Wet-chemistry fabrication of BaTiO3@TiOx for enhanced tribocatalytic degradation of water pollutant

Abstract

Tribocatalysis is an emerging methodology for water purification by harnessing frictional energy. BaTiO3 has shown promising activity in the tribocatalytic degradation of organic pollutants; however, further performance improvement through structural and surface engineering remain challenge. Herein, a facile wet chemistry method was employed to modify the surface of commercial BaTiO3 by depositing TiOx colloids, which enhanced the reaction rate from 0.080 h-1 for pristine BaTiO3 to 0.272 h-1 for BaTiO3 modify by TiOx colloids. The catalysts were characterized by XRD, TEM, XPS, and Raman and the results indicated that the modified BaTiO3 consisted of a BaTiO3 core encapsulated by an ultrathin TiOx shell with an increased concentration of oxygen vacancies. UV-vis, PL spectra, EIS, and DFT calculations demonstrated that the TiOx modification effectively narrows the band gap energy and promotes the separation of electron-hole pairs during tribocatalysis, thereby facilitating the production of more reactive species. Combining EPR analysis and quenching tests, tribogenerated holes were identified as the predominant reactive species surpassing the contributions of •O2- and •OH. This study highlights the efficacy of the wet chemistry approach for the rational design of advanced tribocatalysts, offering new insights into optimizing catalytic materials for the degradation of organic contaminants.