A STUDY OF THE CHARACTERISTICS AND SELECTION OF DOPED MATERIALS FOR NiO TO OPTIMIZE GAS SENSING

Gas sensing of hazardous has become a great challenge for several decades. Recently, technical and industrial advancements uninterruptedly produce the emission of hazardous and poisonous gases that are detrimental to human life as a consequence gas detecting devices that are extremely sensitive and selective to such gases are in a high demand. Presently, gas sensors based on p-type NiO are attracting more attention, because of its outstanding repeatability, high specific surface areas, strong sensitivity, cheap cost and environmental friendly. Herein, we evaluated the various production techniques on p-type NiO nanostructures and their use as gas sensors. The basic gas sensing process linked to the p-type NiO is briefly described. The impacts of noble metals, transition metals, and transition metal dichalcogenide and phosphors materials on the NiO gas sensing performance are also examined in depth. With various level of doping, heterostructure NiO depicts improved sensing performance for gases like HCHO, NH₃, NO₂, C₂H₅OH and H₂. The arrangement of different semiconductor metal oxides to create heterostructures which further enhance the selectivity and sensitivity of the sensing parameters is also addressed. Heterostructure NiO has enhanced sensing capability for gases such as HCHO, NH₃, NO₂, C₂H₅OH, and H₂ with varying levels of doping. There are many literatures on heterostructures linked to NiO based sensor significantly in last decade. The current work will aid researchers in the selection of doped materials for NiO gas sensors in order to enhance sensitivity.