),creatine kinase-MB(CK-MB),and lactate dehydrogenase(LDH).At the same time,the heart homogenate was assayed for angiotensin-1 converting enzyme(ACE)activity,proinflammatory cytokines,nitric oxide concentrations,and antioxidant status.Cardiac tissues were stained with Hematoxylin and Eosin,Masson’s Trichrome,and cTnI.Also,the safety of the WSP biscuit diet was evaluated.RESULTS Results obtained showed that NaF administration elevated the collagen content of cardiac tissues,activities of ACE,and concentrations of cTnI,CK-MB,LDH,tumor necrosis factor-alpha,and interleukin 1 beta,while there was a reduction in the concentration of nitric oxide and antioxidants;however,their alterations were significantly prevented in WSP-biscuit-fed rats.The WSP biscuit meal is safe for consumption and possesses dose-dependent antihypertensive ability at 10%and 20%inclusion.CONCLUSION The WSP biscuit diet may be recommended in diet formulation for the management of individuals or communities that are predisposed to NaF contaminations.展开更多
To remove the fluoride in zinc sulfate electrolyte to an appropriate level,mitigate environmental fluoride pollution,and drive the development of the hydrometallurgy industry of zinc,a novel Fe_(3)O_(4)@SiO_(2)@Fe-MIL...To remove the fluoride in zinc sulfate electrolyte to an appropriate level,mitigate environmental fluoride pollution,and drive the development of the hydrometallurgy industry of zinc,a novel Fe_(3)O_(4)@SiO_(2)@Fe-MIL-101 magnetic composite material was successfully synthesized via the one-pot method.Preparation conditions were optimized and structural characterization of this material conducted using FTIR,SEM,EDS,XRD and Hysteresis analysis.The results show that this composite exhibits a more rapid fluoride adsorption dynamics and a higher fluoride adsorption capacity(18.34 mg/g)and its adsorption behavior fitted for the first order dynamic model and the Freundlich isotherm model.The adsorption of fluorine by this composite is mainly physical adsorption according to the mean adsorption energy(1.216 kJ/mol).The interfering ions co-existed in fluoride-containing solutions,like HCO_(3)^(-),NO^(-)and Cl^(-),have a significant effect on fluorine adsorption.This composite has also been proved with magnetism,higher adsorption selectivity and satisfactory reusability.When this composite is employed as an adsorbent for adsorption removing fluoride in zinc sulfate electrolyte,it exhibits higher pH-dependent behavior as well as high fluoride removal efficiency at pH 6.5.展开更多
Highly oriented poly(vinylidene fluoride)(PVDF)ultrathin films with differentβ-phase contents were prepared using the melt-draw method.The effect ofβ-phase content onα-βphase transition of highly oriented PVDF ult...Highly oriented poly(vinylidene fluoride)(PVDF)ultrathin films with differentβ-phase contents were prepared using the melt-draw method.The effect ofβ-phase content onα-βphase transition of highly oriented PVDF ultrathin films induced by stretching was investigated using transmission electron microscopy(TEM)and Fourier transform infrared(FTIR)spectroscopy.The results show that stretching can enhance the crystallinity and increase the average thickness of the lamellae.A fullα-βphase transition can be achieved for PVDF ultrathin films of 20.6%βphase stretched to aλ(stretching ratio)of 1.5,while fewαphases still exist for ultrathin films of 35.0%βphase,together with bent and tilted lamellae.Compared to thicker PVDF films undergoing stretching-inducedα-βphase transition,the higherα-βphase transition efficiency of the PVDF ultrathin films can be attributed to the parallel aligned lamellar structure.Moreover,a higherβ-phase content can suppressα-βphase transition because of the stress concentration effect ofβ-phase.Ultimately,these results provide valuable insights into the stretching-inducedα-βphase transition of PVDF ultrathin films.展开更多
Water fluoride pollution has caused non-negligible harm to the environment and humans,and thus it is crucial to find a suitable treatment technology.In this study,La-Fe@PTA adsorbent was synthesized for the defluorida...Water fluoride pollution has caused non-negligible harm to the environment and humans,and thus it is crucial to find a suitable treatment technology.In this study,La-Fe@PTA adsorbent was synthesized for the defluoridation of mine water.The results showed that the optimum conditions for defluoridation by La-Fe@PTA were p H close to 7.0,the initial F-concentration of 10 mg/L,the dosage of 0.5 g/L and the adsorption time of 240 min.Compared with SO_4^(2-),Cl^(-),NO_(3)^(-),Ca^(2+)and Mg^(2+),CO_(3)^(2-)and HCO_(3)^(-)presented severer inhibition on fluoride uptake by La-Fe@PTA.The adsorption process fits well with the pseudo-second-order kinetic model and Freundlich model,and the maximum adsorption capacity of Langmuir model was 95 mg/g.Fixed-bed adsorption results indicated that fluoride in practical fluorinated mine water could be effectively removed from 3.6 mg/L to less than 1.5 mg/L within130 bed volume(BV)by using 1.5 g La-Fe@PTA.Furthermore,the adsorbent still had good adsorption capacity after regeneration,which confirms the great application potential of La-Fe@PTA as a fluoride ion adsorbent.The mechanism analysis showed that La-Fe@PTA adsorption of fluorine ions is a physicochemical reaction driven by electrostatic attraction and ion exchange.展开更多
Fluoride and nitrate enriched groundwater are potential threats to the safety of the groundwater supply that may cause significant effects on human health and public safety,especially in aggregated population areas an...Fluoride and nitrate enriched groundwater are potential threats to the safety of the groundwater supply that may cause significant effects on human health and public safety,especially in aggregated population areas and economic hubs.This study focuses on the high F^(−)and NO_(3)^(−)concentration groundwater in Tongzhou District,Beijing,North China.A total of 36 groundwater samples were collected to analyze the hydrochemical characteristics,elucidate genetic mechanisms and evaluate the potential human health risks.The results of the analysis indicate:Firstly,most of the groundwater samples are characterized by Mg-HCO_(3) and Na-HCO_(3) with the pH ranging from 7.19 to 8.28 and TDS with a large variation across the range 471-2337 mg/L.The NO_(3)^(−)concentration in 38.89%groundwater samples and the