Highly Sensitive and Selective Sensing of H2S Gas Using Precipitation and Impregnation-Made CuO/SnO2 Thick Films
Pimpan Leangtanom, Anurat Wisitsoraat, Kata Jaruwongrangsee, Narong Chanlek, Adisorn Tuantranont, Sukon Phanichphant, Viruntachar Kruefu
Abstract
Abstract 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.