Ohmic contact Metal/ZnO heterostructure for CO <sub>2</sub> photoreduction to CO
Chaogang Ban, Xiao Su, Yurong An, Yu Xia, Honglin Zhou, Jiuyan Li, Jessica Ye, Lijun Wu, Jiangping Ma, Junjie Ding, Yang Wang, Yajie Feng, Xiaoping Tao, Li‐Yong Gan, Jiyan Dai, Xiaoyuan Zhou
Abstract
Abstract Photocatalytic CO 2 reduction using solar energy offers a promising path to carbon neutrality, with ZnO as a favored semiconductor due to its abundance, favorable band alignment, and eco‐friendliness. However, challenges such as high carrier recombination, limited light absorption, and poor CO 2 adsorption limit its performance. To overcome these issues, an Ohmic contact heterostructure strategy is proposed. A theoretical screening of five noble metals (Ag, Pd, Ir, Au and Pt) for forming Ohmic contact metal–semiconductor heterostructures with ZnO was conducted, followed by experimental validation. Among these, the Au/ZnO heterostructure, with an appropriate Fermi level difference (Δ( Ф ZnO — Ф metal )) of 2.02 eV, achieved the highest CO yield of 28.66 μmol g –1 h −1 , significantly outperforming than other Metal/ZnO combinations. Further investigation of Au/ZnO revealed that the Ohmic contact enhances photogenerated carrier separation, while Au nanoparticles serve as active sites and promote key reactions, including CO 2 adsorption, *COOH formation, and *CO desorption, leading to improved CO 2 reduction efficiency. This work provides valuable insights into the design of high‐performance photocatalysts based on Ohmic contact heterostructures, offering potential solutions for energy and environmental challenges.