TiO2 Immobilized on Fibrous Clay as Strategies to Photocatalytic Activity

Abstract

TiO 2 immobilized in Sepiolite (TiO 2 /Sep) was successfully prepared by the sol-gel technique, with titanium isopropoxide as the precursor for the formation of TiO 2 in the anatase phase calcined at 400 °C. The prepared samples were characterized by X-ray diffraction, Fourier Transform Infrared spectroscopy, Scanning Electron Microscopy coupled to energy dispersive spectroscopy, and thermogravimetric analysis. The results showed that TiO 2 /Sep structure was identified in all characterizations, showing the specific peaks, bands, mass loss, and morphology after the impregnation process. Photocatalytic experiments were performed under UV irradiation with various photocatalyst concentrations and pH effects in the reaction. The prepared samples presented 72% photocatalytic efficiency for eosin (EA) dye discoloration after 150 min under UV light. This efficiency was attributed to the radicals generated from the TiO 2 and the high specific surface area, showing that TiO 2 /Sep is promising candidate in the degradation of organic pollutants.

A Brief Photocatalytic Study of ZnO Containing Cerium towards Ibuprofen Degradation

“…The photocatalyst promoted a higher number of active sites, consequently increasing the concentrations of hydroxyl radicals and superoxides [ 55 ]. However, the radicals can recombine and inhibit the photocatalytic process, and a large amount of suspended material can cause the inhibition of light passage, implying a decrease in the photocatalytic efficiency [ 56 ]. Similar behavior was reported by Wang et al [ 9 ].…”

“…The degradation rate increased with the increase in the number of protons, following the order pH 10 (22%), pH 7 (41%), and pH 3 (47%); therefore, it increased by about 25% compared to the alkaline medium. The low degradation at pH 10 can be attributed to competition between the surface charges of the photocatalyst, which are slightly altered and may be protonated/deprotonated, consuming the hydroxyl radical and consequently decreasing the degradation rate [ 56 , 60 ]. Wang et al [ 9 ] observed that the degradation of IBU was directly affected by the pH of the solution, with the highest degradation rate (49.45%) in acidic pH values.…”

Sustainable Synthesis and Enhanced Photocatalytic Activity of Titanium Oxide-Clay Nanocomposite Toward Persistent Polychlorinated Biphenyl Degradation in Real Samples

“…2, there are an array of 8 main peaks that appeared in FTIR spectrum of TiO 2 -caly nanocomposite sample. the presence three stretching bands between 3800 and 3600 cm -1 are likely assigned to OH groups of absorbed water molecules as well as water coordinated to magnesium or surface of clay structure 32 . The fairly wide peak appread at 3419 cm -1 is attributed to O-H stretching vibration, representing hydroxyl groups of glucose and starch hydrocarbons 33 .…”

“…The peak at 1641 cm -1 likely re ects the presence bending vibration of OH group of water molecules in interlayer of TiO 2 -caly nanostructured. The vibration of Si-O-Si bonds at ngerprint region of1036 and 1461 cm -1 perhaps are representative of sheet-like silicates in clay mineral 32 . Finally, Ti-O bonding of anatase type was appeared at 528 cm -1 and 440 cm -1 bands indicating immobilization of the titania NPs on clay structure 35,36 .…”

Supported TiO2 in Ceramic Materials for the Photocatalytic Degradation of Contaminants of Emerging Concern in Liquid Effluents: A Review

“…Highly crystallized and high porosity anatase samples allow the access of large organic molecules as well as light during the reaction [ 120 ]. pH can influence differently the degradation of contaminants [ 38 , 156 ] because, in acidic or alkaline conditions, the TiO 2 surface can be protonated or deprotonated [ 156 , 157 ].…”