Light‐Driven Low‐Temperature and Near‐Unity Conversion of Ester on a Perovskite Derivative Photothermal Catalyst via Photon‐Bismuth Triggered Hotspot

Abstract Solar‐driven photothermal chemical transformations are regarded as green processes to reduce energy consumption and are expected to utilize unique light‐induced activation mechanisms to improve reaction kinetics. Halide perovskites and their derivatives, due to unique optoelectronic properties and compositional flexibility, are allowed for the precise regulation of energy band structures and surface electronic states, showing potentials as photoactivated catalysts with photo‐thermal synergistic effects. However, the photothermal catalytic performance of halide perovskites is still unsatisfied with low conversion (<0.2%). Herein, Cs ₃ Bi _x Sb _{2‐ x} Br ₉ is designed as a novel and effective photothermal catalyst for light‐driven degradation of ester under room temperature, achieving a near‐unity conversion of ≈99% without external heating. Photothermal catalytic process shows the remarkable enhancementup to 796% and 200% compared with that in the single thermocatalysis or photocatalysis. The stable catalyst shows superior light‐driven cyclic performance, as well. Mechanistic studies combined with in situ characterizations and theoretical calculations show that photon‐bismuth hotspot with the synergy of photoinduced charge transfer process (photochemistry) significantly reduce the activation energy, light‐to‐heat effects (thermochemistry) elevate the local temperature, and bismuth active site promotes the C─O bond activation (surface adsorption), which together contribute to excellent solar‐driven conversion efficiency on the perovskite derivative.