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Modulating Interband Energy Separation of Boron‐Doped Fe 7 S 8 /FeS 2 Electrocatalysts to Boost Alkaline Hydrogen Evolution Reaction
Author(s) -
Wu Jing,
Zhang Qin,
Shen Ke,
Zhao Rong,
Zhong Wenda,
Yang Chenfan,
Xiang Hui,
Li Xuanke,
Yang Nianjun
Publication year - 2022
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.202107802
Subject(s) - overpotential , electrocatalyst , density functional theory , materials science , catalysis , hydrogen , doping , boron , electronic structure , inorganic chemistry , chemistry , electrochemistry , computational chemistry , electrode , biochemistry , optoelectronics , organic chemistry
Cost‐effective transition metal sulfides (TMSs) are potential electrocatalysts for alkaline hydrogen evolution reaction (HER). However, free energies of hydrogen intermediates adsorbed on the TMSs (e.g., iron sulfides) are too negative, hindering their hydrogenase‐like catalytic activity. With an aim to improve the inherently catalytic activity of the TMSs, design of boron‐doped Fe 7 S 8 /FeS 2 (B‐Fe 7 S 8 /FeS 2 ) electrocatalysts on the base of the density functional theory (DFT) calculation results is first conducted in this work. Boron atoms doped into the Fe 7 S 8 /FeS 2 electrocatalysts are found to optimize the electronic structures of d ‐electrons of Fe atoms and p ‐electrons of S atoms. The interband energy separation between the d ‐orbitals of Fe atoms and the p ‐orbitals of S atoms in the B‐Fe 7 S 8 /FeS 2 electrocatalysts is thus shorter than that of a Fe 7 S 8 or FeS 2 electrocatalyst. The optimal B‐Fe 7 S 8 /FeS 2 electrocatalyst induces a boosted charge transfer process and features a low energy barrier of water dissociation and a high desorption efficiency of adsorbed hydrogen intermediates. In alkaline media, this HER electrocatalyst exhibits the overpotential of 113 mV to harvest a current density of 10 mA cm −2 . The proposed heteroatom‐doping is a feasible approach to modulate electronic structures of TMS electrocatalysts and further achieve their accelerated HER kinetics.