الفهرس 
Introduction and Object of Investigation
Object of investigationOnly 14 pages are availabe for public view
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Abstract
ZnO, TiO2 and ZnO-TiO2 nanoparticles possess high
photocatalytic reactivity in degrading various organic pollutants;
however, the law surface area, wide band gap energy and the
photocorrosion severely hinder its industrial application. One of the
recent challenges is concerned with manipulation of novel mesoporous
photocatalyst with high surface area and good photocatalytic stability.
In this research work, a novel series of mesoporous Au/ZnO, Au/TiO2
and Au/ZnO-TiO2 nanoparticles containing 0-10 wt% Au was prepared
by microwave facile sol-gel route using PVP as pore and structure
directing agent. The structural, crystalline, optical and the nanostructure
features were investigated by X-ray diffraction [XRD], N2-adsorptiondesorption
isotherm, Diffuse reflectance spectra [DRS],
Photoluminescence (PL), Field emission scanning electron microscope
[FESEM] and high resolution transmission electron microscopy
[HRTEM]. It is clear from FESEM and HRTEM that gold
nanoparticles are incorporated uniformly on the surface of ZnO and
TiO2 filling theirs pores. DRS analysis confirms the pronounced
reduction of band gap energy upon addition of gold nanoparticles
revealing the positive shift of the photocatalytic response to visible
region. It is obvious to notice that the photocatalytic reactivity of
Au/ZnO and Au/TiO2 nanoparticles in degrading methylene blue is
nearly twice of that of ZnO which can be attributed to the greater
ability of Au to accept electron from ZnO and TiO2 conduction band,
which in turn reducing the recombination of photoinduced electron–
hole couples. Various scavengers as KI, isopropanol, benzoquinone and
methyl viologen are performed in degradation of methylene blue dye to
investigate the reactive species in the degradation process.
Conclusively, it can be emphasized without doubt that these Au/ZnO
and Au/TiO2 nanoparticles would have considerable impact on future
development of hybrid photocatalysts for efficient photocatalytic
degradation of various organic pollutants.
Keywords: Au/ZnO and Au/TiO2 nanoparticles, PVP, Methyl viologen
scavenger, Hexagonal bipod structure, Methylene blue degradation