Photocatalytic Degradation of Methylene Blue Using Polymeric Membranes Based on Cellulose Acetate Impregnated with ZnO Nanostructures

Abstract

This paper studied the photocatalytic degradation of methylene blue (MB) using polymeric membrane impregnated with ZnO nanostructures under UV-light and sunlight irradiation. ZnO nanoparticles and ZnO nanowires were prepared using the hydrothermal technique. Cellulose acetate polymeric membranes were fabricated by the phase inversion method using dimethylformamide (DMF) as a solvent and ZnO nanostructures. The structural properties of the nanostructures and the membranes were investigated using XRD, SEM, FTIR, and TGA measurements. The membranes were tested for photocatalytic degradation of MB using a UV lamp and a sunlight simulator. The photocatalytic results under sunlight irradiation in the presence of cellulose acetate impregnated with ZnO nanoparticles (CA-ZnO-NP) showed a more rapid degradation of MB (about 75%) compared to the results obtained under UV-light irradiation degradation (about 30%). The results show that CA-ZnO-NP possesses the photocatalytic ability to degrade MB efficiently at different levels under UV-light and sunlight irradiation. Modified membranes with ZnO nanoparticles and ZnO nanowires were found to be chemically stable, recyclable, and reproducible. The addition of ZnO nanostructure to the cellulose membranes generally enhanced their photocatalytic activity toward MB, making these potential membranes candidates for removing organic pollutants from aqueous solutions.

Sunlight Photocatalytic Performance of ZnO Nanoparticles Synthesized by Green Chemistry Using Different Botanical Extracts and Zinc Acetate as a Precursor

“…The photocatalytic activity of catalysts was tested as follows: first, 0.3 g of each sample was dispersed in 300 mL of 10 mg/l methylene blue solution ( C 0 ), regulating the pH to 10; this value was selected according to previously reported pH optimization results [ 51 ]. Then, the solution was placed in the dark with constant stirring for 45 min to achieve equilibrium of methylene blue adsorption on ZnO nanoparticles before being exposed to radiation [ 32 , 52 ]. Subsequently, samples were taken every 30 min (if the kinetics was fast, samples were taken every 5 min) and centrifuged at 8000 rpm to separate the nanoparticles in suspension; the supernatants were evaluated by UV-Vis spectroscopy at 665 nm, whose wavelength corresponds to the most important band (azo dye content).…”

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

“…The photocatalytic degradation of MO, on the other hand, proceeds with the breaking of the N]N bond, causing the separation of the molecule. [74][75][76][77][78] The radicals then decompose the CH 3 group by attacking the CH 3 -N-CH 3 group. Following that, one of the aromatic rings is released, followed by a series of intermediate processes that result in the nal by-products of CO 2 and H 2 O.…”

Green synthesis of sorbus pohuashanensis/aronia melanocarpa extracts functionalized ZnO nanoclusters and their applications

“…Another mechanism is related to the photocatalytic activity of ZnO NCs: Under the condition of UV or sunlight irradiation, ZnO NCs induce the production of hydroxyl radicals, which could react with dyes, and finally degrade the dyes. Furthermore, the effect is more significantly enhanced when UV irradiation is used [31][32][33]. In our study, the adsorption process for organic dye was performed in dark thus avoiding the possible reaction induced by light.…”