Improving the OER activity of noble metal-based materials is of profound importance to minimize the usage of noble metals and lower the cost.Here,we report considerable improvement on the catalytic activity of RuO_(2)...Improving the OER activity of noble metal-based materials is of profound importance to minimize the usage of noble metals and lower the cost.Here,we report considerable improvement on the catalytic activity of RuO_(2) particles for OER in both alkali and acid environments.The RuO_(2) nanoparticles were treated with a method of pulse laser ablation.Numerous Ru and RuO_(2) clusters were generated at the surface of RuO_(2) nanoparticles after the laser ablation,forming a lychee-shaped morphology.The larger pulse energy RuO_(2) nanoparticles are treated with,the better the OER activity can be.DFT calculations shows that the surface tension induced by the lychee-shaped morphology benefits the OER performance.Our best sample gives an overpotential of 172 mV(at 10 mA cm^(-2))and a Tafel slope of 53.5 mV dec^(-1) in KOH,while an overpotential of 219 mV and a Tafel slope of 44.9 mV dec^(-1) in H_(2)SO_(4),which are of topclass results.This work may inspire a new way to develop high-performance electrocatalysts for OER.展开更多
The nature of the Cooper pairing in the paradigmatic unconventional superconductor Sr_(2)RuO_(4) is an outstanding puzzle in condensed matter physics.Despite the tremendous efforts made in the past twenty-seven years,...The nature of the Cooper pairing in the paradigmatic unconventional superconductor Sr_(2)RuO_(4) is an outstanding puzzle in condensed matter physics.Despite the tremendous efforts made in the past twenty-seven years,neither the pairing symmetry nor the underlying pairing mechanism in this material has been understood with clear consensus.This is largely due to the lack of a superconducting order that is capable of interpreting in a coherent manner the numerous essential experimental observations.At this stage,it may be desirable to reexamine our existing theoretical descriptions of superconducting Sr_(2)RuO_(4).This review focuses on several recent developments that may provide some clues for future study.We highlight three separate aspects:1)any pairing in the Eu symmetry channel,with which the widely discussed chiral p-wave is associated,shall acquire a 3D structure due to spin-orbit entanglement;2)if the reported Kerr effect is a superconductivity-induced intrinsic bulk response,the superconductivity must either exhibit a chiral character,or be complex mixtures of certain set of helical p-wave pairings;3)when expressed in a multiorbital basis,the Cooper pairing could acquire numerous exotic forms that are inaccessible in single-orbital descriptions.The implications of each of these new perspectives are briefly discussed in connection with selected experimental phenomena.展开更多
Efficiently reducing carbon dioxide(CO_(2))into carbon chemicals and fuels is highly desirable due to the rapid growth of atmospheric CO_(2)ncentration.In prior work,we described a unique H/CO_(2)fuel cell driven by l...Efficiently reducing carbon dioxide(CO_(2))into carbon chemicals and fuels is highly desirable due to the rapid growth of atmospheric CO_(2)ncentration.In prior work,we described a unique H/CO_(2)fuel cell driven by low-valued waste heat,which not only CO_(2)nverts CO_(2)to methane(CH_(4))but also outputs electrical energy,yet the CO_(2)reduction rate needs to be urgently improved.Here,a novel Ru-RuOcatalyst with heterostructure was grafted on mesoporous carbon spheres by in situ partially reducing RuOinto ultrasmall Ru clusters(~1 nm),in which heteroatom-doped carbon spheres as a matrix with excellent CO_(2)nductivity and abundant pores can not only easily CO_(2)nfine the formation of Ru nanocluster but also are beneficial to the exposed active sites of Ru CO_(2)mplex and the mass transport.CO_(2)mpared to pure RuOnanoparticles supported on carbon spheres,our CO_(2)mposite catalyst boosts the CO_(2) nversion rate by more than 5-fold,reaching a value of 382.7μmol gcat.h-1at 170℃.Moreover,a decent output power density of 2.92 W mwas obtained from this H2/CO_(2)fuel cell using Ru-RuOembedded carbon spheres as a cathode catalyst.The Ru-RuOheterostructure can modify the adsorption energy of CO_(2)and induce the redistribution of charge density,thus boosting CO_(2)reduction significantly.This work not only offers an efficient catalyst for this novel H_(2)/CO_(2)fuel cell but also presents a facile method to prepare Ru nanoclusters.展开更多
基金the financial support from the Key Research and Development of Ministry of Science and Technology of China(No.2018YFE0202600)National Natural Science Foundation of China(No.11947070,No.51902220,No.51572183)+1 种基金Materials Science&Engineering of Zhejiang Province First-Class Discipline(No.P61021902)Cultivating Program of Taizhou University(No.2018PY050)。
文摘Improving the OER activity of noble metal-based materials is of profound importance to minimize the usage of noble metals and lower the cost.Here,we report considerable improvement on the catalytic activity of RuO_(2) particles for OER in both alkali and acid environments.The RuO_(2) nanoparticles were treated with a method of pulse laser ablation.Numerous Ru and RuO_(2) clusters were generated at the surface of RuO_(2) nanoparticles after the laser ablation,forming a lychee-shaped morphology.The larger pulse energy RuO_(2) nanoparticles are treated with,the better the OER activity can be.DFT calculations shows that the surface tension induced by the lychee-shaped morphology benefits the OER performance.Our best sample gives an overpotential of 172 mV(at 10 mA cm^(-2))and a Tafel slope of 53.5 mV dec^(-1) in KOH,while an overpotential of 219 mV and a Tafel slope of 44.9 mV dec^(-1) in H_(2)SO_(4),which are of topclass results.This work may inspire a new way to develop high-performance electrocatalysts for OER.
