Photocatalytic degradation of a textile dye in aqueous phase over ZnO nanoparticles embedded in biosilica nanobiostructure

Abstract

A B S T R A C TIn the present study, ZnO nanoparticles immobilized on biosilica nanobiostructure were used for the photocatalytic degradation of Acid Red 88 (AR88) in aqueous phase. UV-induced ZnO/biosilica nanocomposite (78.84%) was more efficient than visible light-induced ZnO/biosilica nanocomposite (21.87%). The results of UV-vis diffuse reflectance spectra (DRS) indicated that the enhanced UV-vis absorption of the nanocomposite could be attributed to biosilica support. Increasing the adsorbent dosage from 0.1 to 1.5 g/L caused a sharp increase in the decolorization efficiency from 15.30 to 98.54%, respectively, while further increase in the amount of photocatalyst to 2 g/L led to a little drop in the decolorization efficiency, decreasing to 93.63%. Decreasing the initial AR88 concentration from 70 to 10 mg/L enhanced the apparent reaction rate constant (k ap ) from 0.0078 to 0.1579 min −1 and diminished the consumption of electrical energy (EE 0 ) from 2,813 to 139 kW h/m 3 , respectively. The decolorization and mineralization efficiency of 96.32 and 65.57% were obtained, respectively, thereby confirming an acceptable mineralization of AR88 within 30 min.

Photocatalytic degradation of antibiotic and hydrogen production using diatom-templated 3D WO3-x@mesoporous carbon nanohybrid under visible light irradiation

“…( 2), restrict the application of pure WO3 in photo-degradation of different contaminants under visible light irradiation. Interestingly, the integration of MC and WO3-x fabricates an superior nanohybrid photocatalyst which leads to the almost complete degradation of CFZ (98.7%) under the same operational conditions according to the following equations (Darvishi Cheshmeh Soltani et al 2016):…”

Three-Dimensional Rice Straw-Structured Magnetic Nanoclay-Decorated Tripolymeric Nanohydrogels as Superadsorbent of Dye Pollutants

“…Therefore, researchers are highly motivated to develop cost-effective simple technique to treat those toxic pollutants. Among different removal strategies, adsorption is considered as the simple and best because of its low cost, ease of operation, high efficiency, regeneration, and insensitivity to toxic substances , over other techniques such as ozonation, coagulation-flocculation, advance oxidation, photochemical degradation, and membrane technology . Apart from the choice of removal strategies, designing of low cost, eco-friendly, and more efficient adsorbent is another insight of water remediation.…”

Fabrication of a zinc oxide/alginate (ZnO/Alg) bionanocomposite for enhanced dye degradation and its optimization study

“…Electronegativity values of ZnO is 5.79 eV. 70 On the hydrogen scale, E e is the energy of free electrons (∼4.5 eV), and E g is the bandgap energy of semiconductors. The sample does not decolorize when exposed to visible light in the presence of pure ZnO because ZnO has a bandgap of 3.2 eV.…”