Tribocatalytic activity on Ba(Ti0.95Zr0.05)O3 surfaces: The role of oxygen vacancies and the aging effect

This study explores the potential of tribocatalysis, a resource-efficient degradation technique, using ferroelectric perovskite-type Ba(Ti0.95Zr0.05)O3 (BZT) with oxygen vacancies as a catalyst. The catalysts, synthesized via a standard solid-state method, were analyzed using XPS and EPR to confirm the presence of oxygen vacancies. Their electrical properties were evaluated through UV–vis diffuse reflectance spectra and Mott–Schottky plots. Freshly prepared BZT catalysts demonstrated a 92% degradation of Rhodamine B (RhB) within 20 h, achieving a reaction rate constant (K) of 0.114 h−1. However, aging significantly reduced RhB degradation, with de-aging failing to restore initial activity. The study attributes the catalyst's catalytic activity and aging issues to the oxygen vacancies, acting as shallow donor states. It also highlights the benefits of tribocatalysis due to electron accumulation at the surface from friction-generated contact, emphasizing the critical role of oxygen vacancies in catalytic degradation and long-term catalyst stability.