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Photocatalytic Inactivation of Pathogenic Viruses Using Metal Oxide and Carbon-Based Nanoparticles
Published in Devarajan Thangadurai, Saher Islam, Charles Oluwaseun Adetunji, Viral and Antiviral Nanomaterials, 2022
Lan Ching Sim, Wei Qing Wee, Shien Yoong Siow, Kah Hon Leong, Jit Jang Ng, Pichiah Saravanan
The use of a photocatalyst is environmental-friendly and sustainable because of the employment of renewable energy as the energy source of the photocatalytic viral inactivation. This chapter provides a review on the development of photocatalytic inactivation of viruses using metal oxide NPs and carbon-based NPs. Despite recent advances, some potential research is yet to be explored to overcome new challenges provoked by viral pandemic cases. Future work should explore the coating of photocatalysts on face masks or other surfaces to control the viral spread of Coronavirus 2 (SARS-CoV-2) via fomite and aerosol. Further, molecular imprinting could be used to selectively adsorb viruses and concentrate them near photocatalytic sites for inactivation. It has been proven to be effective in waterborne viral inactivation. There is lack of investigation on the viral inactivation mechanism using a combination of quantitative analytical tools since the foremost discovery by Wigginton et al. (2012). This approach helps to identify and quantify the extent of modifications in the virus genome or proteins by measuring the damage at well-defined levels of inactivation (Wigginton et al. 2012). Most of the viral inactivation methods are reported by using UVC light at 254 nm, which is harmful to skin and eyes. Hence, it is suggested to use far-UVC light (207–222 nm) or visible light (390–750 nm) to reduce the negative effects of UVC light. And for that, it will be necessary to develop a photocatalyst material that could harvest more visible light.
Green-Synthesized Nanoparticles as Potential Sensors for Health Hazardous Compounds
Published in Richard L. K. Glover, Daniel Nyanganyura, Rofhiwa Bridget Mulaudzi, Maluta Steven Mufamadi, Green Synthesis in Nanomedicine and Human Health, 2021
Rachel Fanelwa Ajayi, Sphamandla Nqunqa, Yonela Mgwili, Siphokazi Tshoko, Nokwanda Ngema, Germana Lyimo, Tessia Rakgotho, Ndzumbululo Ndou, Razia Adam
Photocatalysis synthesis methods play a significant role in green processes since it provides an alternative to classical chemistry. It offers suitable tools for industrial reactions using cells and enzymes, which can be carried out under mild conditions, with a great control over chemo-, regio- and stereoselectivity by using appropriate enzymes and with the use of heavy metals (Hernaiz et al., 2010). Additionally, in fine chemistry, the activation by photocatalysis under visible light could be another method. This innovative approach is very attractive due to circumvents of the use of heavy metals. In this method, light can be considered as an ideal reagent which is environmentally friendly in green chemical synthesis. These days, the advancement of photo-redox catalysis originated from visible light is of real significance. The reaction of this method is usually carried out by photo-redox catalysts and organometallic complexes containing iridium and ruthenium (Grewal et al., 2013).
Interactions between Oral Bacteria and Antibacterial Polymer-Based Restorative Materials
Published in Mary Anne S. Melo, Designing Bioactive Polymeric Materials for Restorative Dentistry, 2020
Fernando L. Esteban Florez, Sharukh S. Khajotia
Cai et al.[202] investigated the influence of UV-driven photocatalysis on the surface roughness, hydrophobicity, morphology, cytotoxicity, bacteria and fibroblast cell adhesion, and bioactivity (ability to form hydroxyapatite) properties of an experimental dental adhesive resin containing Bis-GMA and HEMA (55/45 wt/wt ratio) and nTiO2 (20 wt%, P25, Evonik Industries, AG Germany). In their study, specimens fabricated with experimental materials were light-irradiated (1, 3, and 12 h) either in water or in air. The results reported have demonstrated that experimental materials were significantly impacted (both positively and negatively) by U.V. photocatalysis. Concerning their surface properties (wettability and morphology), it becomes clear that the use of U.V. wavelengths resulted in surfaces that were significantly more hydrophilic and rougher when compared to control group samples (nTiO2-free). It can be hypothesized from the results reported that UV-driven surface degradation might result in restorative materials that are more susceptible to bacterial accumulation and biodegradation. With regard to cell adhesion (both bacteria and dermal fibroblasts), antibacterial activity, and bioactivity, the results have shown that experimental materials were less cytotoxic, more antibacterial, and capable of promoting the formation of significant amounts of hydroxyapatite on the surface of experimental nTiO2-containing materials.
