3D porous α-Ni(OH)2 nanostructure interconnected with carbon black as a high-performance gas sensing material for NO2 at room temperature

Abstract

Three dimensional (3D) α-Ni(OH)₂/carbon black composite (NiCB) was synthesized by a simple refluxing method using sodium dodecyl benzene sulfonate (SDBS) as the template and intercalation layer. NiCB with 20 mg carbon black (NiCB20) exhibited a fast response time of 2 s to 100 ppm NO₂ at room temperature (RT). This type of 3D composite exhibited a flower-like nanostructure, which consisted of α-Ni(OH)₂ nanoflakes and CB nanoparticles decoration at the centre of the flower structure, and featured a high surface area (175.1 m² g⁻¹). A possible gas sensing mechanism was also discussed. The enhanced gas sensing properties could be ascribed to the synergism of the highly porous structure, high specific surface, and interactions between high conductivity of the CB and 3D α-Ni(OH)₂ nanoplane, which was advantageous for gas to diffuse and adsorb–desorb onto the surface of the NiCB20. The high performance of α-Ni(OH)₂/CB sensors described herein demonstrates them to be a prospect material in environmental monitoring of NO₂.