F^(−)concentration in 66.67%groundwater samples exceed the permissible limited value.Secondly,F^(−)in groundwater originates predominantly from water-rock interactions and the fluorite dissolution,which is also regulated by cation exchange,competitive adsorption of HCO_(3)−and an alkaline environment.Thirdly,the effect of sewage disposal and agricultural activities have a significant effect on high NO3-concentration,while the high F^(−)concentration is less influenced by anthropogenic activity.The alkaline environment favors nitrification,thus being conducive to the production of NO_(3)^(−).Finally,the health risk assessment is evaluated for different population groups.The results indicate that high NO_(3)^(−)and F^(−)concentration in groundwater would have the largest threat to children’s health.The findings of this study could contribute to the provision of a scientific basis for groundwater supply policy formulation relating to public health in Tongzhou District.展开更多
Defluoridation of coal mining water is of great significance for sustainable development of coal industry in western China.A novel one-step mechanochemical method was developed to prepare polymeric aluminum modified p...Defluoridation of coal mining water is of great significance for sustainable development of coal industry in western China.A novel one-step mechanochemical method was developed to prepare polymeric aluminum modified powder activated carbon(PAC)for effective fluoride removal from coal mining water.Aluminum was stably loaded on the PAC through facile solid-phase reaction between polymeric aluminum(polyaluminum chloride(PACl)or polyaluminum ferric chloride(PAFC))and PAC(1:15 W/W).Fluoride adsorption on PACl and PAFC modified PAC(C-PACl and C-PAFC)all reached equilibrium within 5 min,at rate of 2.56 g mg^(-1)sec^(-1)and 1.31 g mg^(-1)sec^(-1)respectively.Larger increase of binding energy of Al on C-PACl(Al–F bond:76.64 eV and Al–FOH bond:77.70 eV)relative to that of Al on C-PAFC(Al–F bond:76.52 eV)explained higher fluoride uptake capacity of C-PACl.Less chloride was released from C-PACl than that from C-PAFC due to its higher proportion of covalent chlorine and lower proportion of ionic chlorine.The elements mapping and atomic composition proved the stability of Al loaded on the PAC as well as the enrichment of fluoride on both CPACl and C-PAFC.The Bader charge,formation energy and bond length obtained from DFT computational results explained the fluoride adsorption mechanism further.The carbon emission was 7.73 kg CO_(2)-eq/kg adsorbent prepared through mechanochemical process,which was as low as 1:82.3 to 1:8.07×10^(4)compared with the ones prepared by conventional hydrothermal methods.展开更多
During postmortem storage,fluoride in Antarctic krill can be enriched in the muscle.Trypsin,as the most important digestive enzyme in Antarctic krill with a high activity in low temperature,plays a potential role in t...During postmortem storage,fluoride in Antarctic krill can be enriched in the muscle.Trypsin,as the most important digestive enzyme in Antarctic krill with a high activity in low temperature,plays a potential role in this process.In this study,endogenous trypsin was purified and its properties were investigated.The involvement of trypsin in the generation of free fluoride from Antarctic krill cuticle was explored.Cuticle microstructure before and after hydrolysis was compared with scanning electron microscopy,and the ash samples of the hydrolyzed Antarctic krill cuticle were analyzed with X-ray diffraction,Fourier transform infrared spectroscopy,and electron dispersive spectroscopy,respectively.Mass spectrometry analysis and inhibition tests confirmed that the purified enzyme was endogenous trypsin.Results of the present study indicated that trypsin digestion caused the increases of the concentrations of both fluoride ions and free amino N simultaneously,while the protein coated on the cuticle surface was dissolved too.However,no compositional change was detected in the cuticle inorganic salts.These findings suggest that trypsin triggered free fluoride release from Antarctic krill cuticle.In addition,the kinetics of free fluoride release could be described by the equation C_(W)=(1-0.97^(-0.006t)-0.03e^(0.0558t))×337.53+10.50.The present study improved the understanding of the role of trypsin in free fluoride release from Antarctic krill cuticle,facilitating future studies aimed at reducing the fluoride content in krill protein during Antarctic krill processing.展开更多
Recycling graphite anode from spent lithium-ion batteries(SLIBs)is regarded as a crucial approach to promoting sustainable energy storage industry.However,the recycled graphite(RG)generally presents degraded structure...Recycling graphite anode from spent lithium-ion batteries(SLIBs)is regarded as a crucial approach to promoting sustainable energy storage industry.However,the recycled graphite(RG)generally presents degraded structure and performance.Herein,the residual fluoride self-activated effect is proposed for the upgraded utilization of RG.Simple and low-energy water immersion treatment not only widens the interlayer spacing,but also retains appropriate fluoride on the surface of RG.Theoretical analysis and experiments demonstrate that the residual fluoride can optimize Li~+migration and deposition kinetics,resulting in better Li~+intercalation/deintercalation in the interlayer and more stable Li metal plating/stripping on the surface of RG,As a result,the designed LFP||RG full cells achieve ultrahigh reversibility(~100%Coulombic efficiency),high capacity retention(67%after 200 cycles,0.85 N/P ratio),and commendable adaptability(stable cycling without short-circuiting,0.15 N/P ratio).The energy density is improved from 334 Wh kg^(-1)of 1.1 N/P ratio to 367 Wh kg^(-1)of 0.85 N/P ratio(total mass based on cathode and anode).The exploration of RG by residual fluoride self-activated effect achieves upgraded utilization beyond fresh commercial graphite and highlights a new strategy for efficient reuse of SLIBs.展开更多
