Exploring highly efficient,economical and environment friendly electrocatalysts for the hydrogen and oxygen evolution reactions(HER and OER)is necessary but challenging for economical water splitting.Herein,FeS_(2) na...Exploring highly efficient,economical and environment friendly electrocatalysts for the hydrogen and oxygen evolution reactions(HER and OER)is necessary but challenging for economical water splitting.Herein,FeS_(2) nanoparticles were anchored on the surface of MXene through a simple adsorption-growth route(FeS_(2)@MXene).By virtue of the large active surface area of FeS_(2) and its robust interfacial interaction with conductive and hydrophilic MXene nanosheets,the obtained FeS_(2)@MXene composite can accelerate the transfer of mass/charge and facilitate contact between water molecules and reactive sites of FeS_(2).Specifically,MXene as a support material can not only alter the electrophilicity of the active centers of FeS_(2) through modulating the electron density but also prevent the aggregation of FeS_(2),thereby promoting activity and stability.The optimized FeS_(2)@MXene delivers a 10 mA cm-2 current density at overpotentials of 87 and 240 mV in alkaline solution for the HER and OER,respectively,which is comparable with reported transition metal sulfide(TMS)based catalysts.More importantly,in situ Raman spectroscopy reveals that the FeOOH generated during the OER process as a actual active species enhances the intrinsic activity of the catalyst.This work paves a new way for the interface engineering of TMS-based electrocatalysts towards water splitting.展开更多
The synergistic interaction between metal-organic frameworks(MOFs)and transition metal sulfides(TMS)has been a research hotspot in the field of electrocatalytic water splitting.Herein,nickel sulfide quantum dots@NiFe-...The synergistic interaction between metal-organic frameworks(MOFs)and transition metal sulfides(TMS)has been a research hotspot in the field of electrocatalytic water splitting.Herein,nickel sulfide quantum dots@NiFe-terephthalic acid nanosheet(NSQDs@NiFe-TPA)composites were prepared by a two-step hydrothermal method.The size and crystal structure of nickel sulfides were easily modulated by adjusting the concentration of the sulfurizing agent.The in situ formed NiS/Ni_(3)S_(2)quantum dots with grain sizes of around 5 nm were evenly dispersed on the surface of NiFe-TPA nanosheets,and the overpotential was only 219 mV at 10 mA cm^(-2),and 90%current density could be maintained at 1.5 V(vs.RHE)for 60 h.When the concentration of the sulfurizing agent was increased up to 0.15 mmol L^(-1),the as-prepared Ni_(3)S_(2)@NiFe-TPA exhibited an excellent HER performance.The overpotential is only 109 mV to reach a current density of 10 mA cm^(-2),and it was attenuated by 20 mV after a 60 h stability test at a current density of 20 mA cm^(-2).Furthermore,the overall water-splitting electrolyzer assembled with NSQDs@NiFe-TPA and Ni_(3)S_(2)@NiFe-TPA as anodic and cathodic electrodes exhibited a low cell voltage of 1.66 V at a current density 10 mA cm^(-2),and almost no attenuation was observed after a 60 h stability test.The outstanding electrocatalytic properties of the as-prepared catalyst are due to the synergy of nickel sulfides and 2D MOFs that offers abundant accessible active sites,rapid ion/electron transportation,and convenient O_(2)/H_(2)release channels.展开更多
基金supported by the National Natural Science Foundation of China[51871119,51901100 and 22075141]the High-Level Entrepreneurial and Innovative Talents Program of Jiangsu Province,the Six Talent Peak Project of Jiangsu Province[2018-XCL-033]+1 种基金the China Postdoctoral Science Foundation[2018M640481 and 2019T120426]the Jiangsu Postdoctoral Research Fund[2019K003].
文摘Exploring highly efficient,economical and environment friendly electrocatalysts for the hydrogen and oxygen evolution reactions(HER and OER)is necessary but challenging for economical water splitting.Herein,FeS_(2) nanoparticles were anchored on the surface of MXene through a simple adsorption-growth route(FeS_(2)@MXene).By virtue of the large active surface area of FeS_(2) and its robust interfacial interaction with conductive and hydrophilic MXene nanosheets,the obtained FeS_(2)@MXene composite can accelerate the transfer of mass/charge and facilitate contact between water molecules and reactive sites of FeS_(2).Specifically,MXene as a support material can not only alter the electrophilicity of the active centers of FeS_(2) through modulating the electron density but also prevent the aggregation of FeS_(2),thereby promoting activity and stability.The optimized FeS_(2)@MXene delivers a 10 mA cm-2 current density at overpotentials of 87 and 240 mV in alkaline solution for the HER and OER,respectively,which is comparable with reported transition metal sulfide(TMS)based catalysts.More importantly,in situ Raman spectroscopy reveals that the FeOOH generated during the OER process as a actual active species enhances the intrinsic activity of the catalyst.This work paves a new way for the interface engineering of TMS-based electrocatalysts towards water splitting.
基金financially supported by the National Key R&D Program of China(Project No.2021YFE0104700)the Science and Technology Development Fund of Egypt(Project No.43149)。
文摘The synergistic interaction between metal-organic frameworks(MOFs)and transition metal sulfides(TMS)has been a research hotspot in the field of electrocatalytic water splitting.Herein,nickel sulfide quantum dots@NiFe-terephthalic acid nanosheet(NSQDs@NiFe-TPA)composites were prepared by a two-step hydrothermal method.The size and crystal structure of nickel sulfides were easily modulated by adjusting the concentration of the sulfurizing agent.The in situ formed NiS/Ni_(3)S_(2)quantum dots with grain sizes of around 5 nm were evenly dispersed on the surface of NiFe-TPA nanosheets,and the overpotential was only 219 mV at 10 mA cm^(-2),and 90%current density could be maintained at 1.5 V(vs.RHE)for 60 h.When the concentration of the sulfurizing agent was increased up to 0.15 mmol L^(-1),the as-prepared Ni_(3)S_(2)@NiFe-TPA exhibited an excellent HER performance.The overpotential is only 109 mV to reach a current density of 10 mA cm^(-2),and it was attenuated by 20 mV after a 60 h stability test at a current density of 20 mA cm^(-2).Furthermore,the overall water-splitting electrolyzer assembled with NSQDs@NiFe-TPA and Ni_(3)S_(2)@NiFe-TPA as anodic and cathodic electrodes exhibited a low cell voltage of 1.66 V at a current density 10 mA cm^(-2),and almost no attenuation was observed after a 60 h stability test.The outstanding electrocatalytic properties of the as-prepared catalyst are due to the synergy of nickel sulfides and 2D MOFs that offers abundant accessible active sites,rapid ion/electron transportation,and convenient O_(2)/H_(2)release channels.
