Studies On Preparation Of Nano Carbon/semiconductor Material And Its Photocatalytic Performance

With the rapid development of industry, the environmental pollution has becomemore and more serious. As semiconductors can be used to treat organic pollutants,they have attracted considerable attention. However, it has still not been applied inpractice due to its low visible light utilization rate and higher recombination rate ofphotoinduced electron-hole pairs. Under this background, we aim to develop nanocarbon/semiconductor materials based on carbon with excellent electronicconductivity and high specific areas. The synthesized strategy and their photocatalyticperformance were also analyzed. It mainly focusses on the following aspects:(1) Ordered mesoporous ZnS rods decorated graphene nanocomposites weresuccessfully synthesized by wet chemical method with the assistance of microwave.Scanning electron microscopy and transmission electron microscopy confirmed thatthe as-formed ordered mesoporous ZnS rods, about50nm in diameter and severalhundreds of nanometers in length, were distributed on graphene sheets. Fluorescentemission spectra and X-ray photoelectron spectroscopy confirmed that ZnS andgraphene intimately contact with each other. The effects of reaction temperature,reaction time and mass content of graphene oxides on the microstructure andphotocatalytic activity were investigated. The experimental results indicated that thisnanocomposites can decompose MO effectively and it is ascribed to the combinationof excellent conductivity of graphene and high specific area of mesoporous ZnS.(2) The nanocomposites of reduced graphene oxides (rGO) loaded-ZnS/CuSheteronanostructures had been successfully prepared. Scanning electron microscopyand transmission electron microscopy confirmed that ZnS/CuS heteronanostructureswere decorated on the surface of rGO. X-ray photoelectron spectroscopies of thesamples before and after photocatalytic reaction confirmed visible light irradiationinduced interfacial charge transfer from the valence band (VB) of ZnS to CuS clusters.The effects of reaction temperature, reaction time and mass content of graphene onthe microstructure and photocatalytic activity were investigated. The experimentalresults reveal that the high visible light photocatalytic activity is realized due to thephotoinduced interfacial charge transfer inside the heteronanostructures.(3) Carbon nanotubes/reduced graphene oxides (CNTs/rGO) implanting cuprousoxide (Cu2O) composite spheres had been successfully prepared via an electrostatic self-assemble with microwave-assistance. Scanning electron microscopy andtransmission electron microscopy observations confirmed that the hybrid of CNTs andrGO were implanted into Cu2O matrix and formed a three-dimensional embeddedmicrometer sphere structure. The contribution of CNTs, GO to the formation ofspheres was analyzed and the possible formation mechanism of this architecture werealso proposed. The effects of reaction temperature, proportion of carbonnanotubes/graphene oxides and mass content of carbon nanotubes/graphene on themicrostructure and photocatalytic activity were investigated. The experimental resultsindicated that the high visible photocatalytic performances were attributed to carbonmaterials implanted structure.(4) CNTs/rGO sphere decorated with CuxO nanoparticles composite wassuccessfully synthesized by spray drying and post-calcinating method. Scanningelectron microscopy and transmission electron microscopy confirmed that CNTs/rGOformed a spherical micrometer structure and CuxO (x=1or2)nanoparticles weredecorated on their surface. The effects of decomposition temperature, the proportionof carbon nanotubes/graphene oxides and mass content of carbon nanotubes/grapheneon the microstructure and photocatalytic activity were investigated. The experimentalresults indicated that CNTs/rGO sphere decorated with CuxO nanoparticles enhancedphotocatalytic performance as well as simplified technological process and improvedproduction efficiency...