Effect of SnO Composition in SnO/SnO ₂ Nanocomposites on the Photocatalytic Degradation of Malachite Green under Visible Light

Abstract

Abstract Three types of SnO/SnO 2 nanocomposites with different component ratios were synthesized using a simple hydrothermal process. Three samples, S1, S2, and S3, were produced by optimizing the occupied volume inside the Teflon flask, and are referred to as SnO 2 rich, intermediate level, and SnO rich, respectively. In terms of degradation of malachite green under visible light, the photocatalytic activity of the S2 sample outperforms the other two samples and pure SnO by 30 %. It is attributed to the fact that the S2 sample has the most heterojunction between p‐type SnO and n‐type SnO 2 of the three samples because the formation of p‐type SnO and n‐type SnO 2 heterojunction in S2 prevents photogenerated electron‐hole recombination. By comparing S1 and S3 samples, we figured out that Sn 2+ doped into the SnO 2 lattice acts as an electron trap, slowing the recombination process and increasing photocatalytic activity.