Gas sensing behavior of Cu2O and CuO/Cu2O composite nanowires synthesized by template-assisted electrodeposition

Abstract

Metal oxide-based conductometric gas sensors are one of the promising candidates for highly sensitive, harsh environment resilient, low cost and nontoxic sensors for industrial applications. Here we present conductometric gas sensors based on Cu2O and CuO/Cu2O composite nanowires investigated towards few VOCs and CO gases. The Cu2O nanowires with an average length of 8 µm and diameter of 180 nm were synthesized through template-assisted electrodeposition of Cu2O into a polycarbonate membrane pores, from an aqueous solution. The CuO/Cu2O composite nanowires were obtained by annealing the synthesized Cu2O nanowires in an oxygen environment. The morphology, dimension, and crystallography of the synthesized nanowires are studied using scanning electron microscopy and X-ray diffraction measurements before and after annealing process. Our proposed sensor based on Cu2O nanowires showed a fast response in sensing ethanol gas at 250 °C response values of 178 and 15% towards 50 and 1 ppm of ethanol, respectively. CuO/Cu2O nanowires behaved selective and sensitive at 150 °C with a response value of 55% towards 500 ppm of CO.