One-pot hydrothermal synthesis of highly efficient SnOx/Zn2SnO4 composite photocatalyst for the degradation of methyl orange and gaseous benzene

Zn2SnO4 (ZTO) based composites have a promising application in photocatalysis. Developing a facile route to prepare high performance ZTO based photocatalyst is still required. A one-pot hydrothermal method was developed in this work to prepare SnOx/ZTO (SZTO-H) for the first time. Several characterization techniques were used to investigate its composition, structure, optical property, and morphology. The results indicated that SnOx component is SnO2 accompanied by a trace amount of Sn2O3. A type-II heterojunction is formed at the interface of SnOx and ZTO, which leads to a wide separation of photo-induced electrons (e−) and holes (h+). Thus, compared to pristine SnO2 and ZTO, a higher and more stable photocatalytic activity was observed on SZTO-H. Although similar SnO2/ZTO composites could be prepared by solid-state reaction routes (SSRs), their activities are substantially lower than SZTO-H as the surface areas were significantly reduced and some surface defects were introduced. The photocatalytic performance of SZTO-H is even superior to P25. Besides ZTO, we believe that the developed synthesis strategy is also applicable to the preparation of other ternary oxides based composites like SnOx/ZnGa2O4 and SnO2/Mg2SnO4.