Visible light-activated room temperature NH3 sensor base on CuPc-loaded ZnO nanorods

• Published in: Sensors and actuators. B, Chemical Chemical, 2021-01, Vol.327, p.128911, Article 128911
• Main Authors: Huang, Jinyu, Jiang, Dongting, Zhou, Jiaxi, Ye, Jiexiong, Sun, Yiling, Li, Xuejin, Geng, Youfu, Wang, Jiaqi, Du, Yu, Qian, Zhengfang
• Format: Article
• Language: English
• Subjects: Ammonia; CuPc loaded; Electron microscopy; gas sensor; Gas sensors; Illumination; Light; Light irradiation; Microscopy; Nanorods; Photoelectrons; Room temperature; Selectivity; X ray photoelectron spectroscopy; Zinc oxide; ZnO nanorods
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2020.128911

CuPc-doped ZnO nanorods have been prepared by one-step microwave-assisted solvothermal method. Unusually, the red-light activated sensor based on CuPc/ZnO displays higher response, better selectivity, faster response-recovery behavior, superior humidity resistance and ultralow detection limit towards NH3 at room temperature compared to CuPc/ZnO in the dark condition and previously reported ZnO-based sensor. Such good sensing performance could be owing to its high adsorption capacity to NH3, fast moving speed of the electrons, as well as high contents of chemisorbed oxygen derived from electrons transfer from the CuPc to ZnO under red light illumination. [Display omitted] •CuPc/ZnO nanorods were synthesized via one-step microwave assisted hydrothermal method.•CuPc/ZnO sensor shows high response, excellent selectivity, rapid response/recovery rate, good humidity resistance and low detection at 27 °C under red light illumination.•These properties are due to fast moving speed of the electrons, and enhanced chemisorbed oxygen derived from electrons transfer from CuPc to ZnO under red light illumination. A one-step microwave-assisted hydrothermal synthetic approach was used to synthesize CuPc-loaded ZnO nanorods. Several characterization techniques were applied to analyze the compositional, structural and morphological information of the products, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV − vis spectrophotometer (UV-vis) and X-ray photoelectron spectroscopy (XPS). Both pure ZnO and CuPc-loaded ZnO were characterized in terms of their gas sensing performances towards various gases under light illumination. The results indicated that CuPc/ZnO sensor delivers excellent sensitivity and selectivity towards ammonia, accompanied with rapid response/recovery rate, remarkable humidity resistance and a low detection limit down to 0.8 ppm at room temperature under red light illumination. This work will open-up new vistas in the development of room temperature gas sensors based on wide-band gap semiconductors with visible-light irradiation.