Fluoride is an important pollutant in wastewater,and adsorption is an effective way to remove fluoride.Because nitrogen plays an important role in adsorbent materials,computational models were developed to understand ...Fluoride is an important pollutant in wastewater,and adsorption is an effective way to remove fluoride.Because nitrogen plays an important role in adsorbent materials,computational models were developed to understand the changes in work function resulting from nitrogen doping.La-N-C-800℃,was prepared by pyrolyzing La-MOF-NH_(2)to verify the influence on the performance of removing fluoride by electrosorption.Material and electrochemical performance tests were performed to characterize La-N-C-800℃.Adsorption kinetics,adsorption thermodynamics,initial concentrations,pH,and ions competition were investigated using La-N-C-800℃for fluoride removal.In addition,density functional theory was applied to evaluate the function of nitrogen.When nitrogen atoms were added,the density of states,partial density of states,populations,and different orbits of charge were calculated to discover deep changes.Nitrogen strengthened the carbon structure and La_(2)O_(3)structure to remove fluoride.In addition,nitrogen can also act as an adsorption site in the carbon structure.These results provide design ideas for improving the performance of adsorbent materials by doping elements.展开更多
The quality upgrading and deashing of inferior coal by chemical method still faces great challenges.The dangers of strong acid,strong alkali,waste water and exhaust gas as well as high cost limit its industrial produc...The quality upgrading and deashing of inferior coal by chemical method still faces great challenges.The dangers of strong acid,strong alkali,waste water and exhaust gas as well as high cost limit its industrial production.This paper systematically investigates the ash reduction and desilicification of two typical inferior coal utilizing ammonium fluoride roasting method.Under the optimal conditions,for fat coal and gas coal,the deashing rates are 69.02%and 54.13%,and the desilicification rates are 92.64%and 90.27%,respectively.The molar dosage of ammonium fluoride remains consistent for both coals;however,the gas coal,characterized by a lower ash and silica content(less than half that of the fat coal),achieves optimum deashing effect at a reduced time and temperature.The majority of silicon in coal transforms into gaseous ammonium fluorosilicate,subsequently preparing nanoscale amorphous silica with a purity of 99.90%through ammonia precipitation.Most of the fluorine in deashed coal are assigned in inorganic minerals,suggesting the possibility of further fluorine and ash removal via flotation.This research provides a green and facile route to deash inferior coal and produce nano-scale white carbon black simultaneously.展开更多
The growing concern about thermal conductivityand electromagnetic shielding inelectronic equipment has promoted the development of interfacial film materials.In this work,polyvinylidene fluoride(PVDF)/graphene composi...The growing concern about thermal conductivityand electromagnetic shielding inelectronic equipment has promoted the development of interfacial film materials.In this work,polyvinylidene fluoride(PVDF)/graphene composite films with different graphene contents were fabricated by high-energy ball milling,cold isostatic pressing,scraping and coating,successively.High-energy ball milling is beneficial to the dispersion of graphene powder,while cold isostatic pressing can greatly enhance thermal conductivity and mechanical strength by reducing the voids in the film and increasing the contact area of graphene sheets.The thermal conductivity,tensile strength and electromagnetic shielding properties of the films were carefully investigated and compared.It was demonstrated that the thermal conductivity increased from 0.19 W·m^(-1).K^(-1) for pure PVDF to 103.9 W·m^(-1).K^(-1)for the composite film with PVDF:graphene=1:3.Meanwhile the electromagnetic shielding efficiency can reach 36.55 dB.The prepared PVDF/graphene composite films exhibit outstanding overall performance and have the potential for practical applications.展开更多
Using a titration setup to accurately control the reaction conditions and in situ monitor the reaction,we showed that fluoride exhibited negligible effects on the ion association process of calcium and phosphate and t...Using a titration setup to accurately control the reaction conditions and in situ monitor the reaction,we showed that fluoride exhibited negligible effects on the ion association process of calcium and phosphate and the formation of ACP nanospheres in a buffer solution with constant ionic strength.However,the stability of ACP increased with increasing fluoride concentration,which was ascribed to the inhibitory effect of fluoride on the aggregation of ACP nanospheres and the nucleation of nanocrystals on the surface of ACP nanospheres.Furthermore,fluoride could inhibit the lateral growth of HAP nanosheets and promote the formation of rod-like crystals.These results further improve our understanding of the crystallization pathway of HAP crystals and the regulatory effects of fluoride.展开更多
Exploring wide voltage window materials is not only an available measure to enhance the energy density of hybrid supercapacitor(HSCs),but also avoids the dynamic mismatch caused by different energy storage mechanisms ...Exploring wide voltage window materials is not only an available measure to enhance the energy density of hybrid supercapacitor(HSCs),but also avoids the dynamic mismatch caused by different energy storage mechanisms of two electrodes in assembled symmetrical HSC.However,there are few reports about the wide potential window materials except Bi_(2)O_(3)and VO_(2).Therefore,the MnF_(2)synthesized by solvothermal reaction was served as the electrode for HSC.The MnF_(2)exhibited electrochemical activity in alkaline solution in three-electrode system,especially with a wide potential window from-0.8 to+0.5 V in 2 mol·L^(-1)NaOH.Furthermore,the assembled MnF_(2)//MnF_(2)symmetrical HSC had a potential window of 1.5 V,and it exhibited outstanding long-cycle capability.Meanwhile,when MnF_(2)was taken as the negative and positive respectively,the potential windows of asymmetric devices CoMoO_(4)//MnF_(2)and MnF_(2)//Activated Carbon(AC)could reach 1.3 and 1.45 V,respectively,showing excellent cycle stability.This work shows that MnF_(2)material has great research value in HSC,and provides a new research direction for developing high-performance devices.展开更多
基金National Natural Science Foundation of China,Grant/Award Number:51073067Scientific and Technological Development Program of Jilin Province,Grant/Award Number:20220201138GX.
