Transition metal phosphides(TMPs)have emerged as an alternative to precious metals as efficient and low-cost catalysts for water electrolysis.Elemental doping and morphology control are effective approaches to further...Transition metal phosphides(TMPs)have emerged as an alternative to precious metals as efficient and low-cost catalysts for water electrolysis.Elemental doping and morphology control are effective approaches to further improve the performance of TMPs.Herein,Fe-doped CoP nanoframes(Fe-CoP NFs)with specific open cage configuration were designed and synthesized.The unique nano-framework structured Fe-CoP material shows overpotentials of only 255 and 122 mV at 10 mA cm^(−2)for oxygen evolution reaction(OER)and hydrogen evolution reaction(HER),respectively,overwhelming most transition metal phosphides.For overall water splitting,the cell voltage is 1.65 V for Fe-CoP NFs at a current density of 10 mA cm^(−2),much superior to what is observed for the classical nanocubic structures.Fe-CoP NFs show no activity degradation up to 100 h which contrasts sharply with the rapidly decaying performance of noble metal catalyst reference.The superior electrocatalytic performance of Fe-CoP NFs due to abundant accessible active sites,reduced kinetic energy barrier,and preferable*O-containing intermediate adsorption is demonstrated through experimental observations and theoretical calculations.Our findings could provide a potential method for the preparation of multifunctional material with hollow structures and offer more hopeful prospects for obtaining efficient earth-abundant catalysts for water splitting.展开更多
Achieving dual regulation of the kinetics and thermodynamics of MgH_(2) is essential for the practical applications.In this study,a novel nanocomposite(In@Ti-MX)architected from single-/few-layered Ti_(3)C_(2) MXenes ...Achieving dual regulation of the kinetics and thermodynamics of MgH_(2) is essential for the practical applications.In this study,a novel nanocomposite(In@Ti-MX)architected from single-/few-layered Ti_(3)C_(2) MXenes and ultradispersed indium nanoparticles was prepared by a bottom-up self-assembly strategy and introduced into MgH_(2) to solve the above-mentioned problems.The MgH_(2)+In@Ti-MX composites demonstrate excellent hydrogen storage performance:The resultant In@Ti-MX demonstrated a positive effect on the hydrogen storage performance of MgH_(2)/Mg:the dehydrogenated rate of MgH_(2)+15 wt%In@Ti-MX reached the maximum at 330°C,which was 47°C lower than that of commercial MgH_(2);The hydrogenation enthalpy of the dehydrided MgH_(2)+15 wt%In@Ti-MX and MgH_(2)+25 wt%In@Ti-MX were determined to be−66.2±1.1 and−61.7±1.4 kJ·mol^(−1) H_(2).In situ high-energy synchrotron x-ray diffraction technique together with other microstructure analyses revealed that synergistic effects from Ti_(3)C_(2) MXenes and In nanoparticles(NPs)contributed to the improved kinetics and thermodynamics of MgH_(2)(Mg):Ti/TiH_(2) derived from Ti_(3)C_(2) MXenes accelerated the dissociation and recombination of hydrogen molecule/atoms,while In NPs reduced the thermodynamic stability of MgH_(2) by forming the Mg-In solution.Such a strategy of using dual-active hybrid structures to modify MgH_(2)/Mg provides a new insight for tuning both the hydrogen storage kinetics and thermodynamics of Mg-based hydrides.展开更多
基金the China Scholarship Council(CSC)for the financial support(202206230096)D.Yu would like to thank the CSC for the Doctor scholarship(202006360037)+1 种基金J.Dutta would like to acknowledge the partial financial support of VINNOVA project no.2021-02313.PZhang would like to acknowledge partial financial support from the National Natural Science Foundation of China(Nos 52111530187,51972210).
文摘Transition metal phosphides(TMPs)have emerged as an alternative to precious metals as efficient and low-cost catalysts for water electrolysis.Elemental doping and morphology control are effective approaches to further improve the performance of TMPs.Herein,Fe-doped CoP nanoframes(Fe-CoP NFs)with specific open cage configuration were designed and synthesized.The unique nano-framework structured Fe-CoP material shows overpotentials of only 255 and 122 mV at 10 mA cm^(−2)for oxygen evolution reaction(OER)and hydrogen evolution reaction(HER),respectively,overwhelming most transition metal phosphides.For overall water splitting,the cell voltage is 1.65 V for Fe-CoP NFs at a current density of 10 mA cm^(−2),much superior to what is observed for the classical nanocubic structures.Fe-CoP NFs show no activity degradation up to 100 h which contrasts sharply with the rapidly decaying performance of noble metal catalyst reference.The superior electrocatalytic performance of Fe-CoP NFs due to abundant accessible active sites,reduced kinetic energy barrier,and preferable*O-containing intermediate adsorption is demonstrated through experimental observations and theoretical calculations.Our findings could provide a potential method for the preparation of multifunctional material with hollow structures and offer more hopeful prospects for obtaining efficient earth-abundant catalysts for water splitting.
基金National Natural Science Foundation(No.52171186)The authors also appreciate the financial support from China Minmetals Corporation and the Center of Hydrogen Science,Shanghai Jiao Tong University,China.
文摘Achieving dual regulation of the kinetics and thermodynamics of MgH_(2) is essential for the practical applications.In this study,a novel nanocomposite(In@Ti-MX)architected from single-/few-layered Ti_(3)C_(2) MXenes and ultradispersed indium nanoparticles was prepared by a bottom-up self-assembly strategy and introduced into MgH_(2) to solve the above-mentioned problems.The MgH_(2)+In@Ti-MX composites demonstrate excellent hydrogen storage performance:The resultant In@Ti-MX demonstrated a positive effect on the hydrogen storage performance of MgH_(2)/Mg:the dehydrogenated rate of MgH_(2)+15 wt%In@Ti-MX reached the maximum at 330°C,which was 47°C lower than that of commercial MgH_(2);The hydrogenation enthalpy of the dehydrided MgH_(2)+15 wt%In@Ti-MX and MgH_(2)+25 wt%In@Ti-MX were determined to be−66.2±1.1 and−61.7±1.4 kJ·mol^(−1) H_(2).In situ high-energy synchrotron x-ray diffraction technique together with other microstructure analyses revealed that synergistic effects from Ti_(3)C_(2) MXenes and In nanoparticles(NPs)contributed to the improved kinetics and thermodynamics of MgH_(2)(Mg):Ti/TiH_(2) derived from Ti_(3)C_(2) MXenes accelerated the dissociation and recombination of hydrogen molecule/atoms,while In NPs reduced the thermodynamic stability of MgH_(2) by forming the Mg-In solution.Such a strategy of using dual-active hybrid structures to modify MgH_(2)/Mg provides a new insight for tuning both the hydrogen storage kinetics and thermodynamics of Mg-based hydrides.
