The development of highly active and easily coupled non-noble metal electrocatalysts for oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)is of great significance for the H_(2) production by water ele...The development of highly active and easily coupled non-noble metal electrocatalysts for oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)is of great significance for the H_(2) production by water electrolysis.Here,we have shown an anion-modulated HER and OER activity of 1D Co-Mo based interstitial compound heterojunctions for effective overall water splitting.The Co-Mo based complex nanowires from a one-pot route with high yields can be converted into MoC-Co heterojunction nanowires under N_(2) atmosphere,while a pyrolysis under NH_(3) can give CoMoN-CoN heterostructures.The work function revealed Mott-Schottky effect between interfaces of two heterostructures,which can introduce electron redistribution and thus promote the HER/OER process.The MoC-Co heterojunction nanowires delivers good HER activity at a low overpotential of 39mV to afford a current density of 10mA/cm^(2).Density functional theory calculations show that the heterogeneous interface formed between the Co and MoC optimizes the hydrogen adsorption free energy.Concurrently,CoMoN-CoN heterojunction nanowires exhibits good OER performance with a low overpotential of 260mV to reach 10mA/cm^(2),being superior to RuO_(2).The two catalysts can be coupled to assemble a two-electrode cell with a solarto-hydrogen efficiency of 12.3%at 1.54 V.This work provides an effective means to design easily coupled HER and OER catalysts for H_(2) production by water electrolysis.展开更多
The rational construction of high-performance and stable electrocatalyst for oxygen evolution reaction(OER)is a prerequisite for efficient water electrolysis.Herein,we develop a broccoli-like Ni_(3)S_(2)@NiFeP_(x)(Ni_...The rational construction of high-performance and stable electrocatalyst for oxygen evolution reaction(OER)is a prerequisite for efficient water electrolysis.Herein,we develop a broccoli-like Ni_(3)S_(2)@NiFeP_(x)(Ni_(3)S_(2)@NFP)catalyst on nickel foam(NF)via a sequential two-step layer-by-layer assembly electrodeposition method.X-ray diffraction,in situ Raman and Fourier-transform infrared spectra have mutually validated the element segregation and phase refusion during OER condition.The reconstruction of double layer Ni_(3)S_(2)@NFP facilitates the formation of the active(oxy)hydroxides,which is modulated by the dual anionic layer with mixed sulfate and phosphate ions.As a result,the obtained Ni_(3)S_(2)@NFP electrode exhibits low overpotential(329 mV)and long-term durability(∼500 h)for OER at current density of 500mA/cm^(2).Moreover,the self-supported Ni_(3)S_(2)@NFP can act as an efficient and durable anode in alkaline anion exchange membrane water electrolysis device(AEMWE).This work provides a facile and scaled-up strategy to construct self-supported electrocatalyst and emphasizes the crucial role of anions in pre-catalyst reconstruction and enhancing OER performance.展开更多
基金support of this research by the National Natural Science Foundation of China(No.91961111)the Natural Science Foundation of Heilongjiang Province(No.ZD2021B003)Fundamental Research Funds for the Central Universities(No.2572022BU05).
文摘The development of highly active and easily coupled non-noble metal electrocatalysts for oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)is of great significance for the H_(2) production by water electrolysis.Here,we have shown an anion-modulated HER and OER activity of 1D Co-Mo based interstitial compound heterojunctions for effective overall water splitting.The Co-Mo based complex nanowires from a one-pot route with high yields can be converted into MoC-Co heterojunction nanowires under N_(2) atmosphere,while a pyrolysis under NH_(3) can give CoMoN-CoN heterostructures.The work function revealed Mott-Schottky effect between interfaces of two heterostructures,which can introduce electron redistribution and thus promote the HER/OER process.The MoC-Co heterojunction nanowires delivers good HER activity at a low overpotential of 39mV to afford a current density of 10mA/cm^(2).Density functional theory calculations show that the heterogeneous interface formed between the Co and MoC optimizes the hydrogen adsorption free energy.Concurrently,CoMoN-CoN heterojunction nanowires exhibits good OER performance with a low overpotential of 260mV to reach 10mA/cm^(2),being superior to RuO_(2).The two catalysts can be coupled to assemble a two-electrode cell with a solarto-hydrogen efficiency of 12.3%at 1.54 V.This work provides an effective means to design easily coupled HER and OER catalysts for H_(2) production by water electrolysis.
基金supported by the National Natural Science Foundation of China(NSFC,Nos.21925503,22102076)the Ministry of Science and Technology of the People’s Republic of China(MOST,No.2022YFA1504001)+1 种基金the Ministry of Education of the People’s Republic of China(MOE,No.B12015)the Fundamental Research Funds for the Central Universities.
文摘The rational construction of high-performance and stable electrocatalyst for oxygen evolution reaction(OER)is a prerequisite for efficient water electrolysis.Herein,we develop a broccoli-like Ni_(3)S_(2)@NiFeP_(x)(Ni_(3)S_(2)@NFP)catalyst on nickel foam(NF)via a sequential two-step layer-by-layer assembly electrodeposition method.X-ray diffraction,in situ Raman and Fourier-transform infrared spectra have mutually validated the element segregation and phase refusion during OER condition.The reconstruction of double layer Ni_(3)S_(2)@NFP facilitates the formation of the active(oxy)hydroxides,which is modulated by the dual anionic layer with mixed sulfate and phosphate ions.As a result,the obtained Ni_(3)S_(2)@NFP electrode exhibits low overpotential(329 mV)and long-term durability(∼500 h)for OER at current density of 500mA/cm^(2).Moreover,the self-supported Ni_(3)S_(2)@NFP can act as an efficient and durable anode in alkaline anion exchange membrane water electrolysis device(AEMWE).This work provides a facile and scaled-up strategy to construct self-supported electrocatalyst and emphasizes the crucial role of anions in pre-catalyst reconstruction and enhancing OER performance.
