Zn2SnO4 QDs decorated Bi2WO6 nanoplates for improved visible-light-driven photocatalytic removal of gaseous contaminants

Zn2SnO4 quantum dots (QDs) decorated Bi2WO6 nanocomposites were prepared via a two-step hydrothermal reaction progress. The Zn2SnO4 QDs were highly dispersed onto the surface of plate-shaped n-type Bi2WO6, which allows more photons to be harvested and effectively improve the separation and utilization efficiencies of photoinduced electrons and holes due to the formation of heterojunction. Among them, 3% Zn2SnO4 QDs/Bi2WO6 nanocomposite showed the highest photocatalytic performance (95.5% of acetone degradation), compared with other different amounts of Zn2SnO4 QDs, which are 5.86 and 1.99 times higher than those of pure Bi2WO6, respectively. Meanwhile, the hybridized sample was investigated by four successive photocatalytic degradation of acetone under visible light, displaying great photo-stability. Furthermore, through in-situ FTIR, acetaldehyde, acetic acid and formaldehyde were certified as intermedias during the photocatalytic degradation of acetone. Based on these results, the relationship between photocatalytic activity and the formation of Zn2SnO4 QDs/Bi2WO6 heterojunction is further discussed and the possible reaction mechanism is proposed. Such novel photocatalyst as visible light responsive catalyst provides a new choice for the efficient degradation of contaminants.