Preparation and gas-sensing performances of ZnO/CuO rough nanotubular arrays for low-working temperature H2S detection

Nanotubular arrays composed of ZnO and CuO were prepared by ultrasonic spray pyrolysis (USP) and chemical bath deposition (CBD), consisting of internal hexagonal ZnO and external monoclinic CuO shell. Inside-out Ostwald ripening is proposed to explain the formation mechanism of the ZnO/CuO nanotubular arrays. The sensors based on ZnO/CuO nanostructure were fabricated and investigated the H2S-sensing properties. The results indicated that the sensor fabricated by ZnO/CuO nanotubes showed enhanced gas sensing properties compared to sensors based on pure ZnO nanorods and ZnO/CuO nanorods. These tubelike architectures could facilitate the diffusion and adsorption of the gas molecules, which could provide plenty of active sites between H2S gases and adsorbed oxygen. Therefore, an enhanced gas response, the relatively lower working temperature and shorter response time process could be achieved using ZnO/CuO tube-like architecture. (C) 2017 Published by Elsevier B.V.