Efficient magnetic hybrid ZnO-based photocatalysts for visible-light-driven removal of toxic cyanobacteria blooms and cyanotoxins

Enhanced Photocatalytic Removal of Cyanotoxins by Al-Doped ZnO Nanoparticles with Visible-LED Irradiation

“…The complete mineralization of both cyanotoxins was confirmed after 380 min of visible-LED irradiation. At the same time, the reported values are highly competitive with outcomes achieved with state-of-the-art photocatalytic techniques for mineralizing cyanotoxins [ 9 , 12 , 13 , 31 , 35 , 36 , 37 ]. By contrast, most studies on the photocatalytic degradation of cyanotoxins have not involved analyzing mineralization but only the degradation of the initial cyanotoxins, often without considering that some by-products and/or intermediates could be as harmful as the cyanotoxins [ 9 , 12 , 13 , 31 , 35 , 36 , 37 ].…”

“…By contrast, to quantify anatoxin-A, a Kinetex HILIC column measuring 100 mm by 2.1 mm i.d. for particles 2.6 μm in size (Phenomenex, Inc.; Basel, Switzerland) was employed for the stationary phase, while the mobile phase consisted of 95% ( v/v ) acetonitrile +5% ( v/v ) aqueous solution (i.e., 2 mM ammonium formate +3.6 mM formic acid) and an aqueous solution of 2 mM ammonium formate and 3.6 mM formic acid in a ratio of 85:15 [ 12 ]. The analysis was performed under equilibrium conditions, with a column temperature of 25 °C, a flow rate of 0.2 mL min −1 , and an injection volume of 20 μL.…”

“…In recent years, mounting evidence of increased cyanobacterial blooms and cyanotoxins worldwide has raised public awareness of their toxic effects on water use and water quality. Research has shown that the increased prevalence, occurrence, and abundance of cyanobacterial blooms, and, in turn, concentration of cyanotoxins in bodies of water on a global scale, are driven by eutrophication, rising concentrations of atmospheric CO 2 , and global warming, all of which stem from anthropogenic activities, especially climate change [ 2 , 9 , 11 , 12 ]. Because more frequent and prolonged blooms are likely to occur worldwide in the coming decades, the global context of the threat urges the development of simple, low-cost strategies and technologies for detoxicating and degrading cyanotoxins that can be readily implemented worldwide [ 2 , 9 ].…”

“…Of the various AOPs, heterogeneous photocatalysis, particularly when using TiO 2 -based photocatalysts, has emerged as an efficient approach to degrading, and eventually mineralizing, microcystins and cylindrospermopsin by using UV-light irradiation [ 9 , 12 , 13 ]. However, despite considerable efforts to improve TiO 2 ’s photocatalytic performance in mineralizing cyanotoxins under visible light or sunlight irradiation, usually via doping or surface modification, such laboratory-scale research has rarely assessed the integration of the photocatalysts into photocatalytic reactors [ 19 ].…”

Tin as an Effective Doping Agent into ZnO for the Improved Photodegradation of Rhodamine B

“…Rhodamine B (C 28 H 31 ClN 2 O 3 ) is amongst the dyes used in textile, food, and water tracing in order to track water for the determination of its treatment capabilities, food industry and textile choice for the wide range of researchers [29][30][31] where photo catalysts are used to remove the pollutants in the presence of light source. ZnO is playing dominating role as photo catalysts [32][33][34][35] while compared to other catalysts like [36][37] due to its low cost, higher absorption efficiency than titania, easy to grow, high stability in thermal, chemical and physical environments [38][39][40] and is utilized in wide range of applications. Moreover, as it is a direct wide band gap material having 3.37 eV of band gap it finds applications like in LEDs, laser diodes, photovoltaic, semiconductor heterojunction, transparent conductors, and so on [41][42][43][44].…”