Photoassisted Electrochemical Hydrogen Evolution Reaction of MFe<sub>2</sub>O<sub>4</sub>@Ultrathin Black Phosphorus Amorphous–Crystalline Interface
Chang‐Chun Fan, Zhenzhen Wan, Meiling Pan, Juan Hou, Yulin Shi, Wen Guo, Gang Wang, Shanglong Peng, Qun Jing, Long Chen
Abstract
Exploring highly active, stable, and low-cost catalysts for photoelectrochemical hydrogen evolution reaction (PE-HER) is vital in the field of energy conversion. Herein, we construct a new amorphous crystalline interface that amorphous iron-based spinel oxide (A-MFe2O4 (M = Ni, Co, Zn)) is uniformly anchored on the crystalline exfoliated black phosphorus (C-EBP) nanosheets via electrochemical and solvothermal strategies. Among these A-MFe2O4@C-EBP catalysts, more oxygen defects of A-NiFe2O4@C-EBP interface provide a larger effective electrochemical active area of 32.33 mF cm–2 as well as a turnover frequency of 0.44 s–1 and allow for an optimum equilibrium of the hydrogen-containing adsorption intermediates. Furthermore, A-NiFe2O4@C-EBP exhibits significant PE-HER performance with an overpotential of 42 mV at 10 mA cm–2 under visible-light irradiation. Density functional theory (DFT) calculations show that the amorphous–crystalline composite structure causes a large number of oxygen defects enhancing the intrinsic activity of A-NiFe2O4@C-EBP, which A-NiFe2O4@C-EBP significantly improves its adsorption capacity for H* for HER and has the lowest Gibbs free energy change for HER. This study not only provides a superior multifunctional amorphous–crystalline interface catalysts but also helps to understand the catalytic mechanism of PE-HER.