Preparation Of CuO/SnO₂ Film By Electrodeposition And Oxidation And Its Response To CO And H₂S

SnO2 is a kind of resistance sensor with good stability and interoperability, but has long response time. Doping CuO can improve SnO2 surfacial properti and increase its reponse.CuO/SnO2 thin film was obtained by oxygizing Cu-Sn film electrodeposited on ITO glass from solution of SnCl2, CuCl2 and natrium citrate at high temperature. The CuO/SnO2 film was characterized by SEM and XRD. The influences of voltage, time, oxidation temperature and time on the thin film was investigated. The crystal of prepared CuO/SnO2 is homogeneous and porous with crystal size about hundreds of nanometer and is suitable to be used as gas sensors. The optimized conditions for preparation CuO/SnO2 thin film are followings:SnCl2 concentration 7.0g/L, voltage and time of electrodeposition Sn are-0.9V, 3600s; CuCl2 concentration 2.0g/L, voltage and time of electrodeposition Cu are-1.2V,600s; Oxidation temperature and time are 600℃,10 h.The responses of CuO/SnO2 to CO and H2S in air were measured by resistance method and the response mechanism was discussed. The results show that CuO/SnO2 film has high response to H2S and CO at low and high temperature respectively.