Co,N-doped GQDs/SnO mesoporous microspheres exhibit synergistically enhanced gas sensing properties for HS gas detection

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 1; no. 19; pp. 1759 - 1767
• Main Authors: Chen, Tingting, Sun, Jianhai, Xue, Ning, Zhang, Xinxiao, Wang, Hairong, Jiang, Kaisheng, Zhou, Tianye, Quan, Hao
• Format: Journal Article
• Published: 17.05.2022
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d2ta00837h

Graphene quantum dots (GQDs) are emerging as one of the promising candidate materials that have the properties of both graphene and semiconductor quantum dots; moreover, they can be dispersed in common solvents and compounded with solid materials for developing high-performance gas sensors. In this work, we prepared cobalt (Co) and nitrogen (N) co-doped GQD-modified SnO 2 composites (Co,N-GQDs/SnO 2 ) by a solvothermal route, in which Co,N-GQDs were prepared by using citric acid, urea and CoCl 2 as the source of the hydrothermal method. The optimal sensor response value toward 100 ppm H 2 S is about 37.3 at 260 °C, which is over 2 times higher than those of pure SnO 2 mesoporous microspheres at 312 °C. In addition, this material has excellent selectivity, good reproducibility, fast response/recovery time (5/11 s to 100 ppm), and ppb-level H 2 S detection ability (1.18 to 50 ppb H 2 S). The superior sensing performance of Co,N-GQDs/SnO 2 can be attributed to the increase of active sites on the surface of the materials and the electrical modulation of Co,N-GQDs. The facial fabrication and outstanding performance make our sensors highly attractive for H 2 S detection and expand the application fields of GQDs. The optimal sensor (Co,N-GQDs/SnO 2 ) response value toward 100 ppm H 2 S is 37.3 at 260 °C, which has superior sensing performance. This can be attributed to the increase of active sites on the surface and the electrical modulation of Co,N-GQDs.