Cobalt−Iron Oxide Nanosheets for High‐Efficiency Solar‐Driven CO<sub>2</sub>−H<sub>2</sub>O Coupling Electrocatalytic Reactions
Yuying Mi, Yuan Qiu, Yifan Liu, Xianyin Peng, Min Hu, Shunzheng Zhao, Huanqi Cao, Longchao Zhuo, Hongyi Li, Junqiang Ren, Xijun Liu, Jun Luo
Abstract
Abstract Solar‐driven electrochemical overall CO 2 splitting (OCO 2 S) offers a promising route to store sustainable energy; however, its extensive implementation is hindered by the sluggish kinetics of two key reactions (i.e., CO 2 reduction reaction and oxygen evolution reaction (CO 2 RR and OER, respectively)). Here, as dual‐functional catalysts, Co 2 FeO 4 nanosheet arrays having high electrocatalytic activities toward CO 2 RR and OER are developed. When the catalyst is applied to a complete OCO 2 S system driven by a triple junction GaInP 2 /GaAs/Ge photovoltaic cell, it shows a high photocurrent density of ≈13.1 mA cm −2 , corresponding to a remarkably high solar‐to‐CO efficiency of 15.5%. Density functional theory studies suggest that the Co sites in Co 2 FeO 4 are favorable to the formation of *COOH and *O intermediates and thus account for its efficient bifunctional activities. The results will facilitate future studies for designing highly effective electrocatalysts and devices for OCO 2 S.