Dynamic Strain Engineering Boosts Piezo-Photocatalytic CO ₂ Reduction on BaTiO ₃ Nanobats

Barium titanate (BaTiO 3 ) exhibits high chemical stability; however, the relatively rapid recombination of charge carriers severely limits its photocatalytic performance. Meanwhile, electrocatalysis facilitates charge transport by generating a spontaneously polarized electric field, effectively suppressing charge carrier recombination, but the performance of conventional ferroelectric catalysts is inherently constrained by their low surface piezopotential. In this study, a piezo-photocatalytic system triggered by ultrasonic vibration is reported, based on BaTiO 3 nanobats. The BaTiO 3 structure resembles a nanobat, featuring a thicker lower cylindrical body (∼35 nm diameter) and a thinner upper section (∼20 nm diameter) with a total length of about 250 nm. It can generate a piezo-potential as high as 1.2 V through COMSOL finite element simulation. Under mild vibration, the BaTiO 3 nanobats exhibit superior piezo-photocatalytic performance, converting CO 2 into CO with a maximum yield of 101.18 μmol·g –1 ·h –1 . The yield is approximately five times higher than that achieved with ultraviolet light irradiation alone. Furthermore, theoretical calculations reveal that the adsorption and desorption of intermediates (*COOH, *CO) on BaTiO 3 can be regulated by applying different strains. The piezo-photocatalytic CO 2 reduction reaction opens an avenue beyond conventional photocatalysis, expanding energy utilization to pave the way for carbon neutrality.