文摘In recent years,renewable energy sources,which aim to replace rapidly depleting fossil fuels,face challenges due to limited energy storage and conversion technologies.To enhance energy storage and conversion efficiency,extensive research has been conducted in the academic community on numerous potential materials.Among these materials,metal fluorides have attracted significant attention due to their ionic metal-fluorine bonds and tunable electronic structures,attributed to the highest electronegativity of fluorine in their chemical composition.This makes them promising candidates for future electrochemical applications in various fields.However,metal fluorides encounter various challenges in different application directions.Therefore,we comprehensively review the applications of metal fluorides in the field of energy storage and conversion,aiming to deepen our understanding of their exhibited characteristics in different electrochemical processes.In this paper,we summarize the difficulties and improvement methods encountered in different types of battery applications and several typical electrode optimization strategies in the field of supercapacitors.In the field of water electrolysis,we focus on surface reconstruction and the critical role of fluorine,demonstrating the catalytic performance of metal fluorides from the perspectives of reconstruction mechanism and process analysis.Finally,we provide a summary and outlook for this field,aiming to offer guidance for future breakthroughs in the energy storage and conversion applications of metal fluorides.
文摘Fluoride(F^(-))and arsenic,present as As(Ⅲ)and As(Ⅴ),are widespread toxins in groundwater across India,as well as in other countries or regions like Pakistan,China,Kenya,Africa,Thailand,and Latin America.Their presence in water resources poses significant environmental and health risks,including fluorosis and arsenicosis.To address this issue,this study developed an integrated process combining biosorbents and ultrafiltration(UF)for the removal of F^(-),As,and turbidity from contaminated water.Laboratory-scale adsorption experiments were conducted using low-cost biosorbents with different biosorbent dosages,specifically Moringa oleifera seed powder(MSP)and sorghum bicolor husk(SBH),along with sand as a binding medium.F^(-)and As concentrations ranging from 2 to 10 mg/L and 3 to 12 mg/L,respectively,were investigated.Biosorbents and their different combinations were tested to determine their efficacy in removing dissolved F^(-)and As.The results showed that a blend of 10-g/L MSP with SBH achieved the highest F^(-)(97.20%)and As(78.63%)removal efficiencies.Subsequent treatment with a UF membrane effectively reduced turbidity and colloidal impurities in the treated water,achieving a maximum turbidity removal efficiency of 95.40%.Equilibrium kinetic and isotherm models were employed to analyze the experimental data,demonstrating good fit.Preliminary cost analysis indicated that the hybrid technology is economically viable and suitable for the separation of hazardous contaminants from aqueous solutions.This study underscores the potential of inexpensive biosorption technologies in providing clean and safe drinking water,particularly in industrial,rural,and urban areas.
文摘In the published version of our article(Shaji et al.,2024),in the last paragraph of the article,Hong Kong should be corrected to Hong Kong(China)and the repetition of Spain and Ireland in the same sentence need to be deleted.The correct sentence is as below.
基金the Anusandhan National Research Foundation(ANRF),New Delhi[Erstwhile,Science and Engineering Research Board(SERB)]Department of Science and Technology(DST)(Government of India)(File No.:CRG/2022/002618 Dated:22.08.2023)for providing the grant and support to carry out this work effectively.
文摘The primary objective of this study is to measure fluoride levels in groundwater samples using machine learning approaches alongside traditional and fuzzy logic models based health risk assessment in the hard rock Arjunanadi River basin,South India.Fluoride levels in the study area vary between 0.1 and 3.10 mg/L,with 32 samples exceeding the World Health Organization(WHO)standard of 1.5 mg/L.Hydrogeochemical analyses(Durov and Gibbs)clearly show that the overall water chemistry is primarily influenced by simple dissolution,mixing,and rock-water interactions,indicating that geogenic sources are the predominant contributors to fluoride in the study area.Around 446.5 km^(2)is considered at risk.In predictive analysis,five Machine Learning(ML)models were used,with the AdaBoost model performing better than the other models,achieving 96%accuracy and 4%error rate.The Traditional Health Risk Assessment(THRA)results indicate that 65%of samples pose highly susceptible for dental fluorosis,while 12%of samples pose highly susceptible for skeletal fluorosis in young age groups.The Fuzzy Inference System(FIS)model effectively manages ambiguity and linguistic factors,which are crucial when addressing health risks linked to groundwater fluoride contamination.In this model,input variables include fluoride concentration,individual age,and ingestion rate,while output variables consist of dental caries risk,dental fluorosis,and skeletal fluorosis.The overall results indicate that increased ingestion rates and prolonged exposure to contaminated water make adults and the elderly people vulnerable to dental and skeletal fluorosis,along with very young and young age groups.This study is an essential resource for local authorities,healthcare officials,and communities,aiding in the mitigation of health risks associated with groundwater contamination and enhancing quality of life through improved water management and health risk assessment,aligning with Sustainable Development Goals(SDGs)3 and 6,thereby contributing to a cleaner and healthier society.
基金supported by the Natural Science Foundation of Inner Mongolia Autonomous Region(2024QN04014)the Open Research Fund of Yinshanbeilu Grassland Eco-hydrology National Observation and Research Station,China Institute of Water Resources and Hydropower Research(Grant No.YSS202401)+2 种基金Scientific Research Support Program for Introducing Talents at the Inner Mongolia Autonomous Region of China(DC2400002177 and DC2400003177)Major Projects of Erdos Science and Technology(Project No.2022EEDSKJZDZX015)Applied technology research and development project in Jungar Banner of Inner Mongolia Autonomous Region of China(2023YY-13).
