In situ deposited hierarchical CuO/NiO nanowall arrays film sensor with enhanced gas sensing performance to H 2 S

• Published in: Journal of hazardous materials 2020-03, Vol.385, p.121570
• Main Authors: Sui, Lili, Yu, Tingting, Zhao, Dan, Cheng, Xiaoli, Zhang, Xianfa, Wang, Ping, Xu, Yingming, Gao, Shan, Zhao, Hui, Gao, Yuan, Huo, Lihua
• Format: Article
• Language: English
• ISSN: 1873-3336
• DOI: 10.1016/j.jhazmat.2019.121570

Hierarchical and heterogeneous CuO/NiO nanowall arrays were in situ grown on ceramic tubes via a facile template-free hydrothermal route, and then were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nitrogen adsorption-desorption techniques. The resultant composites exhibit network-like CuO/NiO array structures constructed by interconnected porous nanosheets, in which the decoration of CuO nanoparticles in NiO nanowall arrays was confirmed by XRD, XPS and TEM analyses. The 2.84 at % CuO decorated NiO sensor exhibits excellent sensing properties at 133 °C. The response to 5 ppm H S attains 36.9, which increases as high as 5.6 times compared to the NiO one. The detection limit to H S is further decreased from 1 ppb for the pure NiO sensor to 0.5 ppb. The CuO/NiO sensor shows a wide linear range from 50 to 1000 ppb, good repeatability, selectivity and long-term stability, which is expected to be a candidate for ppb-level H S detection in real and complex environment of industrial production. Furthermore, the dominant H S sensing mechanism is discussed from the view of the homo- and hierarchical architecture of the CuO/NiO arrays as well as the chemical and electronic sensitization effects of CuO decoration.