Photocatalytic removal of NO and HCHO over nanocrystalline Zn 2SnO 4 microcubes for indoor air purification

Abstract

Nanocrystalline Zn 2SnO 4 microcubes were hydrothermally synthesized and systematically characterized by XRD, SEM, TEM, XPS, N 2 adsorption–desorption, and UV–vis DRS analysis. The resulting Zn 2SnO 4 microcubes with the edge size ranging from 0.8 to 1.2 μm were composed of numerous nanoparticles with size of 10–20 nm, and their optical band gap energy was estimated to be 3.25 eV from the UV–vis diffuse reflectance spectra. On degradation of nitrogen monoxide (NO) and formaldehyde (HCHO) at typical concentrations for indoor air quality, these nanocrystalline Zn 2SnO 4 microcubes exhibited superior photocatalytic activity to the hydrothermally synthesized ZnO, SnO 2, and Degussa TiO 2 P25, as well as C doped TiO 2 under UV–vis light irradiation. This enhanced photocatalytic activity of the nanocrystalline Zn 2SnO 4 microcubes was attributed to their bigger surface areas, smaller particle size, special porous structures, and special electronic configuration. The nanocrystalline Zn 2SnO 4 microcubes were chemically stable as there was no obvious deactivation during the multiple photocatalytic reactions. This work presents a promising approach for scaling-up industrial production of Zn 2SnO 4 nanostructures and suggests that the synthesized nanocrystalline Zn 2SnO 4 microcubes are promising photocatalysts for indoor air purification.