Highly Sensitive and Selective Sensing of H(2)S Gas Using Precipitation and Impregnation-Made CuO/SnO(2) Thick Films

In this work, CuO-loaded tetragonal SnO(2) nanoparticles (CuO/SnO(2) NPs) were synthesized using precipitation/impregnation methods with varying Cu contents of 0–25 wt% and characterized for H(2)S detection. The material phase, morphology, chemical composition, and specific surface area of NPs were evaluated using X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller analysis. From gas-sensing data, the H(2)S responses of SnO(2) NPs were greatly enhanced by CuO loading particularly at the optimal Cu content of 20 wt%. The 20 wt% CuO/SnO(2) sensor showed an excellent response of 1.36 × 10(5) toward 10 ppm H(2)S and high H(2)S selectivity against H(2), SO(2), CH(4), and C(2)H(2) at a low optimum working temperature of 200 °C. In addition, the sensor provided fast response and a low detection limit of less than 0.15 ppm. The CuO–SnO(2) sensor could therefore be a potential candidate for H(2)S detection in environmental applications.