Replacing traditional polymer-based precursors with small molecules is a promising pathway toward facile and controllable preparation of porous carbons but remains a prohibitive challenge because of the high volatilit...Replacing traditional polymer-based precursors with small molecules is a promising pathway toward facile and controllable preparation of porous carbons but remains a prohibitive challenge because of the high volatility of small molecules.Herein,a simple,general,and controllable method is reported to prepare porous carbons by converting small organic molecules into organic molecular salts followed by pyrolysis.The robust electrostatic force holding organic molecular salts together leads to negligible volatility and thus ensures the formation of carbons under high-temperature pyrolysis.Meanwhile,metal moieties in organic molecular salts can be evolved into in-situ templates or activators during pyrolysis to create nanopores.The modular nature of organic molecular salts allows easy control of the porosity and chemical doping of carbons at a molecular level.The sulfur-doped carbon prepared by the ionic solid strategy can serve as robust support to prepare small-sized intermetallic PtCo catalysts,which exhibit a high mass activity of 1.62 A·mgPt^(−1)in catalyzing oxygen reduction reaction for fuel cell applications.展开更多
Lanthanum strontium cobalt ferrite(LSCF)is an appreciable cathode material for solid oxide fuel cells(SOFCs),and it has been widely investigated,owing to its excellent thermal and chemical stability.However,its poor o...Lanthanum strontium cobalt ferrite(LSCF)is an appreciable cathode material for solid oxide fuel cells(SOFCs),and it has been widely investigated,owing to its excellent thermal and chemical stability.However,its poor oxygen reduction reaction(ORR)activity,particularly at a temperature of≤800℃,causes setbacks in achieving a peak power density of>1.0 W·cm^(-2),limiting its application in the commercialization of SOFCs.To improve the ORR of LSCF,doping strategies have been found useful.Herein,the porous tantalum-doped LSCF materials(La_(0.6)Sr_(0.4)Co_(0.4)Fe_(0.5)7Ta_(0.03)O_(3)(LSCFT-0),La_(0.6)Sr_(0.4)Co_(0.4)Fe_(0.5)4Ta0.06O_(3),and La_(0.6)Sr_(0.4)Co_(0.4)Fe_(0.5)Ta0.1O_(3))are prepared via camphor-assisted solid-state reaction(CSSR).The LSCFT-0 material exhibits promising ORR with area-specific resistance(ASR)of 1.260,_(0.5)80,0.260,0.100,and 0.06Ω·cm^(2)at 600,650,700,750,and 800℃,respectively.The performance is about 2 times higher than that of undoped La_(0.6)Sr_(0.4)Co_(0.4)Fe_(0.6)O_(3)with the ASR of 2.515,1.191,_(0.5)96,0.320,and 0.181Ω·cm^(2)from the lowest to the highest temperature.Through material characterization,it was found that the incorporated Ta occupied the B-site of the material,leading to the enhancement of the ORR activity.With the use of LSCFT-0 as the cathode material for anode-supported single-cell,the power density of>1.0 W·cm^(-2)was obtained at a temperature<800℃.The results indicate that the CSSR-derived LSCFT is a promising cathode material for SOFCs.展开更多
Semiconductors and the associated methodologies applied to electrochemistry have recently grown as an emerging field in energy materials and technologies.For example,semiconductor membranes and heterostructure fuel ce...Semiconductors and the associated methodologies applied to electrochemistry have recently grown as an emerging field in energy materials and technologies.For example,semiconductor membranes and heterostructure fuel cells are new technological trend,which differ from the traditional fuel cell electrochemistry principle employing three basic functional components:anode,electrolyte,and cathode.The electrolyte is key to the device performance by providing an ionic charge flow pathway between the anode and cathode while preventing electron passage.In contrast,semiconductors and derived heterostructures with electron(hole)conducting materials have demonstrated to be much better ionic conductors than the conventional ionic electrolytes.The energy band structure and alignment,band bending and built-in electric field are all important elements in this context to realize the necessary fuel cell functionalities.This review further extends to semiconductor-based electrochemical energy conversion and storage,describing their fundamentals and working principles,with the intention of advancing the understanding of the roles of semiconductors and energy bands in electrochemical devices for energy conversion and storage,as well as applications to meet emerging demands widely involved in energy applications,such as photocatalysis/water splitting devices,batteries and solar cells.This review provides new ideas and new solutions to problems beyond the conventional electrochemistry and presents new interdisciplinary approaches to develop clean energy conversion and storage technologies.展开更多
基金We acknowledge the funding support from the National Key Research and Development Program of China(No.2018YFA0702001)the National Natural Science Foundation of China(No.22071225)+6 种基金the Fundamental Research Funds for the Central Universities(No.WK2060190103)the Joint Funds from Hefei National Synchrotron Radiation Laboratory(No.KY2060000175)the Natural Science Foundation of Guangdong Province(No.2021A1515012356)the Research Grant for Scientific Platform and Project of Guangdong Provincial Education office(No.2019KTSCX151)Shenzhen Government’s Plan of Science and Technology(No.JCYJ20180305125247308)the Collaborative Innovation Program of Hefei Science Center of CAS(No.2021HSC-CIP015)L.D.F.acknowledges the support from the Instrumental Analysis Center of Shenzhen University(Xili Campus).
