A new type of acetylene gas sensor based on a hollow heterostructure

Abstract

A new type of acetylene gas sensor based on the hollow NiO/SnO₂ heterostructure synthesized by a two-step hydrothermal method followed by calcination was fabricated. The properties of the sensing material were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Brunauer–Emmett–Teller (BET) and transmission electron microscopy (TEM). The acetylene gas-sensing performances were investigated. Compared with the pure SnO₂ gas sensor, the response of the hollow NiO/SnO₂ heterostructure gas sensor to 100 ppm acetylene (C₂H₂) was raised to 13.8 from 5.4 at the optimum operating temperature of 206 °C. A wide detection range from 1 to 1000 ppm and a low minimum detection limit of 1 ppm were obtained. In addition, the hollow NiO/SnO₂ heterostructure gas sensor had a good repeatability, selectivity, stability and rapid response–recovery characteristics.