Efficient Conversion of CO 2 to Methane Photocatalyzed by Conductive Black Titania

One of the major challenges encountered in CO 2 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 CO 2 to CH 4 . This unique material comprises a crystalline core–amorphous shell structure (TiO 2 @TiO 2− x ) with numerous surface oxygen vacancies, which facilitates the adsorption and chemical activation of CO 2 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 CH 4 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 TiO 2 catalyst to boost photocatalytic efficiency, but also to establish a really viable and convenient CH 4 production process for CO 2 conversion and renewable solar energy storage.