Enhanced sensitivity and selectivity of brush-like SnO2 nanowire/ZnO nanorod heterostructure based sensors for volatile organic compounds

Brush-like SnO2 nanowires have been grown by pulsed laser deposition on ZnO nanorods synthesized by the hydrothermal method. SnO2 nanowire/ZnO nanorod heterostructures have been used for sensing several volatile organic compounds (VOCs). The heterostructure sensor exhibits higher response compared to that of control ZnO nanorods. The potential barriers formed at the SnO2-ZnO and SnO2SnO2 interface are proposed to be responsible for an improved sensing performance over the pure ZnO nanorods. The effect of the length of SnO2 nanowires on the performance of triethylamine, toluene, ethanol, acetic acid, acetone, and methanol sensing has been studied. It is found that the response to the VOCs greatly depends on the length of the brush-like SnO2 nanowires. The SnO2/ZnO heterostructures can be successfully used to discriminate acetone from other VOCs.