Zhang Yaojun

Preparation of CdS/TiO2NTs Nanocomposite and Its Activity of Photocatalytic Hydrogen Production

Abstract The CdS/TiO2NTs nanocomposite was prepared through ion-exchange and precipitation reactions. The nanostructure properties of the composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance UV-visible absorption spectra (DRUVAS), fluorescence emission spectra (FES) and X-ray fluorescence analyzer (XRF). SEM results revealed that the lamellar sodium trititanate originating from the TiO2 particles individually curled to form the sodium trititanate nanotubes by self-assembled mechanism. The results of XRD, TEM and DRUVAS demonstrated that hexagonal phase CdS with about 8 nm particle size were homogeneously loaded on the surface of anatase TiO2NTs and the absorption edge of the composite was extended to the visible region. The CdS/TiO2NTs composite exhibited the highest activity of hydrogen production (1708 μL/g) by photocatalytic water decomposition in comparison with TiO2NTs and TiO2 powder under visible light irradiation (λ > 400 nm) for 6 h.

A Novel Magnesium Slag-Based Cementitious Nano-Composite for Photocatalytic Degradation of Dye

Abstract A novel alkali-activated magnesium slag-based cementitious nanocomposite (AMSCN) was synthesized by co-loaded NiO and CuO, and employed as a photocatalyst for the degradation of methyl orange dye. The FESEM images reveal that the AMSCN has a nanostructural morphology with average size of about 30 nm. The XRD patterns show that the AMSCN is principally composed of mineralogical phase of calcium silicate hydrate (C-S-H). NiO active species are uniformly dispersed in the form of amorphous phase and CuO emerged nanophase with mean size of 15 nm on the surface of AMSCN. The 10(NiO+CuO)/AMSCN nanocomposite exhibits the highest photocatalytic degradation rate (93%) due to the synergistic effect between the AMSCN matrix and active species of NiO and CuO. The kinetics analysis indicates that the photocatalytic degradation of methyl orange follows the first order reaction kinetics.