Design,Construction And Photocatalytic Performence Of Cobalt/Nickel Compounds Micro/Nanostuctured Materials

As the pollution of the environment becomes more and more serious,the production,storage and application of clean energy,and degradation of organic pollutants have become effective measures for the environmental improvements.Photocatalytic hydrogen generation is considered as an effective route to solve the shortage of energy,thus study on high-efficient photocatalysts has become one of the hottest topics of current research.Due to their low cost,easy synthesis and high photocatalytic activity,nickel compounds and cobalt compounds have become one of the popular subjects in the field of photocatalysis.For this reason,investigation on the design,construction,and photocatalytic properties of cobalt and nickel compounds micron/nanomaterials is a valuable and important subject of study.In this thesis,the PVP/Ni?CH₃COO?₂ composite nanofibers were formed by electrospinning technique,and then NiO solid nanofibers and NiO hollow nanofibers were obtained by calcination of PVP/Ni?CH₃COO?₂.After that,through the methods of double-crucible phosphating method and double-crucible selenization method,NiO hollow nanofibers were transformed to Ni2P nanoparticles and Ni3Se4 monodisperse particles.Meanwhile,NiO and Co3O4 nanowires-in-nanotubes structured nanofibers were first synthesized by electrospinning and two stage calcination of PVP/Ni?CH₃COO?₂ and PVP/Co?CH₃COO?₂ composite nanofibers.Then,CoSe2 microrods were prepared by double-crucible selenization of Co3O4 nanowires-in-nanotubes structured nanofibers.The as-prepared oxides,selenides,and phosphide samples were characterized by XRD,SEM,EDX and TEM,etc.In addition,the photocatalytic activity of the samples was evaluated by degradation rate of Rh B and the hydrogen production rate.The results show that the hydrogen evolution rates of NiO nanowire-in-nanotube structure nanofibers,NiO hollow nanofibers,Ni2P nanoparticles,Ni3Se4 monodispersed particles and CoSe2 microrods were respectively 622,471.6,237.6,417.5 and 1005?mol·h^-1 under visible light irradiation?the mass of catalyst is 0.1 g?.When Ni2P nanoparticles were used as catalyst,the degradation rate of Rh B solution reached 96%after 140 minutes UV light irradiation;and the degradation rates to Rh B of Ni3Se4 monodispersed particles and CoSe2 microrods were respectively 65%and 35%after UV light irradiation for 240 minutes.Some meaningful results have been obtained in this dissertation,which lay a good foundation for the further research on the construction and properties of the micro/nanostructured materials of cobalt and nickel compounds.