Enhanced photocatalytic activity of single-atom Au1/TiO2 catalysts prepared using cold plasma

Abstract

Single-atom catalysts (SACs) have attracted significant attention due to their unique electronic structure and extraordinary catalytic reaction activity. In this work, single-atom Au₁/TiO₂ catalysts 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.