The composite polymer electrolyte has been obtained via incorporating LiCUST-701(a new metal–organic rotaxane framework modified by Li+)into poly(ethylene oxide)(PEO)matrix and give a high ionic conductivity of 4.02&...The composite polymer electrolyte has been obtained via incorporating LiCUST-701(a new metal–organic rotaxane framework modified by Li+)into poly(ethylene oxide)(PEO)matrix and give a high ionic conductivity of 4.02×10^(−4)S/cm at 60℃.DFT calculations were used to visualize the possible diffusion pathway of Li+.The all-solid-state cell assembled with LiFePO_(4),composite polymer electrolyte and lithium metal foil delivered with excellent cycling capability and stability even under high current densities.展开更多
Efficient catalysis of the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is essential for the rechargeable zinc-air batteries(R-ZABs).However,challenges remain due to the scarcity of effective bifunc...Efficient catalysis of the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is essential for the rechargeable zinc-air batteries(R-ZABs).However,challenges remain due to the scarcity of effective bifunctional electrocatalysts and limited understanding of the structure-activity relationships.Pyrrole-type single-atom catalysts(SACs)with unique electronic structures have emerged as promising electrocatalysts.In this work,we combine density functional theory(DFT)calculations and experimental studies to systematically explore the structure-activity relationships and potential of pyrrole-type transition metal-N_(3)(TM-po-N_(3))as bifunctional catalysts.DFT calculations reveal that differences in the dependence of ORR and OER activities on the free energy of adsorption of reaction intermediates significantly affect the TM-po-N_(3)bifunctional activity and identify magnetic Cu-po-N_(3)as the best candidate.The bifunctional activity of Cu-po-N_(3)originates from interactions between spin-polarized out-of-plane Cu_3d and O_2s+2p orbitals.Theoretical predictions are validated experimentally,showing that the synthesized Cu-SAC/NC exhibits excellent bifunctional performance with a small potential gap of 0.666 V.Additionally,the assembled R-ZABs display a high-power density of 170 mW cm^(-2)and long-term stability,with the charge-discharge voltage gap increasing by only 0.01 V over 240 h.This work provides new insights into the design of efficient bifunctional catalysts.展开更多
Bismuth-based catalysts are highly promising for the electrochemical carbon dioxide reduction reaction(eCO_(2)RR)to formate product.However,achieving high activity and selectivity towards formate and ensuring long-ter...Bismuth-based catalysts are highly promising for the electrochemical carbon dioxide reduction reaction(eCO_(2)RR)to formate product.However,achieving high activity and selectivity towards formate and ensuring long-term stability remains challenging.This work reports the oxygen plasma inducing strategy to construct the abundant grain boundaries of Bi/BiO_x on ultrathin two-dimensional Bi nanosheets.The oxygen plasma-treated Bi nanosheet(OP-Bi)exhibits over 90%Faradaic efficiency(FE)for formate at a wide potential range from-0.5 to-1.1 V,and maintains a great stability catalytic performance without significant decay over 30 h in flow cell.Moreover,membrane electrode assembly(MEA)device with OPBi as catalyst sustains the robust current density of 100 mA cm^(-2)over 50 h,maintaining a formate FE above 90%.In addition,rechargeable Zn-CO_(2)battery presents the peak power density of1.22 mW cm^(-2)with OP-Bi as bifunctional catalyst.The mechanism experiments demonstrate that the high-density grain boundaries of OP-Bi provide more exposed active sites,faster electron transfer capacity,and the stronger intrinsic activity of Bi atoms.In situ spectroscopy and theo retical calculations further elucidate that the unsaturated Bi coordination atoms between the grain boundaries can effectively activate CO_(2)molecules through elongating the C-O bond,and reducing the formation energy barrier of the key intermediate(^(*)OCOH),thereby enhancing the catalytic performance of eCO_(2)RR to formate product.展开更多
