CuO/CeO2 Nanocomposites With p–n Heterojunction for Photocatalytic CO2 Reduction to CH4

Abstract

CH4 is a significant fuel with considerable industrial value. Photocatalytic CO2 reduction presents an effective strategy for producing CH4, offering a green, environmentally friendly, and sustainable solution. However, challenges such as inefficient light absorption and inadequate separation and transport of photogenerated electron-hole pairs are crucial barriers to its progress. Herein, an efficient CuO/CeO2 photocatalyst with p-n heterojunction was prepared for the photocatalytic reduction of CO2 to CH4. CuO/CeO2 exhibited improved light absorption efficiency, along with enhanced separation and transport of photogenerated charges, leading to superior photocatalytic performance compared with individual CuO and CeO2. Only CO was detected on CuO or CeO2. In contrast, CuO/CeO2 produced CH4 and C2H4 at yields of 80.2 µmol·g−1 and 2.1 µmol·g−1 within 4 h, respectively. And the selectivity for CH4 reached up to 97.4%.