Nanorods embedded metal oxide based sensor with ZnO (002) dominant facet for the selective sensing of H2S gas at room temperature

ZnO/TiO 2 /CdO/CuO nanocomposite was synthesized for the gas sensing application by sol-gel co-precipitation method. Thick films of synthesized nanocomposites were deposited using the doctor blade method. It was CuO incorporation that transformed the spherical structure into nanorods embedded in the spherical nanoparticles. The preferential growth of the surface along the (002) facet is observed in the XRD pattern. The significant increase in surface area and mesoporous surface is evident from the BET isotherm. A substantial increase in the adsorbed and vacant oxygen was observed in the O1s spectra. The heterojunction between the different metal oxide was observed in the HRTEM micrographs. Nanorod embedded mesoporous surface revealed a remarkably fast response time of 4.35 s. The role of (002) polar facet together with engineered p-n heterojunction based mesoporous surface having high surface area of 26.43 m 2 /g for room temperature based H 2 S gas sensor, highlights its potential for advanced gas sensor application.