MnNiGe：Fe ribbon samples are prepared. Partial Ni-and Mn-substitution of Fe element can both induce the antiferromagnetic-ferromagnetic conversion in the Ti Ni Si-type state of these MnNiGe：Fe ribbon systems. It is ...MnNiGe：Fe ribbon samples are prepared. Partial Ni-and Mn-substitution of Fe element can both induce the antiferromagnetic-ferromagnetic conversion in the Ti Ni Si-type state of these MnNiGe：Fe ribbon systems. It is found out, however, that some factors such as annealing, temperature variation process field-cycling, substituted site and magnetic field can affect the conversion and competition between the antiferromagnetic and ferromagnetic states in these ribbons. Therefore, in this paper these major influencing factors are studied systematically and further discussed are the related magnetic and magnetocaloric properties in MnNiGe：Fe ribbon systems.展开更多
Seawater electrolysis is an effective way to obtain hydrogen(H_(2))in a sustainable manner.However,the lack of electrocatalysts with high activity,stability,and selectivity for oxygen evolution reaction(OER)severely h...Seawater electrolysis is an effective way to obtain hydrogen(H_(2))in a sustainable manner.However,the lack of electrocatalysts with high activity,stability,and selectivity for oxygen evolution reaction(OER)severely hinders the development of seawater electrolysis technology.Herein,sulfur-doped nickel-iron selenide nanosheets(S-NiFeSe_(2))were prepared by an ion-exchange strategy and served as highly active OER electrocatalyst for alkaline seawater electrolysis.The overpotential is 367 m V,and it can run stably for over 50 h at 100 m A cm^(-2).Excitingly,the S-NiFeSe_(2)||Pt/C pair exhibits cell voltage of 1.54 V at 10 m A cm^(-2)under alkaline seawater conditions,which can run smoothly for 100 h without decay,and the efficiency of electricity-tohydrogen(ETH)energy conversion reaches more than 80%.Such electrode,with abundant accessible reactive sites and good corrosion resistance,is a good candidate for seawater electrolysis.Moreover,density functional theory calculations reveal that the surface sulfur atoms can activate the adjacent Ni sites and decrease the free energy changes of the associated intermediates at the adjacent Ni sites for OER,and the step of~*OH→~*O is the potential rate-limiting step.In this work,the true reactive site in nickel-iron selenides is the Ni sites,but not the Fe sites as commonly believed.展开更多
基金the National Natural Science Foundation of China(Nos.U1973201 and 22271023).
文摘The composite polymer electrolyte has been obtained via incorporating LiCUST-701(a new metal–organic rotaxane framework modified by Li+)into poly(ethylene oxide)(PEO)matrix and give a high ionic conductivity of 4.02×10^(−4)S/cm at 60℃.DFT calculations were used to visualize the possible diffusion pathway of Li+.The all-solid-state cell assembled with LiFePO_(4),composite polymer electrolyte and lithium metal foil delivered with excellent cycling capability and stability even under high current densities.
基金supported by the Hainan Province Science and Technology Special Fund(ZDYF2020037)the National Natural Science Foundation of China(22109035,52164028,52274297,22462006)+3 种基金the Postdoctoral Science Foundation of Hainan Province(RZ2100007123)the Basic and Applied Basic Research Foundation of Guangdong Province(2019A1515110558)the Start-up Research Foundation of Hainan University(KYQD(ZR)-20008,20083,20084,21125)Hainan University(XTCX2022HYC05)。
文摘Efficient catalysis of the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is essential for the rechargeable zinc-air batteries(R-ZABs).However,challenges remain due to the scarcity of effective bifunctional electrocatalysts and limited understanding of the structure-activity relationships.Pyrrole-type single-atom catalysts(SACs)with unique electronic structures have emerged as promising electrocatalysts.In this work,we combine density functional theory(DFT)calculations and experimental studies to systematically explore the structure-activity relationships and potential of pyrrole-type transition metal-N_(3)(TM-po-N_(3))as bifunctional catalysts.DFT calculations reveal that differences in the dependence of ORR and OER activities on the free energy of adsorption of reaction intermediates significantly affect the TM-po-N_(3)bifunctional activity and identify magnetic Cu-po-N_(3)as the best candidate.The bifunctional activity of Cu-po-N_(3)originates from interactions between spin-polarized out-of-plane Cu_3d and O_2s+2p orbitals.Theoretical predictions are validated experimentally,showing that the synthesized Cu-SAC/NC exhibits excellent bifunctional performance with a small potential gap of 0.666 V.Additionally,the assembled R-ZABs display a high-power density of 170 mW cm^(-2)and long-term stability,with the charge-discharge voltage gap increasing by only 0.01 V over 240 h.This work provides new insights into the design of efficient bifunctional catalysts.
