Amorphous‐TiO2‐Encapsulated CsPbBr3 Nanocrystal Composite Photocatalyst with Enhanced Charge Separation and CO2 Fixation

Abstract Artificially photocatalytic reduction of CO 2 into valuable chemicals, responding to the call of carbon neutral economy, has aroused considerable interests so far. Among those photocatalysts screened, an emerging and promising alternative of inorganic CsPbBr 3 perovskite has recently been reported. Here, to attain preferable photocatalytic performance, an amorphous‐TiO 2 ‐encapsulated CsPbBr 3 nanocrystal (CsPbBr 3 NC/a‐TiO 2 ) hybrid is demonstrated through a solution processing strategy. After optimizing the a‐TiO 2 matrix amount by tuning the tetrabutyl titanate precursor volume, the CsPbBr 3 NC/a‐TiO 2 composite exhibits a marvelous 6.5‐fold improvement on the consumption of photoelectrons in photocatalytic CO 2 reduction reaction when compared with the individual CsPbBr 3 NC. Such significant enhancement is ascribed to the accelerated electron–hole separation and the multiplied CO 2 adsorption. Thus, as an available prototype, this work offers a rational encapsulation design for efficient halide perovskite photocatalyst.