文摘Groundwater is essential for maintaining public health,promoting economic development,and ensuring ecosystem stability in arid and semi-arid regions.The northwestern Ordos Basin(China)primarily relies on groundwater from multilayered aquifer systems;however,our knowledge of the hydrochemical characteristics and water quality of groundwater in this region is limited.Here,we employed a newly collected dataset of 94 groundwater samples from different aquifers to constrain the source,controlling processes of fluoride in groundwater,and its potential health risk in the area.Groundwater is characterized by Na-Cl and Na-SO_(4) types with a minor Na-HCO_(3) type,which is primarily controlled by ion exchange,silicate weathering,and the dissolution of carbonate and evaporite minerals.Of the groundwater samples,42%exceeded the fluoride limit of 1.5 mg/L established by the World Health Organization(WHO).This is mainly attributed to geogenic sources,including fluorine-bearing mineral dissolution,cation exchange,evaporation,and competitive adsorption.The water quality index suggests that most samples are unsuitable for drinking.Health risk assessment results based on the Monte Carlo simulation indicate that children face significantly higher non-carcinogenic health risks from fluoride exposure than adults(both males and females).These findings provide new insights into the complex hydrogeochemical evolution of fluoride in groundwater and the groundwater quality status in multi-aquifer systems,contributing to the sustainable development and management of groundwater resources in the Ordos Basin.
文摘This research examines the hard-rock aquifer system within the Nagavathi River Basin(NRB)South India,by evaluating seasonal fluctuations in groundwater composition during the pre-monsoon(PRM)and post-monsoon(POM)periods.Seasonal variations significantly influence the groundwater quality,particularly fluoride(F−)concentrations,which can fluctuate due to changes in recharge,evaporation,and anthropogenic activities.This study assesses the dynamics of F−levels in PRM and POM seasons,and identifies elevated health risks using USEPA guidelines and Monte Carlo Simulations(MCS).Groundwater in the study area exhibits alkaline pH,with NaCl and Ca-Na-HCO_(3) facies increasing in the POM season due to intensified ion exchange and rock-water interactions,as indicated in Piper and Gibb’s diagrams.Correlation and dendrogram analyses indicate that F−contamination is from geogenic and anthropogenic sources.F−levels exceed the WHO limit(1.5 mg/L)in 51 PRM and 28 POM samples,affecting 371.74 km^(2) and 203.05 km^(2),respectively.Geochemical processes,including mineral weathering,cation exchange,evaporation,and dilution,are identified through CAI I&II.Health risk assessments reveal that HQ values>1 in 78%of children,73%of teens,and 68%of adults during PRM,decreasing to 45%,40%,and 38%,respectively,in POM.MCS show maximum HQ values of 5.67(PRM)and 4.73(POM)in children,with all age groups facing significant risks from fluoride ingestion.Managed Aquifer Recharge(MAR)is recommended in this study to minimize F−contamination,ensuring safe drinking water for the community.
基金supported by the Liaoning Provincial Science and Technology Program-Excellent Youth Fund Program(2023JH3/10200002)National Key Research and Development Program of China(2022YFC2406000)+1 种基金National Natural Science Foundation of China(52301308)IMR Innovation fund(2023-PY15).
文摘Ti6Al4V alloy has been widely used in dental applications,such as orthodontic mini-implants.However,it has been reported that fluoride ions could obviously accelerate the corrosion of implant materials and affect their performance.This work aimed to improve the F^(−)erosion resistance of Ti6Al4V alloy through the strategy of both Cu addition and grain refinement.As contrasted with Ti6Al4V alloy,both the coarse-and ultrafine-grained Ti6Al4V-5Cu alloys effectively mitigated the acceleration of the fluoride ions to the anode process,because Cu substituents blocked the continuous damage of F·_(O) doped in the passive film.Furthermore,grain refinement enhanced the protective ability of the passive film,more oxides and less adsorption amount of fluorides presented in the passive film of ultrafine-grained Ti6Al4V-5Cu alloy than those of coarse-grained Ti6Al4V-5Cu alloy.Under the combination of Cu alloying and grain refinement,the ultrafine-grained Ti6Al4V-5Cu alloy is greatly appropriate for the fabrication of orthodontic devices.
文摘Sodium fluoride(NaF)is a daily necessity consumed as the major ingredient of fluorinated drinking water,milk,salts,mouthwashes,toothpaste,and dentistry medications.However,the use of NaF products has also been associated with increased fluoride anion distribution in the body,leading to hypertension.AIM This study evaluated the antihypertensive effect of sweet orange peels-enriched white melon seed protein concentrate(WSP)biscuit meal in eight-week-old albino rats exposed to NaF for 14 days.METHODS Forty-two(42)male Wistar albino rats were assigned at random into 7 groups of 6 rats per group(control group and six experimental groups).The experimental groups received various treatments that lasted for two weeks.Twenty-four hours after the last administration,hemodynamic parameters were evaluated,rats were sacrificed,blood samples were collected,and the heart was harvested.Blood serum was assessed for cardiac troponin I(cTnI),creatine kinase-MB(CK-MB),and lactate dehydrogenase(LDH).At the same time,the heart homogenate was assayed for angiotensin-1 converting enzyme(ACE)activity,proinflammatory cytokines,nitric oxide concentrations,and antioxidant status.Cardiac tissues were stained with Hematoxylin and Eosin,Masson’s Trichrome,and cTnI.Also,the safety of the WSP biscuit diet was evaluated.RESULTS Results obtained showed that NaF administration elevated the collagen content of cardiac tissues,activities of ACE,and concentrations of cTnI,CK-MB,LDH,tumor necrosis factor-alpha,and interleukin 1 beta,while there was a reduction in the concentration of nitric oxide and antioxidants;however,their alterations were significantly prevented in WSP-biscuit-fed rats.The WSP biscuit meal is safe for consumption and possesses dose-dependent antihypertensive ability at 10%and 20%inclusion.CONCLUSION The WSP biscuit diet may be recommended in diet formulation for the management of individuals or communities that are predisposed to NaF contaminations.
