Water splitting,as an advanced energy conversion technology,consists of two half reactions,including oxygen evolution reaction(OER)and hydrogen evolution reaction(HER).However,the ideal electrocatalysts are noble meta...Water splitting,as an advanced energy conversion technology,consists of two half reactions,including oxygen evolution reaction(OER)and hydrogen evolution reaction(HER).However,the ideal electrocatalysts are noble metal based catalysts.Their high cost and scarcity in earth seriously restrict the large deployments.Ni Fe-based materials have attracted great attention in recent years due to their excellent catalytic properties for OER and HER.Nevertheless,their conductivity and electrochemical stability at high current density are unsatisfactory,resulting in ineffective water splitting due to high impedance and low stability.Recently,a series of catalysts coating Ni Fe-based materials on 3 D nickel foam were found to be extremely stable under the circumstance of high current density.In this review,we summarized the recent advances of NiFe-based materials on nickel foam for OER and HER,respectively,and further provided the perspectives for their future development.展开更多
Metal-free carbon-based materials are considered as promising oxygen reduction reaction(ORR)electrocatalysts for clean energy conversion,and their highly dense and exposed carbon active sites are crucial for efficient...Metal-free carbon-based materials are considered as promising oxygen reduction reaction(ORR)electrocatalysts for clean energy conversion,and their highly dense and exposed carbon active sites are crucial for efficient ORR.In this work,two unique quasi-three-dimensional cyclotriphosphazene-based covalent organic frameworks(Q3CTP-COFs)and their nanosheets were successfully synthesized and applied as ORR electrocatalysts.The abundant electrophilic structure in Q3CTP-COFs induces a high density of carbon active sites,and the unique bilayer stacking of[6+3]imine-linked backbone facilitates the exposure of active carbon sites and accelerates mass diffusion during ORR.In particular,bulk Q3CTP-COFs can be easily exfoliated into thin COF nanosheets(NSs)due to the weak interlayerπ-πinteractions.Q3CTP-COF NSs exhibit highly efficient ORR catalytic activity(half-wave potential of 0.72 V vs.RHE in alkaline electrolyte),which is one of the best COF-based ORR electrocatalysts reported so far.Furthermore,Q3CTP-COF NSs can serve as a promising cathode for Zn-air batteries(delivered power density of 156 mW cm-2 at 300 mA cm^(-2)).This judicious design and accurate synthesis of such COFs with highly dense and exposed active sites and their nanosheets will promote the development of metal-free carbon-based electrocatalysts.展开更多
Rapid advances in flexible and wearable smart textiles demand low-cost,high-energy/power-density fiber-shaped supercapacitors(FSCs).The performance of FSCs is determined by the fabrication and assembly of fiber-shaped...Rapid advances in flexible and wearable smart textiles demand low-cost,high-energy/power-density fiber-shaped supercapacitors(FSCs).The performance of FSCs is determined by the fabrication and assembly of fiber-shaped electrodes(FSEs),where an active charge-storage material is always clad around flexible charge transmission current collectors.Inspired by the tissue structure of natural bamboo,wherein parenchyma cells(PCs)that store nutrients are clad around bamboo fibers(BFs),we propose a strategy for converting bamboo cells into FSEs using conductive BFs and activated PCs as current collectors and active materials,respectively.The assembled electrode has a high specific capacitance of 1454 mF cm^(−2) at 0.64 mA cm^(−2).A solid-state FSC with a pair of bamboo-structured electrodes exhibited a substantially high energy density.Its mechanical flexibility enabled the knitting of wearable wristbands to drive ultra-small voltmeter indicators.This lightweight,low cost,and high-energy-density bamboostructured FSC could enable numerous smart textile applications.展开更多
Oxygen defects play a critical role in the electrocatalytic oxygen evolution reaction(OER).Therefore,in-depth understanding the structure-activity-mechanism relationship of these defects is the key to design efficient...Oxygen defects play a critical role in the electrocatalytic oxygen evolution reaction(OER).Therefore,in-depth understanding the structure-activity-mechanism relationship of these defects is the key to design efficient OER electrocatalysts.This relationship needs to be understood dynamically due to the potential for irreversible phase transitions during OER.Consequently,significant efforts have been devoted to study the dynamic evolution of oxygen defects to shed light on the OER mechanism.This review critically examines and analyzes the dynamic processes occurring at oxygen defect sites during OER,including defect formation and defect evolution mechanisms,along with the advanced characterization techniques needed to understand these processes.This review aims to provide a comprehensive understanding of high-efficiency electrocatalysts,with a particular emphasis on the importance of in situ monitoring the dynamic evolution of oxygen defects,providing a new perspective towards efficient OER electrocatalyst design.展开更多
