Antibacterial Activity of Solvothermal Obtained ZnO Nanoparticles with Different Morphology and Photocatalytic Activity against a Dye Mixture: Methylene Blue, Rhodamine B and Methyl Orange

Abstract

In this paper, we report the synthesis of ZnO nanoparticles (NPs) by forced solvolysis of Zn(CH3COO)2·2H2O in alcohols with a different number of –OH groups. We study the influence of alcohol type (n-butanol, ethylene glycol and glycerin) on the size, morphology, and properties of the obtained ZnO NPs. The smallest polyhedral ZnO NPs (<30 nm) were obtained in n-butanol, while in ethylene glycol the NPs measured on average 44 nm and were rounded. Polycrystalline particles of 120 nm were obtained in glycerin only after water refluxing. In addition, here, we report the photocatalytic activity, against a dye mixture, of three model pollutants: methyl orange (MO), methylene blue (MB), and rhodamine B (RhB), a model closer to real situations where water is polluted with many chemicals. All samples exhibited good photocatalytic activity against the dye mixture, with degradation efficiency reaching 99.99%. The sample with smallest nanoparticles maintained a high efficiency >90%, over five catalytic cycles. Antibacterial tests were conducted against Gram-negative strains Salmonella enterica serovar Typhimurium, Pseudomonas aeruginosa, and Escherichia coli, and Gram-positive strains Enterococcus faecalis, Bacillus subtilis, Staphylococcus aureus, and Bacillus cereus. The ZnO samples presented strong inhibition of planktonic growth for all tested strains, indicating that they can be used for antibacterial applications, such as water purification.

Theoretical and Experimental Study of the Photocatalytic Properties of ZnO Semiconductor Nanoparticles Synthesized by Prosopis laevigata

“…On the other hand, the speed of the photocatalytic reaction of the nanoparticles was 0.0305, 0.0387, and 0.0771 for the ZnO_PL1%, ZnO_PL2%, and ZnO_PL4% samples, respectively. Similar values have been found in the literature, for example, the work of Ludmila Motelica et al in 2022 where they synthesized ZnO nanoparticles using various alcohols, reporting reaction rates of the nanoparticles between 0.0569 and 0.0935 [52]. In the present study, the ZnO_PL4% sample was the one that reached a higher reaction rate, which is attributed to the percentage of extract used in the biosynthesis.…”

“…In addition, the smaller the size of the nanoparticles, the greater the number of defects on the nanoparticle surface because there is a greater surface area. These defects represent catalytic centers for the photodegradation of polluting molecules, leading to improved photocatalytic activity [40,52,53]. In order to study the effect of mass transfer resistance of the dye to the catalytic surface, a variation in the amount of MB was made with the largest nanoparticles (1%), which is important for the control of the pressure drop in the design of packed bed reactors.…”

Control Synthesis of Metallic Gold Decorated ZnO Nanoparticles for Photocatalytic Degradation of Rhodamine B, Methylene Blue and Eriochrome Black T Dyes

“…The d‐level of Au reduce the band gap energy and extends the absorption to the visible region. This reduction in gap energy increases the photocatalytic performance [41] …”

Single step facile synthesis of Cu-SnO2/ZnO nanocomposite photocatalyst for methylene blue dye degradation in aqueous solution

“…Similarly, a strong stretching peak observed at 2340 cm −1 assigned to CO 2 (O=C=O) was introduced from the ambient environment [20]. The absorption peak of ZnO, SnO 2 /ZnO, and Cu-SnO 2 /ZnO nanocomposites at 908 cm −1 , 906 cm −1 , and 916 cm −1 corresponds to tetrahedral Zn 2+ ion, respectively [28]. In Cu-SnO 2 nanoparticles, the absorptions observed at the wavenumber of 1741 cm −1 , 1367 cm −1 and 1220 cm −1 due to C=O, C−O and C−OH stretching, respectively [29] The O−Sn−O stretching vibrations were detected at Table 1.…”