基金National Natural Science Foundation of China(21865011)2024 Innovation and Entrepreneurship Project of College Student in Jishou University(JDCX20241122)。
文摘To remove the fluoride in zinc sulfate electrolyte to an appropriate level,mitigate environmental fluoride pollution,and drive the development of the hydrometallurgy industry of zinc,a novel Fe_(3)O_(4)@SiO_(2)@Fe-MIL-101 magnetic composite material was successfully synthesized via the one-pot method.Preparation conditions were optimized and structural characterization of this material conducted using FTIR,SEM,EDS,XRD and Hysteresis analysis.The results show that this composite exhibits a more rapid fluoride adsorption dynamics and a higher fluoride adsorption capacity(18.34 mg/g)and its adsorption behavior fitted for the first order dynamic model and the Freundlich isotherm model.The adsorption of fluorine by this composite is mainly physical adsorption according to the mean adsorption energy(1.216 kJ/mol).The interfering ions co-existed in fluoride-containing solutions,like HCO_(3)^(-),NO^(-)and Cl^(-),have a significant effect on fluorine adsorption.This composite has also been proved with magnetism,higher adsorption selectivity and satisfactory reusability.When this composite is employed as an adsorbent for adsorption removing fluoride in zinc sulfate electrolyte,it exhibits higher pH-dependent behavior as well as high fluoride removal efficiency at pH 6.5.
基金financially supported from the National Natural Science Foundation of China(Nos.52203026 and 52027804)。
文摘Highly oriented poly(vinylidene fluoride)(PVDF)ultrathin films with differentβ-phase contents were prepared using the melt-draw method.The effect ofβ-phase content onα-βphase transition of highly oriented PVDF ultrathin films induced by stretching was investigated using transmission electron microscopy(TEM)and Fourier transform infrared(FTIR)spectroscopy.The results show that stretching can enhance the crystallinity and increase the average thickness of the lamellae.A fullα-βphase transition can be achieved for PVDF ultrathin films of 20.6%βphase stretched to aλ(stretching ratio)of 1.5,while fewαphases still exist for ultrathin films of 35.0%βphase,together with bent and tilted lamellae.Compared to thicker PVDF films undergoing stretching-inducedα-βphase transition,the higherα-βphase transition efficiency of the PVDF ultrathin films can be attributed to the parallel aligned lamellar structure.Moreover,a higherβ-phase content can suppressα-βphase transition because of the stress concentration effect ofβ-phase.Ultimately,these results provide valuable insights into the stretching-inducedα-βphase transition of PVDF ultrathin films.
基金supported by the National Natural Science Foundation of China(No.51978658)。
文摘Water fluoride pollution has caused non-negligible harm to the environment and humans,and thus it is crucial to find a suitable treatment technology.In this study,La-Fe@PTA adsorbent was synthesized for the defluoridation of mine water.The results showed that the optimum conditions for defluoridation by La-Fe@PTA were p H close to 7.0,the initial F-concentration of 10 mg/L,the dosage of 0.5 g/L and the adsorption time of 240 min.Compared with SO_4^(2-),Cl^(-),NO_(3)^(-),Ca^(2+)and Mg^(2+),CO_(3)^(2-)and HCO_(3)^(-)presented severer inhibition on fluoride uptake by La-Fe@PTA.The adsorption process fits well with the pseudo-second-order kinetic model and Freundlich model,and the maximum adsorption capacity of Langmuir model was 95 mg/g.Fixed-bed adsorption results indicated that fluoride in practical fluorinated mine water could be effectively removed from 3.6 mg/L to less than 1.5 mg/L within130 bed volume(BV)by using 1.5 g La-Fe@PTA.Furthermore,the adsorbent still had good adsorption capacity after regeneration,which confirms the great application potential of La-Fe@PTA as a fluoride ion adsorbent.The mechanism analysis showed that La-Fe@PTA adsorption of fluorine ions is a physicochemical reaction driven by electrostatic attraction and ion exchange.
基金supported by the project of China Geological Survey(Grant No.DD20221677-2)the fundamental research funds of Chinese Academy of Geological Sciences Basal Research Fund(Grant No.JKYQN202307).
文摘Fluoride and nitrate enriched groundwater are potential threats to the safety of the groundwater supply that may cause significant effects on human health and public safety,especially in aggregated population areas and economic hubs.This study focuses on the high F^(−)and NO_(3)^(−)concentration groundwater in Tongzhou District,Beijing,North China.A total of 36 groundwater samples were collected to analyze the hydrochemical characteristics,elucidate genetic mechanisms and evaluate the potential human health risks.The results of the analysis indicate:Firstly,most of the groundwater samples are characterized by Mg-HCO_(3) and Na-HCO_(3) with the pH ranging from 7.19 to 8.28 and TDS with a large variation across the range 471-2337 mg/L.The NO_(3)^(−)concentration in 38.89%groundwater samples and the F^(−)concentration in 66.67%groundwater samples exceed the permissible limited value.Secondly,F^(−)in groundwater originates predominantly from water-rock interactions and the fluorite dissolution,which is also regulated by cation exchange,competitive adsorption of HCO_(3)−and an alkaline environment.Thirdly,the effect of sewage disposal and agricultural activities have a significant effect on high NO3-concentration,while the high F^(−)concentration is less influenced by anthropogenic activity.The alkaline environment favors nitrification,thus being conducive to the production of NO_(3)^(−).Finally,the health risk assessment is evaluated for different population groups.The results indicate that high NO_(3)^(−)and F^(−)concentration in groundwater would have the largest threat to children’s health.The findings of this study could contribute to the provision of a scientific basis for groundwater supply policy formulation relating to public health in Tongzhou District.
