Ppb H_2S gas sensing characteristics of Cu_2O/CUO sub-microspheres at low-temperature

摘要

Cu_2O/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 ℃. It is found that the reaction temperature plays a very important role in the size, the Cu_2O content, and morphology of the products. The sub-microspheres obtained at the reaction temperature below 140 ℃ are assembled by smaller particles with a diameter of about 10 nm. As the reaction temperature is increased to above 160 ℃, uneven samples with larger size will be synthesized. The sensing performances of the sub-microspheres are related to the Cu_2O content, porous characteristics and their surface areas. The sensor response of the sub-microspheres obtained at 120 ℃ is up to 2.1-50 ppb H_2S gas at 95 ℃, and the recovery time is only about 76 s. Thus, the sub-microspheres are promising for H_2S sensors.