Synthesis and characterization of Cobalt-doped ZnO microstructures for methane gas sensing

• Published in: Applied surface science 2016-02, Vol.363, p.181-188
• Main Authors: Hu, Jie, Gao, Fanqin, Zhao, Zhenting, Sang, Shengbo, Li, Pengwei, Zhang, Wendong, Zhou, Xiongtu, Chen, Yong
• Format: Article
• Language: English
• Subjects: Cobalt; Cobalt-doped; Gas sensing; Gas sensors; Methane; Methane sensor; Microstructure; Morphology; Sensors; X-rays; Zinc oxide; ZnO microstructures
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2015.12.024

•The Co/ZnO microstructures with different Co content have been successfully prepared by hydrothermal method.•The measured results indicate that the presence of Co ion can greatly influence the morphology of ZnO nanostructures.•The as-fabricated Co/ZnO gas sensors exhibit high gas sensing performances at the optimum operating temperature of 140°C.•The methane sensing properties prove that 1wt% Co/ZnO sample exhibited the highest response, fast response/recovery time and low detection limit. Pure and Cobalt doped ZnO microstructures have been prepared by hydrothermal method and calcinations at 600°C. The crystal structure, surface morphology and chemical composition of the samples were determined by X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy, respectively, indicating that the presence of a small quantity of Co ions can greatly affect the morphology of the ZnO nanostructures. When used for methane gas sensing, 1wt% Co/ZnO (CZ1) sensor exhibited the highest response to 100ppm methane at 140°C, which were about 2 times higher than that of pure ZnO samples. Moreover, the 1wt% Co/ZnO sensor also displayed fast response/recovery time (19/27s), low detection limit (50ppb). Thus, the CZ1 microstructures are promising for practical methane sensing applications.