Rationally constructed new catalyst can promote carbon dioxide reduction reaction(CO_(2)RR)to valuable carbo-naceous fuels such as formate and CO,providing a promising strategy for low CO_(2)emissions.Herein,the syn-t...Rationally constructed new catalyst can promote carbon dioxide reduction reaction(CO_(2)RR)to valuable carbo-naceous fuels such as formate and CO,providing a promising strategy for low CO_(2)emissions.Herein,the syn-thesized Ni_(3)S_(2)@C as a highly efficient electro-catalyst exhibits remarkable selectivity for formate with 73.9%faradaic efficiency(FE)at-0.7 V vs.RHE.At high applied potential,it shows a high syngas evolution with CO/H_(2)ratios(0.54-3.15)that are suitable for typical downstream thermochemical reactions.The experimental and theoretical analyses demonstrate that the electron-rich Ni^(2+)in Ni_(3)S_(2)enhances the adsorption behavior of*OCHO intermediate,reduces the energy barrier of the formation of intermediates,and improves the selectivity of the formate product.Attenuated total reflection surface-enhanced infrared absorption spectra conducted in situ show that*OCHO intermediate is more likely to be generated and adsorbed on Ni_(3)S_(2),enhancing the selectivity and activity of the formate product.展开更多
Iron sulfide(FeS)nanoparticles(termed FSNs)have attracted much attention for the removal of pollutants due to their high efficiency and low cost,and because they are environmentally friendly.However,issues of agglomer...Iron sulfide(FeS)nanoparticles(termed FSNs)have attracted much attention for the removal of pollutants due to their high efficiency and low cost,and because they are environmentally friendly.However,issues of agglomeration,transformation,and the loss of active components limit their application.Therefore,this study investigates in situ synthesized FeS/carbon fibers with an Fecarrageenan biomass as a precursor and nontoxic sulfur source to ascertain the removal efficiency of the fibers.The enrichment of sulfate groups as well as the double-helix structure in i-carrageenan-Fe could effectively avoid the aggregation and loss of FSNs in practical applications.The obtained FeS/carbon fibers were used to control a Cr(Ⅵ)polluted solution,and exhibited a relatively high removal capacity(81.62 mg/g).T he main mechanisms included the reduction of FeS,electrostatic adsorption of carbon fibers,and Cr(Ⅲ)-Fe(Ⅲ)complexation reaction.The pseudo-second-order kinetic model and Langmuir adsorption model both provided a good fit of the reaction process;hence,the removal process was mainly controlled by chemical adsorption,specifically monolayer adsorption on a uniform surface.Furthermore,co-existing anions,column,and regeneration experiments indicated that the FeS/carbon fibers are a promising remediation material for practical application.展开更多
Developing low-cost,efficient oxygen reduction reaction(ORR)catalysts to replace Pt-based materials is urgently required for the application of Zn-air batteries(ZABs)and microbial fuel cells(MFCs).In this work,meso-mi...Developing low-cost,efficient oxygen reduction reaction(ORR)catalysts to replace Pt-based materials is urgently required for the application of Zn-air batteries(ZABs)and microbial fuel cells(MFCs).In this work,meso-microporous carbon fibers with tunable defect density were synthesized by carrageenan fibers.A highly defective carbon fiber(HDCFs)was produced which exhibited an outstanding ORR catalytic activity,reaching to the half-wave potential of 0.841 and 0.44 V in alkaline and neutral electrolytes,respectively.These HDCFs can also act as highly efficient air cathodes for ZABs(delivered potential of 0.69 V and power density of 220 mW cm^(–2) at 300 mA cm^(–2))and MFCs(high power density of 69.7 mW cm^(–2)).Simulation by the density functional theory indicated that a high density of defections in a carbon based framework can remarkably modulate the electrical properties.For instance the charge entrapments in the carbon active sites may reduce the energy barrier of ORR.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.51473081 and 51672143)Taishan Scholars Program,Outstanding Youth of Natural Science in Shandong Province(JQ201713)+1 种基金Natural Science Foundation of Shandong Province(ZR2017MEM018)ARC Discovery Project(No.170103317)
文摘Water splitting,as an advanced energy conversion technology,consists of two half reactions,including oxygen evolution reaction(OER)and hydrogen evolution reaction(HER).However,the ideal electrocatalysts are noble metal based catalysts.Their high cost and scarcity in earth seriously restrict the large deployments.Ni Fe-based materials have attracted great attention in recent years due to their excellent catalytic properties for OER and HER.Nevertheless,their conductivity and electrochemical stability at high current density are unsatisfactory,resulting in ineffective water splitting due to high impedance and low stability.Recently,a series of catalysts coating Ni Fe-based materials on 3 D nickel foam were found to be extremely stable under the circumstance of high current density.In this review,we summarized the recent advances of NiFe-based materials on nickel foam for OER and HER,respectively,and further provided the perspectives for their future development.
