Structural Regulation, Adsorption And Sensing Properties Of NiS And NiO Nanomaterials

3D network structure assembled by NiS nanosheets were successfully synthesized by the simple solution thermal method. And the NiO porous skeletal structure and cubic Ag/NiO octahedron with exposed{111} facets were synthesized through thermal decomposition. Morphologies and structures of these products were characterized by means of X-ray diffraction, scanning electron microscopy, field emission scanning electron microscopy, transmission electron microscopy, IR spectrum, X-ray photoelectron spectra and absorption-desorption porosimetry. The adsorption performance of acid dyes of NiS 3D network structure assembled by nanosheets were studied, and proposed possible mechanism of selective adsorption of acid dyes. Research the sensing properties of NiO skeletal structure prepared at different temperatures and cubic Ag/NiO octahedron with exposed{111} facets under different conditions of doped Ag content, proposed gas sensing performance enhancement mechanism. These research results would provide a base for further research on syntheses of NiO and NiS nanostructures, the physical and chemical properties of NiO and NiS nanostructures and their applications in adsorption performance and gas sensing performance.(1) 3D network structure assembled by NiS nanosheets were successfully synthesized by the simple solution thermal method with nickel chloride as source of nickel, thiourea as a source of sulfur in Si wafer substrate. The selective adsorption properties of the NiS network structure of acid dyes were studied. It was explored the effects of different initial dye concentration and pH of the system on adsorption properties of NiS, finding the larger initial concentration, and closer to 6.9 (IEP) pH of dye solutions are, the better the adsorption performance become. And proposed possible mechanism of selective adsorption of acid dyes.(2) NiO porous three-dimensional framework structure was successfully synthesized by the simple solution thermal method with an ethylene glycol solution of nickel nitrate as the metal source. We obtained Ni-NiO complex structure by changing the reaction temperature, and explored the sensor performance of three-dimensional framework structure of porous NiO and Ni-NiO complex structure. It was found to have excellent gas sensing properties, and a pure phase structure, larger specific surface area, richer pore structure, the better sensing performance. Thus, the three-dimensional framework structure of porous NiO has potential applications in the field of gas sensors.(3) Based on the NiO octahedral structure with exposed{111} plane, we prepared Ag/NiO octahedron with selective deposition Ag on the{111} plane. Sensor performance of Ag/NiO and NiO octahedral structure with exposed{111} plane were studied. It was found that Ag/NiO octahedron had better sensor sensitivity performance than pure NiO octahedron and NiO deposition different Ag contents had different sensor sensitivity. It was explored possible mechanisms that excellent sensing performance was mainly due to NiO octahedron structure exposed a high energy{111} planes. The electric field exists between the Ni-NiO and O-NiO polar crystal surface, and the presence of elemental Ag enhanced the the internal electric field between crystal planes. Under the electric field, electronic migration to the Ni-NiO crystal face, aggregated on the sample surface, and adsorpted amount of free oxygen to enhance the sensing performance of the NiO.