Ppb H2S gas sensing characteristics of Cu2O/CuO sub-microspheres at low-temperature

Cu2O/CuO sub-microspheres were synthesized via a one-step reduction approach using copper (II) acetate as precursor in triethylene glycol solution at reaction temperature ranging from 100 to 180 degrees C. It is found that the reaction temperature plays a very important role in the size, the Cu2O content, and morphology of the products. The sub-microspheres obtained at the reaction temperature below 140 degrees C are assembled by smaller particles with a diameter of about 10 nm. As the reaction temperature is increased to above 160 degrees C, uneven samples with larger size will be synthesized. The sensing performances of the sub-microspheres are related to the Cu2O content, porous characteristics and their surface areas. The sensor response of the sub-microspheres obtained at 120 degrees C is up to 2.1-50 ppb H2S gas at 95 degrees C, and the recovery time is only about 76 s. Thus, the sub-microspheres are promising for H2S sensors. (C) 2013 Elsevier B.V. All rights reserved.