A high-sensitivity H2S gas sensor based on optimized ZnO-ZnS nano-heterojunction sensing material

• 作 者: Pei Ding Dongsheng Xu Nan Dong Ying Chen Pengcheng Xu Dan Zheng Xinxin Li
• 机 构: School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418,
• 出 处: 中国化学快报（英文版）
• 发表日期: 2020年8期
• 关键词: ZnO-ZnS heterojunction Hydrogen sulfide Gas sensor Sensitivity detection Selecti

This paper reports a high-performance H2S gas sensing material that is made of ZnO nanowires (NWs) modified by an optimal amount of ZnS to form nano-heterojunctions. Compared with the intrinsic ZnO-NWs, the three differently modified nano-heterostructure material ZnO-ZnS-x (x=5, 10, 15) shows significant improvement in sensing performance to H2S at the working temperatures of 100-400 ℃, especially in the low temperature range (<300 ℃). The chemiresistive sensor with ZnO-ZnS-10 sensing-material exhibits the largest response signal to H2S among all the other ZnO-ZnS-x (x=5, 10, 15, 20) sensors. Its response signal to 5 ppm H2S at 150 ℃ is about 2.7 times to that of the ZnO-NWs sensor. Besides, the ZnO-ZnS-10 sensor also features satisfactory selectivity and repeatability at 150 ℃. With the technical advantage attributed to the reduction of the redesigned band gap at the interface between ZnO and ZnS, the ZnO-ZnS heterostructure sensor rather than the traditional ZnO-NWs sensor can be used for high-sensitivity application at low working temperature.