基金supported by the National Natural Science Foundation of China(Grant No.11904155)the Guangdong Provincial Key Laboratory(Grant No.2019B121203002)a Shenzhen Science and Technology Program(Grant No.KQTD20200820113010023).
文摘The nature of the Cooper pairing in the paradigmatic unconventional superconductor Sr_(2)RuO_(4) is an outstanding puzzle in condensed matter physics.Despite the tremendous efforts made in the past twenty-seven years,neither the pairing symmetry nor the underlying pairing mechanism in this material has been understood with clear consensus.This is largely due to the lack of a superconducting order that is capable of interpreting in a coherent manner the numerous essential experimental observations.At this stage,it may be desirable to reexamine our existing theoretical descriptions of superconducting Sr_(2)RuO_(4).This review focuses on several recent developments that may provide some clues for future study.We highlight three separate aspects:1)any pairing in the Eu symmetry channel,with which the widely discussed chiral p-wave is associated,shall acquire a 3D structure due to spin-orbit entanglement;2)if the reported Kerr effect is a superconductivity-induced intrinsic bulk response,the superconductivity must either exhibit a chiral character,or be complex mixtures of certain set of helical p-wave pairings;3)when expressed in a multiorbital basis,the Cooper pairing could acquire numerous exotic forms that are inaccessible in single-orbital descriptions.The implications of each of these new perspectives are briefly discussed in connection with selected experimental phenomena.
基金financially supported by the Natural Science Foundation of Shaanxi Provincial(2021JQ-034)Chongqing University Key Laboratory of Micro/Nano Materials Engineering and Technology(KFJJ2012)by University Joint Project of Shaanxi Province(2021GXLH-Z-067)。
文摘Efficiently reducing carbon dioxide(CO_(2))into carbon chemicals and fuels is highly desirable due to the rapid growth of atmospheric CO_(2)ncentration.In prior work,we described a unique H/CO_(2)fuel cell driven by low-valued waste heat,which not only CO_(2)nverts CO_(2)to methane(CH_(4))but also outputs electrical energy,yet the CO_(2)reduction rate needs to be urgently improved.Here,a novel Ru-RuOcatalyst with heterostructure was grafted on mesoporous carbon spheres by in situ partially reducing RuOinto ultrasmall Ru clusters(~1 nm),in which heteroatom-doped carbon spheres as a matrix with excellent CO_(2)nductivity and abundant pores can not only easily CO_(2)nfine the formation of Ru nanocluster but also are beneficial to the exposed active sites of Ru CO_(2)mplex and the mass transport.CO_(2)mpared to pure RuOnanoparticles supported on carbon spheres,our CO_(2)mposite catalyst boosts the CO_(2) nversion rate by more than 5-fold,reaching a value of 382.7μmol gcat.h-1at 170℃.Moreover,a decent output power density of 2.92 W mwas obtained from this H2/CO_(2)fuel cell using Ru-RuOembedded carbon spheres as a cathode catalyst.The Ru-RuOheterostructure can modify the adsorption energy of CO_(2)and induce the redistribution of charge density,thus boosting CO_(2)reduction significantly.This work not only offers an efficient catalyst for this novel H_(2)/CO_(2)fuel cell but also presents a facile method to prepare Ru nanoclusters.
