Phosphorus-doped Fe7S8@C nanowires for efficient electrochemical hydrogen and oxygen evolutions: Controlled synthesis and electronic modulation on active sites
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2021年第15期
论文作者：Thanh-Tung Le Xiao Liu Peijun Xin Qing Wang Chunyan Gao Ye Wu Yong Jiang Zhangjun Hu Shoushuang Huang Zhiwen Chen
摘 要：Developing low-cost, efficient, and stable non-precious-metal electrocatalysts with controlled crystal structure, morphology and compositions are highly desirable for hydrogen and oxygen evolution reactions. Herein, a series of phosphorus-doped Fe7S8 nanowires integrated within carbon（P-Fe7S8@C）are rationally synthesized via a one-step phosphorization of one-dimensional（1D） Fe-based organicinorganic nanowires. The as-obtained P-Fe7S8@C catalysts with modified electronic configurations present typical porous structure, providing plentiful active sites for rapid reaction kinetics. Density functional calculations demonstrate that the doping Fe7S8 with P can effectively enhance the electron density of Fe7S8 around the Fermi level and weaken the Fe-H bonding, leading to the decrease of adsorption free energy barrier on active sites. As a result, the optimal catalyst of P-Fe7S8-600@C exhibits a relatively low overpotential of 136 m V for hydrogen evolution reaction（HER） to reach the current density of 10 m A/cm2, and a significantly low overpotential of 210 m V for oxygen evolution reaction（OER） at 20 m A/cm2 in alkaline media. The work presented here may pave the way to design and synthesis of other prominent Fe-based catalysts for water splitting via electronic regulation.
Thanh-Tung Le1，Xiao Liu1，Peijun Xin1，Qing Wang1，Chunyan Gao1，Ye Wu1，Yong Jiang1，Zhangjun Hu1,2，Shoushuang Huang1，Zhiwen Chen1
1. School of Environmental and Chemical Engineering, Shanghai University2. Department of Physics, Chemistry and Biology, Link?ping University
摘 要：Developing low-cost, efficient, and stable non-precious-metal electrocatalysts with controlled crystal structure, morphology and compositions are highly desirable for hydrogen and oxygen evolution reactions. Herein, a series of phosphorus-doped Fe7S8 nanowires integrated within carbon（P-Fe7S8@C）are rationally synthesized via a one-step phosphorization of one-dimensional（1D） Fe-based organicinorganic nanowires. The as-obtained P-Fe7S8@C catalysts with modified electronic configurations present typical porous structure, providing plentiful active sites for rapid reaction kinetics. Density functional calculations demonstrate that the doping Fe7S8 with P can effectively enhance the electron density of Fe7S8 around the Fermi level and weaken the Fe-H bonding, leading to the decrease of adsorption free energy barrier on active sites. As a result, the optimal catalyst of P-Fe7S8-600@C exhibits a relatively low overpotential of 136 m V for hydrogen evolution reaction（HER） to reach the current density of 10 m A/cm2, and a significantly low overpotential of 210 m V for oxygen evolution reaction（OER） at 20 m A/cm2 in alkaline media. The work presented here may pave the way to design and synthesis of other prominent Fe-based catalysts for water splitting via electronic regulation.
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