基金supported by the National Natural Science Foundation of China(No.52100070)the Science and Technology Innovation Project of China Energy Investment Corporation(No.SZY93002219N).
文摘Defluoridation of coal mining water is of great significance for sustainable development of coal industry in western China.A novel one-step mechanochemical method was developed to prepare polymeric aluminum modified powder activated carbon(PAC)for effective fluoride removal from coal mining water.Aluminum was stably loaded on the PAC through facile solid-phase reaction between polymeric aluminum(polyaluminum chloride(PACl)or polyaluminum ferric chloride(PAFC))and PAC(1:15 W/W).Fluoride adsorption on PACl and PAFC modified PAC(C-PACl and C-PAFC)all reached equilibrium within 5 min,at rate of 2.56 g mg^(-1)sec^(-1)and 1.31 g mg^(-1)sec^(-1)respectively.Larger increase of binding energy of Al on C-PACl(Al–F bond:76.64 eV and Al–FOH bond:77.70 eV)relative to that of Al on C-PAFC(Al–F bond:76.52 eV)explained higher fluoride uptake capacity of C-PACl.Less chloride was released from C-PACl than that from C-PAFC due to its higher proportion of covalent chlorine and lower proportion of ionic chlorine.The elements mapping and atomic composition proved the stability of Al loaded on the PAC as well as the enrichment of fluoride on both CPACl and C-PAFC.The Bader charge,formation energy and bond length obtained from DFT computational results explained the fluoride adsorption mechanism further.The carbon emission was 7.73 kg CO_(2)-eq/kg adsorbent prepared through mechanochemical process,which was as low as 1:82.3 to 1:8.07×10^(4)compared with the ones prepared by conventional hydrothermal methods.
基金supported by the Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety(No.GDPKLAPPS2005)the School Level Talent Project of Lingnan Normal University(No.ZL2021009)+2 种基金the Science and Technology Planning Project of Zhanjiang(No.2020A01040)the Study on the Preparation of Active Polypeptide from the Processing Waste of White Shrimp and its Fatigue Resistance(No.2021E05022)the Scientific Research Capacity Improvement Project of the Key Construction Discipline of Guangdong Province(No.2022ZD JS079).
文摘During postmortem storage,fluoride in Antarctic krill can be enriched in the muscle.Trypsin,as the most important digestive enzyme in Antarctic krill with a high activity in low temperature,plays a potential role in this process.In this study,endogenous trypsin was purified and its properties were investigated.The involvement of trypsin in the generation of free fluoride from Antarctic krill cuticle was explored.Cuticle microstructure before and after hydrolysis was compared with scanning electron microscopy,and the ash samples of the hydrolyzed Antarctic krill cuticle were analyzed with X-ray diffraction,Fourier transform infrared spectroscopy,and electron dispersive spectroscopy,respectively.Mass spectrometry analysis and inhibition tests confirmed that the purified enzyme was endogenous trypsin.Results of the present study indicated that trypsin digestion caused the increases of the concentrations of both fluoride ions and free amino N simultaneously,while the protein coated on the cuticle surface was dissolved too.However,no compositional change was detected in the cuticle inorganic salts.These findings suggest that trypsin triggered free fluoride release from Antarctic krill cuticle.In addition,the kinetics of free fluoride release could be described by the equation C_(W)=(1-0.97^(-0.006t)-0.03e^(0.0558t))×337.53+10.50.The present study improved the understanding of the role of trypsin in free fluoride release from Antarctic krill cuticle,facilitating future studies aimed at reducing the fluoride content in krill protein during Antarctic krill processing.
基金the National Natural Science Foundation of China(21975212)the Industry Leading Key Projects of Fujian Province(2022H0057)the High-level talent start-up Foundation of Xiamen Institute of Technology for financial support。
文摘Recycling graphite anode from spent lithium-ion batteries(SLIBs)is regarded as a crucial approach to promoting sustainable energy storage industry.However,the recycled graphite(RG)generally presents degraded structure and performance.Herein,the residual fluoride self-activated effect is proposed for the upgraded utilization of RG.Simple and low-energy water immersion treatment not only widens the interlayer spacing,but also retains appropriate fluoride on the surface of RG.Theoretical analysis and experiments demonstrate that the residual fluoride can optimize Li~+migration and deposition kinetics,resulting in better Li~+intercalation/deintercalation in the interlayer and more stable Li metal plating/stripping on the surface of RG,As a result,the designed LFP||RG full cells achieve ultrahigh reversibility(~100%Coulombic efficiency),high capacity retention(67%after 200 cycles,0.85 N/P ratio),and commendable adaptability(stable cycling without short-circuiting,0.15 N/P ratio).The energy density is improved from 334 Wh kg^(-1)of 1.1 N/P ratio to 367 Wh kg^(-1)of 0.85 N/P ratio(total mass based on cathode and anode).The exploration of RG by residual fluoride self-activated effect achieves upgraded utilization beyond fresh commercial graphite and highlights a new strategy for efficient reuse of SLIBs.
