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

Efficient photocatalytic reduction of CO2 to high-calorific-value CH4, an ideal target product, is a blueprint for C-1 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 mu mol 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 pi-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.