Hierarchical nanoflower-like Nickel hydroxide/reduced graphene oxide (Ni(OH)2/rGO) was synthesized through chemical deposition method on Ni foam. The nanoflower like structure was obtained which comprises of ultrathin nanosheets or nanopetals containing porous nanostructure. Further, the addition of rGO enhances the electrical conductivity of synthesized material which exhaustively exploited during proton transfer process. The Ni(OH)2/rGO nanocomposite exhibited excellent NOx gas sensing performance, such as high response time, sensitivity. © Engineered Science Publisher LLC 2022.