Oxygen vacancies-rich BaTiO3 for boosting tribocatalytic degradation of water pollutant by harvesting friction energy

Tribocatalysis for environmental remediation faces ongoing challenges related to elucidating complex mechanistic pathways and achieving efficient performance. Engineering surface oxygen vacancies within material systems holds promise for improving overall tribocatalytic efficiency. Herein, a facile solid-phase reduction method was used to generate oxygen vacancies-rich BaTiO 3 (R-BaTiO 3 ). Both the pristine BaTiO 3 and R-BaTiO 3 can harvest friction energy for further tribocatalytic degradation of RhB. The R-BaTiO 3 exhibited remarkably higher degradation rate constant for RhB removal, i.e., 0.177 h −1 , than that for the pristine BaTiO 3 , i.e., 0.0789 h −1 . The introduction of oxygen vacancies in R-BaTiO 3 reduced the energy bandgap and facilitated effective electron-hole separation, leading to the generation of more reactive oxygen species (•O 2 − and •OH). Tribo-generated holes were identified as the primary reactive species responsible for RhB degradation, surpassing the contributions of •O 2 − and •OH. A preliminary reaction mechanism based on both electron transfer and electron citation was proposed. The solid-phase reduction method employed in this study presents a promising way for enhancing tribocatalytic performance by introducing oxygen vacancies.