Ovsianytskyi, Oleksandr Nam, Yun-Sik Tsymbalenko, Oleksandr Lan, Phan-Thi Moon, Myoung-Woon Lee, Kang-Bong 2024-01-19T23:30:13Z 2024-01-19T23:30:13Z 2021-09-03 2018-03 0925-4005 https://pubs.kist.re.kr/handle/201004/121653 Herein, we report a highly sensitive and selective H2S gas sensor based on graphene decorated with Ag nanoparticles (AgNPs) and charged impurities fabricated using a simple wet chemical method. Doping on as-grown chemical vapor deposited graphene was achieved by immersion in an aqueous solution of AgNO3/Fe(NO3)(3) for 4 min followed by the decoration with adsorbed AgNPs and charged impurities. The AgNPs utilized in this process were formed by the reduction of Ag+ ions, since the Ag+/Ag-0 reduction potential is higher than that of Fe3+/Fe-0. The above treatment changed the electronic properties of graphene, achieving a dramatic resistivity change in the presence of H2S gas by generating surface sites for its adsorption and dissociation and thus allowing real time H2S level monitoring at ambient temperature with an immediate response. Doped graphene was demonstrated to selectively and repeatedly sense H2S gas within six minutes, with the limit of detection being below 100 ppb. The corresponding mechanism is believed to feature a charge carrier density change of graphene to adsorbate charge transfer, with the sensor surface trapping or releasing electrons upon exposure to H2S gas. (c) 2017 Elsevier B.V. All rights reserved. English ELSEVIER SCIENCE SA OXIDE NANOCOMPOSITES SENSING PROPERTIES ADSORPTION SURFACE DIAMOND SINGLE COPPER FILMS FE Highly sensitive chemiresistive H2S gas sensor based on graphene decorated with Ag nanoparticles and charged impurities Article 10.1016/j.snb.2017.10.128 1 SENSORS AND ACTUATORS B-CHEMICAL, v.257, pp.278 - 285 SENSORS AND ACTUATORS B-CHEMICAL 257 278 285 scie scopus 000418868700032 2-s2.0-85032926239 Chemistry, Analytical Electrochemistry Instruments & Instrumentation Chemistry Electrochemistry Instruments & Instrumentation Article OXIDE NANOCOMPOSITES SENSING PROPERTIES ADSORPTION SURFACE DIAMOND SINGLE COPPER FILMS FE CVD graphene Chemiresistive sensor H2S graphene sensor Graphene doping Silver nanoparticle doping