Enhanced Photocatalytic Activity of Single-Atom Catalyst Au1/TiO2 Prepared via Cold Plasma

Single-atom catalysts (SACs) have attracted significant attention due to their unique electronic structure and extraordinary catalytic reaction activity. In this work, the single-atom catalysts Au1/TiO2 were successfully prepared using cold plasma. Notably, plasma-treated TiO2 introduces a substantial number of oxygen vacancies, which played a confinement effect on gold atoms. Au1/TiO2 achieved a remarkable 67% degradation of RhB in just 120 minutes, surpassing the performance of AuNPs/TiO2 by 2.8 times. The high catalytic activity can be attributed to several factors. Firstly, plasma-treated TiO2 contained a higher density of oxygen vacancies and exhibited a narrower band gap, which improved light absorption and facilitated the anchoring of monoatomic Au on the catalyst surface. Additionally, the single-atom Au species exhibited stronger interactions with TiO2, enhancing light absorption and charge transfer capability. Simultaneously, the presence of SACs on the catalyst surface increased the number of active sites, promoting efficient separation of electron-hole pairs and consequently enhancing the photocatalytic degradation activity. Cold plasma technology offers a simple and environmentally friendly platform for the fabrication of SACs, opening up exciting possibilities for catalytic applications.