Photocatalytic degradation of Dyes in Water by Analytical Reagent Grade Photocatalysts – A comparative study

Abstract

<p><strong>Abstract.</strong> In a search of low cost photocatalyst for dye degradation we have evaluated photocatalytic activity of the Analytical Reagent (AR) grade ZnO, TiO<sub>2</sub> and SnO<sub>2</sub>. The photocatalytic activity was evaluated towards the decolourization of structurally diverse dyes such as crystal violet, basic blue and methyl red under solar irradiation and compared with benchmark Degussa P-25 (TiO<sub>2</sub>) photocatalyst. The received metal oxides were characterized by the different physicochemical methods of analysis. Powder XRD analysis showed that these metal oxides are polycrystalline in nature and crystallized in different crystalline phases. The crystalline phases of these oxides were found to be hexagonal for ZnO, tetragonal for TiO<sub>2</sub> and rutile for SnO<sub>2</sub>. Particle morphology was analysed through SEM imaging and it showed that these oxides consists of different particle morphologies and have different particle sizes. Band gap was evaluated from diffuse reflectance spectra and it was found to be 3.24, 3.20 and 3.66 eV respectively for ZnO, TiO<sub>2</sub> and SnO<sub>2</sub>. Among the three AR grade oxides, ZnO exhibited highest photocatalytic activity which is even higher than Degussa P-25 (TiO<sub>2</sub>) photocatalyst. About 20 % enhancement in the photocatalytic activity of AR grade ZnO was observed when silver metal loaded of on ZnO surface.</p>

Characterization of the Efficiency of Photo-Catalytic Ultrafiltation PES Membrane Modified with Tungsten Oxide in the Removal of Tinzaparin Sodium

“…These results are consistent with data reported by previous research [48,49]. In addition, the photo-generated electrons can be trapped by the oxygen vacancies in the oxide, reducing the electron-hole recombination effect and enhancing the photocatalytic activity of WO 2.89 nanoparticles [50]. However, UV light irradiation had a low effect on the neat membrane flux.…”

Photocatalytic oxidative degradation of hydrocarbon pollutants in refinery wastewater using TiO2 as catalyst

“…An important aspect of the AOPs is the application of photocatalysts among which SnO 2 , WO 3 , CeO 2 , Fe 2 O 3 , ZnO, ZnS, CdS, SiO 2, and TiO 2 are noteworthy (Saien & Shahrezaei, 2012; Shinde, Tambade, Chaskar, & Gadave, 2017). TiO 2 is a preferred catalyst attributed to its high activity, easy availability, cost‐effectiveness, and convenient recovery from the treated wastewater (Abdelwahab, Amin, & El‐Ashtoukhy, 2009).…”

Photocatalytic degradation of coomassie blue G-250 by magnetic NiFe2O4/ZnO nanocomposite

“…The effect of initial dye concentration on the photocatalytic degradation rate for the abovementioned cases can be described by the first-order kinetic model. The constant rate for each photocatalyst was calculated according to Langmuir's relation (3).…”

“…dyes end up in wastewater streams. The rapid industrial growth has caused environmental pollution (in particular, water contamination) due to the release of toxic compounds such as textile dyes, rubber, plastic, aromatic materials, and paper, which can cause irreparable damage to human cells, leading to diseases such as cancer [1][2][3][4]. The presence of dyes and pigments in water resources has created significant problems that cannot be resolved appro-priately by conventional water treatments.…”