Review on heterogeneous photocatalytic disinfection of waterborne, airborne, and foodborne viruses: Can we win against pathogenic viruses?

Progress of zinc oxide-based nanocomposites in the textile industry

The levels of pesticides in water have increased due to their excessive use in the modern agricultural domain Choosing a suitable water treatment method for pesticide removal depends on the type of pesticide and the efficacy of the treatment process This review critically discusses and provides a detailed description of a variety of chemical, physical, and biological approaches for pesticide removal from water, such as advanced oxidation processes, adsorption, activated sludge, membrane bioreactors, and membrane technologies Both single-treatment and hybrid methods are thoroughly described and critically discussed The use of hybrid removal techniques offers potential opportunities to develop innovative pesticide removal techniques A thorough analysis of influent composition and recognition of the best removal technique is very important to design a water treatment plant that targets the maximum possible removal rate for different types of pesticides Furthermore, the decentralization of water treatment was also discussed in which it is an important approach that would lead to better effluent water quality for lower prices Many affordable techniques such as activated sludge and adsorption by agricultural adsorbents showed high efficacy in treating high levels of different pesticides

Removal of pesticides from water and wastewater: Chemical, physical and biological treatment approaches

Along with the development of industry and the improvement of people’s living standards, peoples’ demand on resources has greatly increased, causing energy crises and environmental pollution. In recent years, photocatalytic technology has shown great potential as a low-cost, environmentally-friendly, and sustainable technology, and it has become a hot research topic. However, current photocatalytic technology cannot meet industrial requirements. The biggest challenge in the industrialization of photocatalyst technology is the development of an ideal photocatalyst, which should possess four features, including a high photocatalytic efficiency, a large specific surface area, a full utilization of sunlight, and recyclability. In this review, starting from the photocatalytic reaction mechanism and the preparation of the photocatalyst, we review the classification of current photocatalysts and the methods for improving photocatalytic performance; we also further discuss the potential industrial usage of photocatalytic technology. This review also aims to provide basic and comprehensive information on the industrialization of photocatalysis technology.

https://www.mdpi.com/2076-3417/9/12/2489/pdf

Recent Advances and Applications of Semiconductor Photocatalytic Technology

Zinc oxide (ZnO) is a multifunctional material due to its exceptional physicochemical properties and broad usefulness. The special properties resulting from the reduction of the material size from the macro scale to the nano scale has made the application of ZnO nanomaterials (ZnO NMs) more popular in numerous consumer products. In recent years, particular attention has been drawn to the development of various methods of ZnO NMs synthesis, which above all meet the requirements of the green chemistry approach. The application of the microwave heating technology when obtaining ZnO NMs enables the development of new methods of syntheses, which are characterised by, among others, the possibility to control the properties, repeatability, reproducibility, short synthesis duration, low price, purity, and fulfilment of the eco-friendly approach criterion. The dynamic development of materials engineering is the reason why it is necessary to obtain ZnO NMs with strictly defined properties. The present review aims to discuss the state of the art regarding the microwave synthesis of undoped and doped ZnO NMs. The first part of the review presents the properties of ZnO and new applications of ZnO NMs. Subsequently, the properties of microwave heating are discussed and compared with conventional heating and areas of application are presented. The final part of the paper presents reactants, parameters of processes, and the morphology of products, with a division of the microwave synthesis of ZnO NMs into three primary groups, namely hydrothermal, solvothermal, and hybrid methods.

A Review of Microwave Synthesis of Zinc Oxide Nanomaterials: Reactants, Process Parameters and Morphologies

In the past few decades, many novel non-metal doped ZnO materials have developed hasty interest due to their adaptable properties such as low recombination rate and high activity under the solar light exposure. In this article, we compiled recent research advances in non-metal (S, N, C) doped ZnO, emphasizing on the related mechanism of catalysis and the effect of non-metals on structural, morphological, optical and photocatalytic characteristics of ZnO. This review will enhance the knowledge about the advancement in ZnO and will help in synthesizing new ZnO-based materials with modified structural and photocatalytic properties.

