Self-supported CsPbBr₃/Ti₃C₂T_x MXene aerogels towards efficient photocatalytic CO₂ reduction

Aerogels, especially MXene aerogels, are an ideal multifunctional platform for developing efficient photocatalysts for CO₂ reduction because they are featured by abundant catalytic sites, high electrical conductivity, high gas absorption ability and self-supported structure. However, the pristine MXene aerogel has almost no ability to utilize light, which requires additional photosensitizers to assist it in achieving efficient light harvesting. Herein, we immobilized colloidal CsPbBr₃ nanocrystals (NCs) onto the self-supported Ti₃C₂T_x (where T_x represents surface terminations such as fluorine, oxygen, and hydroxyl groups) MXene aerogels for photocatalytic CO₂ reduction. The resultant CsPbBr₃/Ti₃C₂T_x MXene aerogels exhibit a remarkable photocatalytic activity toward CO₂ reduction with total electron consumption rate of 112.6 μmol g^-1h^-1, which is 6.6-fold higher than that of the pristine CsPbBr₃ NC powders. The improvement of the photocatalytic performance is presumably attributed to the strong light absorption, effective charge separation and CO₂ adsorption in the CsPbBr₃/Ti₃C₂T_x MXene aerogels. This work presents an effective perovskite-based photocatalyst in aerogel form and opens a new avenue for their solar-to-fuel conversions.