Nanomaterials-Based Resistive Sensors for Detection of Environmentally Hazardous H2S Gas

The development of nanomaterial-based gas sensors has led to demanding research interest in the last few decades due to their potential for high sensitivity, selectivity, and fast detection of various environmentally hazardous gases. Hydrogen sulfide (H2S) is a hazardous gas normally produced from sewage, mines, petroleum fields, gasoline, natural gas production, etc. In this review, advancements in the development of different metal-oxide semiconductors (MOS) and carbon-based H2S gas sensors are summarised. The commonly investigated materials in MOS are zinc oxide, tin oxide, tungsten oxide, titanium oxide, indium oxide, copper oxide, and composites, and in carbon allotropes, graphene, carbon nanotubes, and fullerene have been tested for H2S gas sensing. The main focus of this review is the description of the various synthesis processes and the morphology of H2S gas sensors by various researchers in order to improve the sensing performance parameters, such as response, sensitivity, selectivity, response time, and recovery time using different materials/catalysts.