Highly selective photocatalytic reduction of CO2 to CH4 on electron‐rich Fe species cocatalyst under visible light irradiation

Abstract

Abstract Efficient photocatalytic reduction of CO2 to high‐calorific‐value CH4, an ideal target product, is a blueprint for C1 industry relevance and carbon neutrality, but it also faces great challenges. Herein, we demonstrate unprecedented hybrid SiC photocatalysts modified by Fe‐based cocatalyst, which are prepared via a facile impregnation‐reduction method, featuring an optimized local electronic structure. It exhibits a superior photocatalytic carbon‐based products yield of 30.0 µmol g−1 h−1 and achieves a record CH4 selectivity of up to 94.3%, which highlights the effectiveness of electron‐rich Fe cocatalyst for boosting photocatalytic performance and selectivity. Specifically, the synergistic effects of directional migration of photogenerated electrons and strong π‐back bonding on low‐valence Fe effectively strengthen the adsorption and activation of reactants and intermediates in the CO2 → CH4 pathway. This study inspires an effective strategy for enhancing the multielectron reduction capacity of semiconductor photocatalysts with low‐cost Fe instead of noble metals as cocatalysts.

Keywords

• artificial synthesis of CH4
• electronic structure optimization
• Fe species cocatalyst
• photocatalytic CO2 reduction
• SiC