Hydrothermally synthesized CuO based volatile organic compound gas sensor

In the present work, single-phase CuO particles were synthesized by a hydrothermal method and characterized by SEM, TEM and XRD. The gas sensing properties of the CuO based sensor to some representative flammable VOC gases such as ethanol, isopropanol, acetone, benzene, para-xylene and decane were investigated. The sensor resistance increased when exposed to these flammable analytes, as well as when the concentration of oxygen in air decreased. That phenomenon is attributed to the surface accumulation conduction mechanism of the p-type metal oxide semiconductor, when negatively charged surface oxygen desorbs from the surface of CuO and releases electrons back to the CuO bulk. According to our research, the detection limit of the CuO based sensor to decane was better than 1 ppm, which indicated the potential applications of CuO based sensors in detecting low concentration decane.