Cerium oxide thin films: synthesis, characterization, photocatalytic activity and influence on microbial growth
Published in Biofouling, 2022
Luminita Andronic, Damir Mamedov, Cristina Cazan, Marcela Popa, Mariana Carmen Chifiriuc, Atabek Allaniyazov, Simona Palencsar, Smagul Zh. Karazhanov
Photocatalysis is an emerging technology for wastewater treatment that can function under the influence of sunlight in the presence of catalyst material. The free electrons and holes that generated in the catalyst under the influence of sunlight, UV lamps, xenon lamps, etc., migrate to form oxidising species such as hydroxyl (⋅OH) or superoxide (O2-) radicals that exhibit strong oxidation of pollutants leading to their degradation (Rueda-Marquez et al. 2020). Semiconductors are materials that possess both light-absorbing and catalytic properties. Although many narrow bandgap materials such as Si, CdS, CdSe possess advanced sunlight absorbing properties, they are electrochemically unstable. On the other hand, wide-bandgap metal oxides such as TiO2, ZnO, WO3, V2O5, etc., are stable, low cost, abundant, and non-toxic, but they absorb only UV light.
Colloidal synthesis of biocompatible iron disulphide nanocrystals
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
J. Santos-Cruz, R. E. Nuñez-Anita, S. A. Mayén-Hernández, O. Martínez-Alvarez, L. S. Acosta-Torres, J. de la Fuente-Hernández, E. Campos-González, M. Vega-González, M. C. Arenas-Arrocena
Photocatalysis improved most in the synthesis at a temperature of 225 °C, then for the synthesis at 240 °C and least for the synthesis at 235 °C. This could be the result of the obtained phases and particle sizes (which increased as a function of temperature). The three temperatures showed a range of phases between pyrite (FeS2) and pyrrhotite (Fe1-XS, where X = 0–0.2). The phases only varied in the amount of iron present in the formula. The synthesis at 240 °C showed a mixture of phases between pyrite and pyrrhotite, while synthesis at 235 °C showed a mixture of pyrite and pyrrhotite with a considerable amount of pyrite. Finally, the synthesis at 225 °C showed a greater amount of pyrrhotite. It is well known that the pyrrhotite phase is less stable than pyrite; it reacts quicker to Fe2+ ions than in the presence of oxygen from water. The Fe2+ ion oxidizes to Fe3+, causing greater formations of reactive species in the form of hydroxyl radical. A hydroxyl radical is strongly oxidizing when derived from hydrogen peroxide [22,32–35]. This is known as Fenton's process, which is an advanced oxidation process resulting from the following reaction:
The effective photocatalysis and antibacterial properties of AgBr/Ag2MoO4@ZnO composites under visible light irradiation
Published in Biofouling, 2019
Huihui Xu, Jie Zhang, Xianzi Lv, Tianjie Niu, Yuxiang Zeng, Jizhou Duan, Baorong Hou
Recently, Ag2MoO4 has attracted extensive attention because of its controllable morphology and wide applications in the fields of photoluminescence, conducting glasses and antibacterial materials. Some scientists have designed Ag2MoO4-based composites to improve the photocatalytic performance, such as Bi2MoO6@Ag2MoO4 (Wang et al. 2017), Ag2MoO4/Ag3PO4 (Huo et al. 2018), and g-C3N4/Ag2MoO4 (Wu et al. 2018; Liu et al. 2018; Xie et al. 2018). The degradation rates of rhodamine B (RhB) solution by the photocatalysis of these composites were 90%, 81.5% and 95%, respectively, which were higher than the degradation rate (19.1%) of RhB by the photocatalysis of pure Ag2MoO4. At the same time, AgBr has been widely investigated as a co-catalyst of Ag-based semiconductors because of its narrow band gap, simple preparation, and excellent photocatalytic activity. Similar research for Ag@AgBr-Ag2Mo3O10 (Liu et al. 2018), g-C3N4/AgBr/rGO (Zhou et al. 2018), Ag@AgBr/CaTiO3 (Bai et al. 2018), and Ag@AgBr/BiVO4 (Cai et al. 2018) also demonstrate that AgBr is extremely adaptable for the preparation of highly effective and stable photocatalysts. The catalysts mentioned above are seldom used to degrade antibiotics and sterilize bacteria. Therefore, there is an urgent need to develop a new environmentally friendly photocatalyst that can be used for both antibacterial and degradation of antibiotics.