Study On Controllable Preparation Of Nickel Matrix Composites And Its Gas Sensing Properties

In this paper, the α-Ni（OH）₂/CB nanoflower with 3D hierarchical structure and NCDHnanosheets with highly mesoporouscomposites were prepared by used of simple reflux and hydrothermal methods.Firstly, By adding of SDBS as the template, Nickel nitrate as Nickel source, urea（CO（NH₂）₂） as precipitants, and composited different quality of Carbon black（CB）, the NCDH nanocomposite with 3D hierarchical structure were synthetized for the first time. The material showed good gas sensing response to NO₂ at room temperature. The formation mechanism and effection of surfactant was discussed, and the performance of mesoporous structure with NiOH interlayer and the role of carbon black in composite materials was studied in-depth. The results demonstrated that 3D flower-like structure were assembled by α-Ni（OH）₂nanoflake. Based on the high electrical conductivity of CB and porous structure of the materials, the conductivity and transmission capacity of the gas were significantly improved, which is effectively improved the material of NO₂ gas sensitive properties and the service lifetime.Secondly, two-dimensional porous NiO-CuO（NiCu） nanosheet was synthesized via the method of hydrothermal-reflux-calcining and without surfactant. Researching about the growth process, the result showed composites have 2D nanosheet structure、high specific surface area and p-p heterojunction formation, which is benefited for electron transmission. The sample with NiCu₁ has the the highest sensitivity and fastest response time to 100 ppm NO₂, sensitivity was 79.16 % and the response time was 2s, its limit level was 1 ppm.In summary, the 3D NiCB nanocomposites with highly mesoporous structure and 2D porousNiCu nanosheet havefast-response to NO₂ at room temperature. It look forward topromising material in gas sensing field.