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

Abstract

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 SnO₂–SnO₂ 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.