Chapter 8 ZnO / Sepiolite Catalysts – Characterization and Photoactivity Measurements

Sepiolite-supported ZnO catalysts (ZnO-SEP) were prepared and characterized using Xray diffraction (XRD), surface area (BET) measurements, scanning electron microscopy (SEM) with energy-dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectra (UV-vis DRS) techniques. XRD analysis sup‐ plied information about the generation of ZnO nanoparticles. SEM images and elemental mapping scans revealed variations in the surface morphology of the SEP after ZnO load‐ ing. Supported catalysts possessed higher surface areas and pore volumes in comparison to unsupported catalyst (0.25 M ZnO). They also revealed suitable band-gap energies in the UV-A region. XPS analysis confirmed the build-up of ZnO nanoparticles on the SEP matrix with the form of Zn2+ oxidation state. Photocatalytic performances were evaluated in terms of methyl orange (MO) decolorization process following pseudo-first-order ki‐ netics. The repeatability of photocatalytic activity was also tested.

[1]  D. Karamanis,et al.  Dual functionality of TiO2-flyash nanocomposites: Water vapor adsorption and photocatalysis , 2014 .

[2]  D. Karamanis,et al.  A novel photoresponsive ZnO-flyash nanocomposite for environmental and energy applications , 2013 .

[3]  J. Musarrat,et al.  Photocatalytic oxidation of acetaldehyde with ZnO-quantum dots , 2013 .

[4]  A. Mohamed,et al.  Green hydrothermal synthesis of ZnO nanotubes for photocatalytic degradation of methylparaben , 2013 .

[5]  J. Samberg,et al.  Effects of morphology on photocatalytic performance of Zinc oxide nanostructures synthesized by rapid microwave irradiation methods , 2012 .

[6]  A. Mohamed,et al.  Degradation of wastewaters containing organic dyes photocatalysed by zinc oxide: a review , 2012 .

[7]  Shaobin Wang,et al.  ZnO/montmorillonite for photocatalytic and photochemical degradation of methylene blue , 2011 .

[8]  S. Sonawane,et al.  Continuous flow photocatalytic reactor using ZnO–bentonite nanocomposite for degradation of phenol , 2011 .

[9]  M. Tadé,et al.  Combination of adsorption, photochemical and photocatalytic degradation of phenol solution over supported zinc oxide: Effects of support and sulphate oxidant , 2011 .

[10]  S. Kansal,et al.  Photocatalytic decolorization of biebrich scarlet dye in aqueous phase using different nanophotocatalysts , 2010 .

[11]  Veaceslav Ursaki,et al.  Synthesis and characterization of ZnO nanowires for nanosensor applications , 2010 .

[12]  V. Meynen,et al.  ZnO nanoparticles supported on mesoporous MCM-41 and SBA-15: a comparative physicochemical and photocatalytic study , 2010 .

[13]  L. Chow,et al.  Nanofabrication and characterization of ZnO nanorod arrays and branched microrods by aqueous solution route and rapid thermal processing , 2007 .

[14]  A. M. Amat,et al.  Sepiolites as supporting material for organic sensitisers employed in heterogeneous solar photocatalysis , 2007 .

[15]  K. Ariga,et al.  Photocatalytic activity of La-doped ZnO for the degradation of monocrotophos in aqueous suspension , 2007 .

[16]  S. Suárez,et al.  Development of a new Rh/TiO2-sepiolite monolithic catalyst for N2O decomposition , 2006 .

[17]  Wang Dejun,et al.  Effects of noble metal modification on surface oxygen composition, charge separation and photocatalytic activity of ZnO nanoparticles , 2006 .

[18]  Tae Woo Kim,et al.  Heterostructured nanohybrid of zinc oxide-montmorillonite clay. , 2006, The journal of physical chemistry. B.

[19]  T. Albanis,et al.  TiO2-assisted photocatalytic degradation of azo dyes in aqueous solution: kinetic and mechanistic investigations A review , 2004 .

[20]  I. Dékány,et al.  Synthesis of ZnO nanoparticles on a clay mineral surface in dimethyl sulfoxide medium. , 2004, Langmuir : the ACS journal of surfaces and colloids.

[21]  L. Jing,et al.  The surface properties and photocatalytic activities of ZnO ultrafine particles , 2001 .

[22]  Hugo Destaillats,et al.  The Sonochemical Degradation of Azobenzene and Related Azo Dyes: Rate Enhancements via Fenton's Reactions , 2000 .

[23]  V. Renganathan,et al.  Hydroxyl radical mediated degradation of azo dyes: evidence for benzene generation. , 1994, Environmental science & technology.

[24]  E. Teller,et al.  On a Theory of the van der Waals Adsorption of Gases , 1940 .

[25]  M. Bañares,et al.  Nanostructured ZnO/sepiolite monolithic sorbents for H2S removal , 2015 .

[26]  K. Mahesh,et al.  Facile synthesis of heterostructured Ag-deposited SiO2@TiO2 composite spheres with enhanced catalytic activity towards the photodegradation of AB 1 dye , 2015 .