In Situ Construction of SnS<sub>2</sub>@SnO<sub>2</sub> Heterostructure for Photo‐Assisted Electrocatalysis of Oxygen Evolution Reaction
Jinnong Wang, Ze Wang, Jie He, Lin Han, Xin Li, Keyi Han, Tianen Chen, Qianyu Zhou, Luobai Yang, Dongye Zhao, Yuanhao Wang, Shifeng Wang
Abstract
Abstract Photo‐assisted electrocatalysis has arisen as a promising approach for hydrogen generation by incorporating photocatalysts into electrocatalysts. 2D SnS 2 is a photocatalyst that absorbs visible light. However, the rapid recombination of photo‐generated electron‐hole pairs significantly reduces the overall photocatalytic efficiency of SnS 2 , limiting its practical application. Thus, this study prepares an in situ heterojunction SnS 2 @SnO 2 using a one‐step hydrothermal method. The degradation efficiency of methyl orange (MO) using SnS 2 @SnO 2 is measured, achieving a degradation rate of 92.75% within 1 h, which is 1.9 times higher than that of pure SnS 2 . Additionally, FeNiS/SnS 2 @SnO 2 is synthesized and exhibited significant improvements in the photo‐assisted oxygen evolution reaction (OER). It achieves an overpotential of 260 mV and a Tafel slope of 65.1 mV dec −1 at 10 mA cm −2 , showing reductions of 11.8% and 31.8%, respectively, compared to FeNiS alone. These enhancements highlight the strong photo‐response capability of SnS 2 @SnO 2 . Under the internal electric field of SnS 2 @SnO 2 , the photogenerated electrons in the conduction band of SnS 2 quickly move toward SnO 2 , facilitating efficient photocatalytic reactions. FeNiS, with a lower Fermi energy level (E F ), facilitates electron transfer from SnS 2 @SnO 2 and enhances OER performance by efficiently participating in the reaction. This study paves a new path for 2D photocatalyst materials.