Photocatalysis with the Use of ZnO Nanostructures as a Method for the Purification of Aquatic Environments from Dyes

Abstract

The papers devoted to the purification of aquatic environments from industrial contaminants with the use of ZnO based nanosized photocatalysts in the period of 2018–2020 are analyzed. The data published in these papers have made it possible to determine the dye ( V ) destruction rate used further as a photocatalytic activity criterion. As shown by the comparative analysis of the photocatalytic activity of the studies structures, the highest rates of water purification from industrial azodye contaminants are demonstrated by hybrid ZnO/Au structures. At a destruction rate of V = 10%/min, the ZnO/Au structures are much better than all the other considered types of catalysts due to their morphology, low recombination rate of photogenerated electron-hole pairs, and nanoparticles with an absorption spectrum close to the solar spectrum. The review of literature data shows that the greatest attention of researchers in the considered time period is focused on the problem of the purification of water sources from industrial contaminants and, first of all, azodyes. Essential attention is also paid to the technological approaches applied by the authors to increase the photocatalytic activity of ZnO based nanostructures.

The effect of Ag doping on the structure, optical, and electronic properties of ZnO nanostructures deposited by atmospheric pressure MOCVD on Ag/Si substrates

“…Intrinsic n-type doping and energy band levels make it suitable for substitution of indium tin oxide as transparent electrode material [2][3][4]8]. Besides, ZnO is considered as a candidate for photovoltaic applications in the near UV spectral region, for sensing [4,9,10], as well as a promising photocatalyst, because of its strong oxidation ability and photocatalytic activity comparable to the benchmark TiO 2 [11,12]. The properties of ZnO can be further tuned by numerous dopants [13][14][15][16].…”

Simultaneous decolorization of anionic and cationic dyes by 3D metal-free easily separable visible light active photocatalyst

“…These wastewaters contain a variety of organic and inorganic contaminants (Liu et al 2021 ). Synthetic organic dyes are one of the largest groups of organic contaminants because of their extensive use in several industries (Kasumov et al 2021 ; Nour et al 2021 ). The features of synthetic dyes such as bio-recalcitrance, toxicity, carcinogenicity, mutagenicity, and light absorbance make them harmful to humans and aquatic environment (Kasumov et al 2021 ; Nour et al 2021 ; Zhang et al 2021 ).…”

“…Synthetic organic dyes are one of the largest groups of organic contaminants because of their extensive use in several industries (Kasumov et al 2021 ; Nour et al 2021 ). The features of synthetic dyes such as bio-recalcitrance, toxicity, carcinogenicity, mutagenicity, and light absorbance make them harmful to humans and aquatic environment (Kasumov et al 2021 ; Nour et al 2021 ; Zhang et al 2021 ). Therefore, several treatment technologies for the removal of synthetic organic dyes from contaminated water have been evaluated and developed (El Bendary et al 2021 ).…”