3D sulfonated graphene hydrogel for enhanced chemical sensing

摘要

One-step, hydrothermal synthesized 3D sulfonated reduced graphene oxide hydrogel (S-RGOH) is employed to fabricate a chemical sensor with high sensitivity, good selectivity, fast response and reversibility toward several gases. Compared with unmodified RGOH counterparts, the 3D NaHSO3 functionalized S-RGOH sensor exhibits 61.3 and 58.9 times higher responses to NO2 and NH3 respectively. A low limit of detection (LOD) of 4.1 ppb and 1.48 ppm for NO2 and NH3, respectively, has been achieved. The sensor exhibits fast and complete recovery at room temperature. Importantly, for the first time, the characteristics of a linear fitted response-temperature relationship are exploited to discriminate many different gases. An integrated microheater is deployed to modulate substrate temperature rapidly with low power consumption.