Improvement of copper oxide–tin oxide sensor for dilute hydrogen sulfide

Abstract

The influence of the loading and dispersion of CuO on the H₂S-sensing properties of CuO–SnO₂ sensors has been investigated. The response rates to H₂S depend on various factors such as CuO loading, specific surface area (or size) of SnO₂ grains, method of loading the SnO₂ grains with CuO and the operating temperature. For the CuO–SnO₂ sensor prepared by a chemical fixation method, the response rates to dilute H₂S (1–10 ppm) increased with decreasing CuO loading, while the sensitivity to H₂S decreased monotonically with decreasing amount of CuO dispersed per unit surface area of SnO₂. By optimizing these factors, it was possible to obtain a CuO–SnO₂ sensor which responded to H₂S above 1 ppm at 160 °C with sufficient sensitivity and fairly good response kinetics.