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%.