Efficient Conversion of CO₂ to Methane Photocatalyzed by Conductive Black Titania

Abstract

One of the major challenges encountered in CO₂ utilization is the development of available and cost‐efficient catalysts with sufficient activity, selectivity, and stability for the generation of useful methane. Here, conductive black titania, TiO_2−x , is found to be efficient in photocatalyzing the reduction of CO₂ to CH₄. This unique material comprises a crystalline core–amorphous shell structure (TiO₂@TiO_2−x ) with numerous surface oxygen vacancies, which facilitates the adsorption and chemical activation of CO₂ molecules. Under full solar irradiation, the optimized 500‐TiO_2−x material with narrowed band gap and intermediate states below the conduction band tail exhibits a high space‐time yield of CH₄ of 14.3 μmol g⁻¹ h⁻¹, with 74 % selectivity and excellent photostability. The present findings can make a significant contribution, not only to develop the surface electron‐modified black TiO₂ catalyst to boost photocatalytic efficiency, but also to establish a really viable and convenient CH₄ production process for CO₂ conversion and renewable solar energy storage.