基金supported by National Key R&D Prog ram of China (2022YFB3704900 and 2021YFF0500500)National Natural Science Foundation of China (22025504, 21621001, and 22105082)+4 种基金the SINOPEC Research Institute of Petroleum Processing"111"project (BP0719036 and B17020)China Postdoctoral Science Foundation (2020TQ0118 and 2020M681034)the program for JLU Science and Technology Innovative Research Teamthe Taishan Scholars Program (No. tsqn202211124)
文摘Metal-free carbon-based materials are considered as promising oxygen reduction reaction(ORR)electrocatalysts for clean energy conversion,and their highly dense and exposed carbon active sites are crucial for efficient ORR.In this work,two unique quasi-three-dimensional cyclotriphosphazene-based covalent organic frameworks(Q3CTP-COFs)and their nanosheets were successfully synthesized and applied as ORR electrocatalysts.The abundant electrophilic structure in Q3CTP-COFs induces a high density of carbon active sites,and the unique bilayer stacking of[6+3]imine-linked backbone facilitates the exposure of active carbon sites and accelerates mass diffusion during ORR.In particular,bulk Q3CTP-COFs can be easily exfoliated into thin COF nanosheets(NSs)due to the weak interlayerπ-πinteractions.Q3CTP-COF NSs exhibit highly efficient ORR catalytic activity(half-wave potential of 0.72 V vs.RHE in alkaline electrolyte),which is one of the best COF-based ORR electrocatalysts reported so far.Furthermore,Q3CTP-COF NSs can serve as a promising cathode for Zn-air batteries(delivered power density of 156 mW cm-2 at 300 mA cm^(-2)).This judicious design and accurate synthesis of such COFs with highly dense and exposed active sites and their nanosheets will promote the development of metal-free carbon-based electrocatalysts.
基金supported by the National Natural Science Foundation of China (No.31971738,32001380,32122058).
文摘Rapid advances in flexible and wearable smart textiles demand low-cost,high-energy/power-density fiber-shaped supercapacitors(FSCs).The performance of FSCs is determined by the fabrication and assembly of fiber-shaped electrodes(FSEs),where an active charge-storage material is always clad around flexible charge transmission current collectors.Inspired by the tissue structure of natural bamboo,wherein parenchyma cells(PCs)that store nutrients are clad around bamboo fibers(BFs),we propose a strategy for converting bamboo cells into FSEs using conductive BFs and activated PCs as current collectors and active materials,respectively.The assembled electrode has a high specific capacitance of 1454 mF cm^(−2) at 0.64 mA cm^(−2).A solid-state FSC with a pair of bamboo-structured electrodes exhibited a substantially high energy density.Its mechanical flexibility enabled the knitting of wearable wristbands to drive ultra-small voltmeter indicators.This lightweight,low cost,and high-energy-density bamboostructured FSC could enable numerous smart textile applications.
基金supported by the Ministry of Science and Technology(MOST)of China through the Key Project of Research&Development(2021YFF0500502)。
文摘Oxygen defects play a critical role in the electrocatalytic oxygen evolution reaction(OER).Therefore,in-depth understanding the structure-activity-mechanism relationship of these defects is the key to design efficient OER electrocatalysts.This relationship needs to be understood dynamically due to the potential for irreversible phase transitions during OER.Consequently,significant efforts have been devoted to study the dynamic evolution of oxygen defects to shed light on the OER mechanism.This review critically examines and analyzes the dynamic processes occurring at oxygen defect sites during OER,including defect formation and defect evolution mechanisms,along with the advanced characterization techniques needed to understand these processes.This review aims to provide a comprehensive understanding of high-efficiency electrocatalysts,with a particular emphasis on the importance of in situ monitoring the dynamic evolution of oxygen defects,providing a new perspective towards efficient OER electrocatalyst design.