基金supported by the Jointly funded project of Guangzhou City School (College)of Guangzhou Basic Research Program (No.202201020205)the Talent Cultivation Program of Guangzhou University (Nos.RP2021014 and YJ2021005)+6 种基金the Guangdong Basic and Applied Basic Research Foundation (No.2021A1515110899)the Youth Innovative Talents Project of Guangdong Province (No.2021KQNCX062)the Basic and Applied Basic Research in Guangzhou (Nos.202201010001 and 201707010256)the Guangzhou University-Hong Kong University of Science and Technology Joint Research Cooperation Fund (No.YH202102)the National Natural Science Foundation of China (No.51778156)the Pearl River S&T Nova Program of Guangzhou (No.201806010191)the Guangdong Natural Science Foundation (No.2022A1515010441)。
文摘Fluoride is an important pollutant in wastewater,and adsorption is an effective way to remove fluoride.Because nitrogen plays an important role in adsorbent materials,computational models were developed to understand the changes in work function resulting from nitrogen doping.La-N-C-800℃,was prepared by pyrolyzing La-MOF-NH_(2)to verify the influence on the performance of removing fluoride by electrosorption.Material and electrochemical performance tests were performed to characterize La-N-C-800℃.Adsorption kinetics,adsorption thermodynamics,initial concentrations,pH,and ions competition were investigated using La-N-C-800℃for fluoride removal.In addition,density functional theory was applied to evaluate the function of nitrogen.When nitrogen atoms were added,the density of states,partial density of states,populations,and different orbits of charge were calculated to discover deep changes.Nitrogen strengthened the carbon structure and La_(2)O_(3)structure to remove fluoride.In addition,nitrogen can also act as an adsorption site in the carbon structure.These results provide design ideas for improving the performance of adsorbent materials by doping elements.
文摘The quality upgrading and deashing of inferior coal by chemical method still faces great challenges.The dangers of strong acid,strong alkali,waste water and exhaust gas as well as high cost limit its industrial production.This paper systematically investigates the ash reduction and desilicification of two typical inferior coal utilizing ammonium fluoride roasting method.Under the optimal conditions,for fat coal and gas coal,the deashing rates are 69.02%and 54.13%,and the desilicification rates are 92.64%and 90.27%,respectively.The molar dosage of ammonium fluoride remains consistent for both coals;however,the gas coal,characterized by a lower ash and silica content(less than half that of the fat coal),achieves optimum deashing effect at a reduced time and temperature.The majority of silicon in coal transforms into gaseous ammonium fluorosilicate,subsequently preparing nanoscale amorphous silica with a purity of 99.90%through ammonia precipitation.Most of the fluorine in deashed coal are assigned in inorganic minerals,suggesting the possibility of further fluorine and ash removal via flotation.This research provides a green and facile route to deash inferior coal and produce nano-scale white carbon black simultaneously.
基金This work was supported by the National Natural ScienceFoundationofChina(No.U22B2066,No.12064044)the Major Science and Technology Projects of Anhui Province(No.202103a05020016)+1 种基金the open competition project to select the best candidates to undertake major science and key research projectsofTonglingcity,AnhuiProvince(No.202101JB002)A proportion of this work was supported by the High Magnetic Field Laboratory of Anhui Province and Academician workstation of Hangzhou Xingyu Carbon Environmental Tech Co.,Ltd.,and the Hefei Institutes of Physical Science Director's Fund(No.YZJJ-GGZX-2022-01).
文摘The growing concern about thermal conductivityand electromagnetic shielding inelectronic equipment has promoted the development of interfacial film materials.In this work,polyvinylidene fluoride(PVDF)/graphene composite films with different graphene contents were fabricated by high-energy ball milling,cold isostatic pressing,scraping and coating,successively.High-energy ball milling is beneficial to the dispersion of graphene powder,while cold isostatic pressing can greatly enhance thermal conductivity and mechanical strength by reducing the voids in the film and increasing the contact area of graphene sheets.The thermal conductivity,tensile strength and electromagnetic shielding properties of the films were carefully investigated and compared.It was demonstrated that the thermal conductivity increased from 0.19 W·m^(-1).K^(-1) for pure PVDF to 103.9 W·m^(-1).K^(-1)for the composite film with PVDF:graphene=1:3.Meanwhile the electromagnetic shielding efficiency can reach 36.55 dB.The prepared PVDF/graphene composite films exhibit outstanding overall performance and have the potential for practical applications.
基金Funded by the National Natural Science Foundation of China(No.52172287)the National Key Research and Development Program of China(No.2021YFA0715700)。
文摘Using a titration setup to accurately control the reaction conditions and in situ monitor the reaction,we showed that fluoride exhibited negligible effects on the ion association process of calcium and phosphate and the formation of ACP nanospheres in a buffer solution with constant ionic strength.However,the stability of ACP increased with increasing fluoride concentration,which was ascribed to the inhibitory effect of fluoride on the aggregation of ACP nanospheres and the nucleation of nanocrystals on the surface of ACP nanospheres.Furthermore,fluoride could inhibit the lateral growth of HAP nanosheets and promote the formation of rod-like crystals.These results further improve our understanding of the crystallization pathway of HAP crystals and the regulatory effects of fluoride.
基金financially supported by the National Natural Science Foundation of China(No.52261040 and 51971104)。
文摘Exploring wide voltage window materials is not only an available measure to enhance the energy density of hybrid supercapacitor(HSCs),but also avoids the dynamic mismatch caused by different energy storage mechanisms of two electrodes in assembled symmetrical HSC.However,there are few reports about the wide potential window materials except Bi_(2)O_(3)and VO_(2).Therefore,the MnF_(2)synthesized by solvothermal reaction was served as the electrode for HSC.The MnF_(2)exhibited electrochemical activity in alkaline solution in three-electrode system,especially with a wide potential window from-0.8 to+0.5 V in 2 mol·L^(-1)NaOH.Furthermore,the assembled MnF_(2)//MnF_(2)symmetrical HSC had a potential window of 1.5 V,and it exhibited outstanding long-cycle capability.Meanwhile,when MnF_(2)was taken as the negative and positive respectively,the potential windows of asymmetric devices CoMoO_(4)//MnF_(2)and MnF_(2)//Activated Carbon(AC)could reach 1.3 and 1.45 V,respectively,showing excellent cycle stability.This work shows that MnF_(2)material has great research value in HSC,and provides a new research direction for developing high-performance devices.