S-, N- and C-doped ZnO as semiconductor photocatalysts: A review

TiO2 is a well-known material and has remarkable physical, chemical and biocompatible properties which have made it a suitable material in the biological world. The development of new TiO2-based materials is strongly required to achieve desired properties and applications. A large number of TiO2 composites have been synthesized and applied in various fields. The present review reports the utility of TiO2 and its composites in biosensing, in Photodynamic Therapy, as an antimicrobial agent and as a nanodrug carrier. The aim of this review is to discuss the biological application of the TiO2 based materials and some recent advancement in TiO2 to enhance its application in the biological world.

TiO2 and its composites as promising biomaterials: a review.

Advanced oxidation process (AOP) is a versatile photocatalytic approach to degrade various environmental pollutants. Among many photocatalysts used in AOP such as ZnO, TiO2, ZrO2, ZnS, CdS; TiO2 is the most widely adopted semiconductor material. TiO2 is a wide band gap material and absorb in UV spectrum which is a narrow region in the sun light. This benchmark makes it a less efficient photocatalyst under sunlight irradiation. To enhance the photocatalytic efficiency, the absorption band of photocatalyst should be modified in such a way that it leads to maximum absorption in the solar spectrum. The doping of nonmetals such as N, C, P and S etc. shift the band edge of the semiconductors towards the visible region and thus increases the photon absorption which successively enhances the photocatalytic efficiency. In this review, we have focused on effect of nonmetal doping on the properties and photocatalytic activity of the TiO2. Influence of various aspects such as synthesis procedure, doping source, concentration of dopant, calcination etc. are also explored towards alteration in properties and photocatalytic efficiency of nonmetals doped TiO2.

Non-metal modified TiO2: a step towards visible light photocatalysis

A series of coupled ZnO-SnO2 photocatalyst was successfully synthesized in the Zn:Sn molar ratio of 20:1, 10:1, 5:1 and 2:1 via co-precipitation method followed by calcination at different temperatures. The synthesized materials were characterized by X-ray diffraction, diffuse reflectance spectra, scanning electron microscope and transmission electron microscope. Photocatalytic activitiy of synthesized materials was applied for the degradation of cibacron red dye in aqueous solution under UV-A light irradiation. Experimental results revealed that the coupled ZnO-SnO2 photocatalyst with Zn:Sn molar ratio 10:1, calcined at 600oC for 1 h was the most efficient photocatalyst among synthesized samples for the degradation of cibacron red. Superoxide anion radical (•O2–) was found to be the prominent active species responsible for degradation comparative to hole (h+), hydroxyl radical (•OH).

Synthesis and Charcterization of Coupled ZnO/SnO2 Photocatalysts and Their Activity towards Degradation of Cibacron Red Dye

Nano Titania is the promising material for the photocatalytic process used in the minimization of the organic pollutant. However, there is need to enhance its absorption and surface properties to design a material having high efficacy. In this study, we report the synthesis of binary and ternary TiO2 nano-composites using the CdS and ZnS nanoparticles by adopting the low temperature two-step hydrothermal approach. The synthesized materials were characterized by using XRD, UV-DRS, FESEM, HRTEM, XPS and BET surface area analyzer. The photocatalytic activity was evaluated by taking the Rhodamine B (RhB) as model pollutant by employing an ultra low LED photo reactor. It was found that, the ternary TiO2/CdS/ZnS composite containing 10% ZnS and 20% CdS in wt. ratio showed the best activity towards the removal of RhB. The enhanced activity was due to improvement in the absorbance in the visible region and formation of heterojunction, which enhanced the lifetime of photoinduced charged species by the reduction in charge recombination. Reactive species, prominently responsible for degradation was identified by the scavenger action. The degradation pathway by which the RhB degraded is also discussed and found that degradation pathway altered with pH of solution.

Anuj Mittal

Papers

S-, N- and C-doped ZnO as semiconductor photocatalysts: A review

TiO2 and its composites as promising biomaterials: a review.

Non-metal modified TiO2: a step towards visible light photocatalysis

Synthesis and Charcterization of Coupled ZnO/SnO2 Photocatalysts and Their Activity towards Degradation of Cibacron Red Dye

Highly efficient, visible active TiO2/CdS/ZnS photocatalyst, study of activity in an ultra low energy consumption LED based photo reactor