N-doped reduced graphene oxide for room-temperature NO gas sensors

Yu-Sung Chang; Feng-Kuan Chen; Du-Cheng Tsai; Bing-Hau Kuo; Fuh-Sheng Shieu

doi:10.1038/s41598-021-99883-9

N-doped reduced graphene oxide for room-temperature NO gas sensors

Sci Rep. 2021 Oct 20;11(1):20719. doi: 10.1038/s41598-021-99883-9.

Authors

Yu-Sung Chang¹, Feng-Kuan Chen¹, Du-Cheng Tsai¹, Bing-Hau Kuo¹, Fuh-Sheng Shieu²

Affiliations

¹ Department of Materials Science and Engineering, National Chung Hsing University, Taichung, 40227, Taiwan, Republic of China.
² Department of Materials Science and Engineering, National Chung Hsing University, Taichung, 40227, Taiwan, Republic of China. fsshieu@dragon.nchu.edu.tw.

Abstract

In this study, we use nitrogen-doped to improving the gas-sensing properties of reduced graphene oxide. Graphene oxide was prepared according to a modified Hummers' method and then nitrogen-doped reduced graphene oxide (N-rGO) was synthesized by a hydrothermal method using graphene oxide and NH₄OH as precursors. The rGO is flat and smooth with a sheet-like morphology while the N-rGO exhibits folded morphology. This type of folding of the surface morphology can increase the gas sensitivity. The N-rGO and the rGO sensors showed n-type and p-type semiconducting behaviors in ambient conditions, respectively, and were responsive to low concentrations of NO gases (< 1000 ppb) at room temperature. The gas-sensing results showed that the N-rGO sensors could detect NO gas at concentrations as low as 400 ppb. The sensitivity of the N-rGO sensor to 1000 ppb NO (1.7) is much better than that of the rGO sensor (0.012). Compared with pure rGO, N-rGO exhibited a higher sensitivity and excellent reproducibility.