Boosting the piezo-photocatalytic performance of Na0.5Bi0.5TiO3 by modulating the oxygen vacancy concentration

The emergence of piezo-photocatalysis inaugurates a nascent approach aimed at mitigating the rapid recombination of electrons and holes, thus augmenting catalytic efficacy. This work endeavors to fabricate Na0.5Bi0.5TiO3 (BNT) nanosphere powders through a simplified hydrothermal method, whereby precise control over the quantity of tetrabutyl titanate, a titanium source, is employed. The piezo-photocatalytic performance of BNT nanospheres is meticulously scrutinized through the degradation of Rhodamine B (RhB) at a concentration of 5 mg/L, utilizing ultrasonic vibration and UV-visible light irradiation. Remarkably, the appropriate balance between oxygen and titanium vacancies exerts a profound impact on the efficiency of piezoelectric photocatalytic degradation. Among the investigated catalysts, The material with the best performance exhibits the highest rate of piezo-photocatalytic degradation, boasting a rate constant (k value) of 0.052 min-1. Furthermore, the BNT nanospheres exhibit commendable stability and reusability in the context of piezo-photocatalytic degradation. Elucidation of the piezo-photocatalytic mechanism of BNT nanospheres is attained through the identification of radicals and intermediates present in the degradation process. This research imparts invaluable guidance for the design and development of state-of-the-art and high-performance piezo-photocatalytic catalysts.