Isostructural phase transition-induced piezoelectricity in all-inorganic perovskite CsPbBr3 for catalytic CO2 reduction

One charming characteristic of all-inorganic halide perovskites is their phase transition behavior which always generates an asymmetry-induced piezoelectric property under external stimuli. Here, under vibration pressure, an isostructural phase transition (IPT)-induced piezoelectricity occurs in a nanocube-like CsPbBr3 (CPB NC) to achieve catalytic reduction of CO2. Yields of reduction products reach to 7 mu mol g(-1) h(-1) (CH4) and 16 mu mol g(-1) h(-1) (CO), respectively, which are higher yet more stable than that of conventional photocatalytic CO2 reduction by CPB NC and other state-of-the-art halide perovskites. Theoretical calculations and exhaustive characterizations including in-situ high-pressure tests and atomic force microscopy confirm CPB NC carries out the IPT process to form polarized electric-field with high-piezoelectric potential which drives band tilting to excite piezoelectric carriers in CO2 reduction. This study reveals phase transition engineering with piezoelectric effect and marks a new step towards CO2 conversion with halide perovskites.