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

Barium titanate (BaTiO3) 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 BaTiO3 nanobats. The BaTiO3 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 BaTiO3 nanobats exhibit superior piezo-photocatalytic performance, converting CO2 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 BaTiO3 can be regulated by applying different strains. The piezo-photocatalytic CO2 reduction reaction opens an avenue beyond conventional photocatalysis, expanding energy utilization to pave the way for carbon neutrality.