基金supported by the Hainan Province Science and Technology Special Fund(ZDYF2024SHFZ074,ZDYF2024SHFZ072,ZDYF2022SHFZ299)the National Natural Science Foundation of China(22109035,22202053,52164028,52274297,22309037)+4 种基金the Start-up Research Foundation of Hainan University(KYQD(ZR)-20008,20083,20084,21125,23035)the collaborative Innovation Center of Marine Science and Technology,Hainan University(XTCX2022HYC04,XTCX2022HYC05)the Innovative Research Projects for Graduate Students of Hainan Province(Qhyb2022-89,Qhyb2022-87,Qhys2022-174)the Scientific Research Program Funded by Shaanxi Provincial Education Department(Program No.23JK0439)the specific research fund of The Innovation Platform for Academicians of Hainan Province(YSPTZX202315)。
文摘Bismuth-based catalysts are highly promising for the electrochemical carbon dioxide reduction reaction(eCO_(2)RR)to formate product.However,achieving high activity and selectivity towards formate and ensuring long-term stability remains challenging.This work reports the oxygen plasma inducing strategy to construct the abundant grain boundaries of Bi/BiO_x on ultrathin two-dimensional Bi nanosheets.The oxygen plasma-treated Bi nanosheet(OP-Bi)exhibits over 90%Faradaic efficiency(FE)for formate at a wide potential range from-0.5 to-1.1 V,and maintains a great stability catalytic performance without significant decay over 30 h in flow cell.Moreover,membrane electrode assembly(MEA)device with OPBi as catalyst sustains the robust current density of 100 mA cm^(-2)over 50 h,maintaining a formate FE above 90%.In addition,rechargeable Zn-CO_(2)battery presents the peak power density of1.22 mW cm^(-2)with OP-Bi as bifunctional catalyst.The mechanism experiments demonstrate that the high-density grain boundaries of OP-Bi provide more exposed active sites,faster electron transfer capacity,and the stronger intrinsic activity of Bi atoms.In situ spectroscopy and theo retical calculations further elucidate that the unsaturated Bi coordination atoms between the grain boundaries can effectively activate CO_(2)molecules through elongating the C-O bond,and reducing the formation energy barrier of the key intermediate(^(*)OCOH),thereby enhancing the catalytic performance of eCO_(2)RR to formate product.
基金the National Natural Science Foundation of China (Grant Nos. 51261022, 51561023 and 51671097)the Jiangxi Provincial Graduate Student Innovation Special Funds Project (Grant No. YC2015-S310)the Graduate Student Innovation Special Funds Project of Nanchang Hangkong University (Grant No. YC2015007)
文摘MnNiGe：Fe ribbon samples are prepared. Partial Ni-and Mn-substitution of Fe element can both induce the antiferromagnetic-ferromagnetic conversion in the Ti Ni Si-type state of these MnNiGe：Fe ribbon systems. It is found out, however, that some factors such as annealing, temperature variation process field-cycling, substituted site and magnetic field can affect the conversion and competition between the antiferromagnetic and ferromagnetic states in these ribbons. Therefore, in this paper these major influencing factors are studied systematically and further discussed are the related magnetic and magnetocaloric properties in MnNiGe：Fe ribbon systems.
基金supported by the National Natural Science Foundation of China(22202053,22109035,52274297)the Startup Research Foundation of Hainan University(KYQD(ZR)-20008,20083,20084,21125,23170)+3 种基金the specific research fund of the Innovation Platform for Academicians of Hainan Province(YSPTZX202315)the Research Fund Program of Guangdong Provincial Key Laboratory of Fuel Cell Technology(FC202307)the Open Fund Project of Key Laboratory of Electrochemical Energy Storage and Energy Conversion in Hainan Province of China(KFKT2023002)the Innovative Research Projects for Graduate Students of Hainan Province(Qhyb2023-15)。
文摘Seawater electrolysis is an effective way to obtain hydrogen(H_(2))in a sustainable manner.However,the lack of electrocatalysts with high activity,stability,and selectivity for oxygen evolution reaction(OER)severely hinders the development of seawater electrolysis technology.Herein,sulfur-doped nickel-iron selenide nanosheets(S-NiFeSe_(2))were prepared by an ion-exchange strategy and served as highly active OER electrocatalyst for alkaline seawater electrolysis.The overpotential is 367 m V,and it can run stably for over 50 h at 100 m A cm^(-2).Excitingly,the S-NiFeSe_(2)||Pt/C pair exhibits cell voltage of 1.54 V at 10 m A cm^(-2)under alkaline seawater conditions,which can run smoothly for 100 h without decay,and the efficiency of electricity-tohydrogen(ETH)energy conversion reaches more than 80%.Such electrode,with abundant accessible reactive sites and good corrosion resistance,is a good candidate for seawater electrolysis.Moreover,density functional theory calculations reveal that the surface sulfur atoms can activate the adjacent Ni sites and decrease the free energy changes of the associated intermediates at the adjacent Ni sites for OER,and the step of~*OH→~*O is the potential rate-limiting step.In this work,the true reactive site in nickel-iron selenides is the Ni sites,but not the Fe sites as commonly believed.
