The application of ZnO/SiO₂nanocomposite for the photocatalytic degradation of a textile dye in aqueous solutions in comparison with pure ZnO nanoparticles

Abstract

A B S T R A C TOne of the major disadvantages of the application of ZnO nanoparticles as photocatalyst in photocatalytic systems is photoinstability due to the photocorrosion under UV light irradiation resulting in the significant reduction in their photocatalytic activity. Therefore, in the present study, SiO 2 nanopowders were incorporated into the ZnO nanoparticles to enhance their photocatalytic activity for the decolorization of methylene blue (MB) dye in comparison with pure ZnO/UV process. The efficiency of UV/ZnO/SiO 2 process was compared with UV/ZnO process for the decolorization of MB dye and the removal of chemical oxygen demand (COD). The effect of various amounts of SiO 2 (5, 10, and 15%) incorporated into ZnO nanoparticles was studied. At optimal SiO 2 loading of 10%, the decolorization efficiency of MB and the removal of COD were obtained to be 100 and 81%, respectively. However, using UV/ZnO process at the same operational conditions, the decolorization efficiency of MB and the removal of COD were 66 and 44%, respectively. An initial pH of 7 and initial dye concentration of 25 mg/L were chosen as optimal experimental conditions. It can be stated that the incorporation of SiO 2 nanopowders into the ZnO nanoparticles would be beneficial for enhancing their photocatalytic activity.

Ultrasound-assisted sorption of Pb(ii) on multi-walled carbon nanotube in presence of natural organic matter: an insight into main and interaction effects using modelling approaches of RSM and BRT

“…A scanning electron microscope coupled with an energydispersive X-ray microanalyzer (SEM/EDX, model) was used to study the surface morphology and surface elemental compositions of the MWCNTs. 22 The adsorbent was also structurally and chemically characterized with X-ray diffraction (XRD, model). The pH value at the point of zero charge (pH pzc ) of MWCNT was determined experimentally.…”

Rice Husk for Photocatalytic Composite Material Fabrication

“…The ZnO/SiO 2 photocatalyst was fabricated to give final mass of 3 g with 95/5, 90/10, 85/15 weight ratio, as described in previous studies [4,7]. The fabrication was conducted in distilled water, while assay was performed in two different solvents, i.e., distilled water and methanol.…”

“…However, when SiO 2 was added, the degradation increased and showed better results compared to pure ZnO. The addition of SiO 2 to ZnO achieved optimum photocatalytic activity at ZnO/SiO 2 90/10 weight ratio with 99% dye degradation efficiency [4].…”

“…The results indicated good results when the composite was used to degrade methylene blue with synthetic SiO 2 made from rice husk as the supporting material. Therefore, the present study aims to fabricate ZnO/SiO 2 with less agglomeration [4].…”

Magnetic titanium/carbon nanotube nanocomposite catalyst for oxidative degradation of Bisphenol A from high saline polycarbonate plant effluent using catalytic wet peroxide oxidation

“…for decomposition of recalcitrant compounds. The advantages of AOPs can be summarized to the simplicity of the required equipment, the operation at mild conditions and the capability to degrade a wide range of organic pollutants to the extent of mineralization [11][12][13][14][15][16][17]. In this sense, catalytic wet peroxide oxidation (CWPO) is an AOP based on the transfer of electrons from an appropriate catalyst to hydrogen peroxide (H 2 O 2 ) molecules in order to accelerate its catalytic decomposition into hydroxide ions (OH − ) and hydroxyl radicals (HO % ) (E 0 = 2.73 V), as given in Eq.…”