基金the National Natural Science Foundation of China(Nos.52302272 and 22376110)the Taishan Scholars Program(No.tsqn202211124)+2 种基金the Natural Science Foundation of Shandong Province(No.ZR2022QB023)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Innovation Team of Marine Polysaccharides Fibers-based Energy Materials)the State Key Laboratory of Bio-Fibers and Eco-Textiles,Qingdao University(Nos.ZKT10,GZRC202006,ZFZ201809,and ZDKT202105).
文摘Rationally constructed new catalyst can promote carbon dioxide reduction reaction(CO_(2)RR)to valuable carbo-naceous fuels such as formate and CO,providing a promising strategy for low CO_(2)emissions.Herein,the syn-thesized Ni_(3)S_(2)@C as a highly efficient electro-catalyst exhibits remarkable selectivity for formate with 73.9%faradaic efficiency(FE)at-0.7 V vs.RHE.At high applied potential,it shows a high syngas evolution with CO/H_(2)ratios(0.54-3.15)that are suitable for typical downstream thermochemical reactions.The experimental and theoretical analyses demonstrate that the electron-rich Ni^(2+)in Ni_(3)S_(2)enhances the adsorption behavior of*OCHO intermediate,reduces the energy barrier of the formation of intermediates,and improves the selectivity of the formate product.Attenuated total reflection surface-enhanced infrared absorption spectra conducted in situ show that*OCHO intermediate is more likely to be generated and adsorbed on Ni_(3)S_(2),enhancing the selectivity and activity of the formate product.
基金This research was funded by the National Natural Science Foundation of China(Grant Nos.51672143 and 51808303)Natural Science Foundation of Shandong Province(Nos.ZR2019BEE027 and ZR2018BEM002)+1 种基金Applied Basic Research of Qingdao City(Special Youth Project)(Nos.19-6-2-74-cg and 19-6-2-83-cg)Outstanding Youth of Natural Science in Shandong Province(No.JQ201713),and Taishan Scholars Program.
文摘Iron sulfide(FeS)nanoparticles(termed FSNs)have attracted much attention for the removal of pollutants due to their high efficiency and low cost,and because they are environmentally friendly.However,issues of agglomeration,transformation,and the loss of active components limit their application.Therefore,this study investigates in situ synthesized FeS/carbon fibers with an Fecarrageenan biomass as a precursor and nontoxic sulfur source to ascertain the removal efficiency of the fibers.The enrichment of sulfate groups as well as the double-helix structure in i-carrageenan-Fe could effectively avoid the aggregation and loss of FSNs in practical applications.The obtained FeS/carbon fibers were used to control a Cr(Ⅵ)polluted solution,and exhibited a relatively high removal capacity(81.62 mg/g).T he main mechanisms included the reduction of FeS,electrostatic adsorption of carbon fibers,and Cr(Ⅲ)-Fe(Ⅲ)complexation reaction.The pseudo-second-order kinetic model and Langmuir adsorption model both provided a good fit of the reaction process;hence,the removal process was mainly controlled by chemical adsorption,specifically monolayer adsorption on a uniform surface.Furthermore,co-existing anions,column,and regeneration experiments indicated that the FeS/carbon fibers are a promising remediation material for practical application.
基金This article was funded by National Natural Science Foundation of China(Grant nos.51672143,21805148,22075157,52102271).
文摘Developing low-cost,efficient oxygen reduction reaction(ORR)catalysts to replace Pt-based materials is urgently required for the application of Zn-air batteries(ZABs)and microbial fuel cells(MFCs).In this work,meso-microporous carbon fibers with tunable defect density were synthesized by carrageenan fibers.A highly defective carbon fiber(HDCFs)was produced which exhibited an outstanding ORR catalytic activity,reaching to the half-wave potential of 0.841 and 0.44 V in alkaline and neutral electrolytes,respectively.These HDCFs can also act as highly efficient air cathodes for ZABs(delivered potential of 0.69 V and power density of 220 mW cm^(–2) at 300 mA cm^(–2))and MFCs(high power density of 69.7 mW cm^(–2)).Simulation by the density functional theory indicated that a high density of defections in a carbon based framework can remarkably modulate the electrical properties.For instance the charge entrapments in the carbon active sites may reduce the energy barrier of ORR.
