Photocatalytic Degradation of Methylene Blue Using Zinc Oxide Nanorods Grown on Activated Carbon Fibers

Abstract

In this work, the synthesis, characterization, and photocatalytic performance of zinc oxide/activated carbon fiber nanocomposites prepared by hydrothermal method were investigated. Zinc oxide nanoparticles (ZnO-NP) were deposited as seeds on porous activated carbon fiber (ACF) substrates. Then, zinc oxide nanorods (ZnO-NR) were successfully grown on the seeds and assembled on the fibers’ surface in various patterns to form ZnO-NR/ACF nanocomposites. The nanocomposites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrometry, UV–vis diffuse reflectance spectra (DRS), and Brunauer–Emmett–Teller (BET) surface area analysis. SEM images showed that brush-like and flower-like ZnO-NR patterns were grown uniformly on the ACF surface with sizes depending on the ZnO-NP concentration, growth time, and temperature. The FTIR spectrum confirmed the presence of the major vibration bands, especially the absorption peaks representing the vibration modes of the COOH (C = O and C = C) functional group. Adsorption and photocatalytic activities of the synthesized catalytic adsorbents were compared using methylene blue (MB) as the model pollutant under UV irradiation. ZnO-NR/ACF nanocomposites showed excellent photocatalytic activity (~99% degradation of MB in 2 h) compared with that of bare ZnO-NR and ACF. Additionally, a recycling experiment demonstrated the stability of the catalyst; the catalytic degradation ratio of ZnO-NR/ACF reached more than 90% after five successive runs and possessed strong adsorption capacity and high photocatalytic ability. The enhanced photocatalytic activities may be related to the effects of the relatively high surface area, enhanced UV-light absorption, and decrease of charge carrier recombination resulting from the synergetic adsorption–photocatalytic degradation effect of ZnO and ACF.

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.…”

Effect of hydrogen-related shallow donor on the physical and chemical properties of Ag-doped ZnO nanostructures

“…ZnO has a stable wurtzite hexagonal structure with lattice constants a = 3.250 A ˚and c = 5.207 A ˚ [4]. According to these properties, ZnO NPs are used in different applications, such as solar cells [5], optoelectronic devices [6], gas sensors [7], biosensors [8], light-emitting devices [9], and photocatalysis [10]. Many physical and chemical parameters control the synthesis of the ZnO NPs size and morphology, such as solvent pH [11], synthesized solvents [12], annealing temperature [13], and dopant materials [14].…”

Interfacial Grown Zinc Oxide Origami Structure for Broadband Visible Light Driven Photocatalysts

“…The dilemma of the IDLs is that on the one hand they can improve the light absorption in the sub‐bandgap visible range, generate carriers via the IDLs, and are therefore beneficial for the photocatalytic processes, on the other hand, they serve simultaneously as recombination centers, through which the photogenerated electrons and holes recombine with each other, and do not reach to the surface of the photocatalysts, and therefore are detrimental for the photocatalytic processes. This is the main reason why some photocatalysts show light absorption in the visible range, [ 15 ] however no or very limited photocatalytic activity is shown.…”