Photo‐Responsive Co3O4/CoS2 Heterojunction as an Efficient Electrocatalyst for the Oxygen Evolution Reaction

• DOI: 10.1002/celc.202200746
• Publication Date: 2022-09-06T14:28:27Z
• Authors: Yidan Gao; Tingting Du; Shijie Jia; Tianxiao Chen; Yuxi Zhang; Fengchun Yang; Xin Zhang
• Keywords: 13. Climate action; 01 natural sciences; 7. Clean energy; 0104 chemical sciences

AbstractDeveloping high‐efficiency electrocatalysts for oxygen evolution reaction (OER) based on non‐precious transition metal materials alternative to noble metal has remained a great challenge in electrochemical water splitting. Meanwhile, the use of clean and sustainable solar energy is also crucial for renewable energy storage. Herein, a novel photo‐responsive electrocatalyst with proper energy band type, i. e., n type CoS2 semiconductor decorated on p‐type Co3O4 nanorod (Co3O4/CoS2), is prepared via a simple two‐step hydrothermal process. Consequently, the Co3O4/CoS2 shows small overpotential of 255 mV for OER to afford current density of 10 mA cm−2 after illumination, which is 40 mV lower than that without illumination. It also presents high electrochemically active surface areas and good stability. This significantly enhanced electrocatalytic OER performance is attributable to increased oxygen vacancies and highly active Co−S species that are electrooxidized to active site (Co3+) during OER. This work provides an effective perspective for the development of high efficiency OER catalysts based on non‐noble metals combined with solar energy as a renewable energy source.