Selective hydrogen sulfide (H2S) sensors based on molybdenum trioxide (MoO3) nanoparticle decorated reduced graphene oxide

This paper investigates a selective method of sensing hydrogen sulfide using molybdenum trioxide (MoO3) nanoparticle decorated graphene oxide (GO). Reduced graphene oxide was synthesized from natural graphite (NG) by the modified Hummer׳s method and decorated with the MoO3 nanoparticles. Sensors were fabricated by the spin coating of MoO3-decorated rGO between Pt electrodes on alumina substrate (Al2O3). In comparison with pristine rGO sensor, the MoO3–rGO chemiresistors have a clear response to hydrogen sulfide down to 50 ppm at 70 °C. Thermal characterization of the sensor is studied. Results show that the fabricated devices have the maximum gas response at about 160 °C. Selectivity tests indicated that these sensors have poor respond to interfering analytes such as ethanol, carbon monoxide and nitric oxide. Furthermore, the effect of MoO3 content and graphene oxide suspension concentration on the sensor response is investigated. Hereby it is shown that the sensor content of 3 wt% MoO3 and of 5 mg/ml of GO suspension concentration has the highest sensitivity. Decorated reduced graphene oxide chemiresistors offer advantages such as remarkable potential for mass production due to their ease of manufacturing, good performance, and significant selectivity.