文摘Replacing traditional polymer-based precursors with small molecules is a promising pathway toward facile and controllable preparation of porous carbons but remains a prohibitive challenge because of the high volatility of small molecules.Herein,a simple,general,and controllable method is reported to prepare porous carbons by converting small organic molecules into organic molecular salts followed by pyrolysis.The robust electrostatic force holding organic molecular salts together leads to negligible volatility and thus ensures the formation of carbons under high-temperature pyrolysis.Meanwhile,metal moieties in organic molecular salts can be evolved into in-situ templates or activators during pyrolysis to create nanopores.The modular nature of organic molecular salts allows easy control of the porosity and chemical doping of carbons at a molecular level.The sulfur-doped carbon prepared by the ionic solid strategy can serve as robust support to prepare small-sized intermetallic PtCo catalysts,which exhibit a high mass activity of 1.62 A·mgPt^(−1)in catalyzing oxygen reduction reaction for fuel cell applications.
基金This work is supported by the National Natural Science Foundation of China(No.51975384)Guangdong Basic and Applied Basic Research Foundation(No.2020A1515011547)Shenzhen Fundamental Research Project(Nos.JCYJ20190808144009478,20200731211324001).
文摘Lanthanum strontium cobalt ferrite(LSCF)is an appreciable cathode material for solid oxide fuel cells(SOFCs),and it has been widely investigated,owing to its excellent thermal and chemical stability.However,its poor oxygen reduction reaction(ORR)activity,particularly at a temperature of≤800℃,causes setbacks in achieving a peak power density of>1.0 W·cm^(-2),limiting its application in the commercialization of SOFCs.To improve the ORR of LSCF,doping strategies have been found useful.Herein,the porous tantalum-doped LSCF materials(La_(0.6)Sr_(0.4)Co_(0.4)Fe_(0.5)7Ta_(0.03)O_(3)(LSCFT-0),La_(0.6)Sr_(0.4)Co_(0.4)Fe_(0.5)4Ta0.06O_(3),and La_(0.6)Sr_(0.4)Co_(0.4)Fe_(0.5)Ta0.1O_(3))are prepared via camphor-assisted solid-state reaction(CSSR).The LSCFT-0 material exhibits promising ORR with area-specific resistance(ASR)of 1.260,_(0.5)80,0.260,0.100,and 0.06Ω·cm^(2)at 600,650,700,750,and 800℃,respectively.The performance is about 2 times higher than that of undoped La_(0.6)Sr_(0.4)Co_(0.4)Fe_(0.6)O_(3)with the ASR of 2.515,1.191,_(0.5)96,0.320,and 0.181Ω·cm^(2)from the lowest to the highest temperature.Through material characterization,it was found that the incorporated Ta occupied the B-site of the material,leading to the enhancement of the ORR activity.With the use of LSCFT-0 as the cathode material for anode-supported single-cell,the power density of>1.0 W·cm^(-2)was obtained at a temperature<800℃.The results indicate that the CSSR-derived LSCFT is a promising cathode material for SOFCs.
基金the National Natural Science Foundation of China(51772080,51672208,51774259,and 51402093)the Natural Science Foundation of Guangdong Province(2021A1515012356 and 2017A030313289)+4 种基金the project foundation from the Ministry of Education of Guangdong Province(2019KTSCX151)Shenzhen Government Plan of Science and Technology(JCYJ20180305125247308)the National Laboratory of Solid State Microstructures,Nanjing University,EPSRC(EP/I013229/1)Royal Society and Newton Fund(NAF\R1\191294)Key Program for International S&T Cooperation Projects of Shaanxi Province(2019JZ-20,2019KWZ-03)。
文摘Semiconductors and the associated methodologies applied to electrochemistry have recently grown as an emerging field in energy materials and technologies.For example,semiconductor membranes and heterostructure fuel cells are new technological trend,which differ from the traditional fuel cell electrochemistry principle employing three basic functional components:anode,electrolyte,and cathode.The electrolyte is key to the device performance by providing an ionic charge flow pathway between the anode and cathode while preventing electron passage.In contrast,semiconductors and derived heterostructures with electron(hole)conducting materials have demonstrated to be much better ionic conductors than the conventional ionic electrolytes.The energy band structure and alignment,band bending and built-in electric field are all important elements in this context to realize the necessary fuel cell functionalities.This review further extends to semiconductor-based electrochemical energy conversion and storage,describing their fundamentals and working principles,with the intention of advancing the understanding of the roles of semiconductors and energy bands in electrochemical devices for energy conversion and storage,as well as applications to meet emerging demands widely involved in energy applications,such as photocatalysis/water splitting devices,batteries and solar cells.This review provides new ideas and new solutions to problems beyond the conventional electrochemistry and presents new interdisciplinary approaches to develop clean energy conversion and storage technologies.