Effect of crystalline structure on terbuthylazine degradation by H2O2-assisted TiO2 photocatalysis under visible irradiation

Ultrasound-assisted degradation of organophosphorus pesticide methidathion using CuFe2O4@SiO2-GOCOOH as a magnetic separable sonocatalyst

Water contamination by pesticides is a critical environmental issue, necessitating the development of sustainable and efficient degradation methods. This study focuses on synthesizing and evaluating a novel heterogeneous sonocatalyst for degrading pesticide methidathion. The catalyst consists of graphene oxide (GO) decorated CuFe₂O₄@SiO₂ nanocomposites. Comprehensive characterization using various techniques confirmed the superior sonocatalytic activity of the CuFe₂O₄@SiO₂-GOCOOH nanocomposite compared to CuFe₂O₄@SiO₂ alone. The enhanced performance is attributed to the combined effects of GO and CuFe₂O₄@SiO₂, including increased surface area, enhanced adsorption capabilities, and efficient electron transfer pathways. Reaction parameters such as time, temperature, concentration, and pH significantly influenced the degradation efficiency of methidathion. Longer reaction times, higher temperatures, and lower initial pesticide concentrations favored faster degradation and higher efficiency. Optimal pH conditions were identified to ensure effective degradation. Remarkably, the catalyst demonstrated excellent recyclability, indicating its potential for practical implementation in pesticide-contaminated wastewater treatment. This research contributes to the development of sustainable methods for environmental remediation, highlighting the promising potential of the graphene oxide decorated CuFe₂O₄@SiO₂ nanocomposite as an effective heterogeneous sonocatalyst for pesticide degradation.

Interaction Mechanisms and Application of Ozone Micro/Nanobubbles and Nanoparticles: A Review and Perspective

Ozone micro/nanobubbles with catalytic processes are widely used in the treatment of refractory organic wastewater. Micro/nanobubble technology overcomes the limitations of ozone mass transfer and ozone utilization in the application of ozone oxidation, and effectively improves the oxidation efficiency of ozone. The presence of micro/nanobubbles keeps the catalyst particles in a dynamic discrete state, which effectively increases the contact frequency between the catalyst and refractory organic matter and greatly improves the mineralization efficiency of refractory organic matter. This paper expounds on the characteristics and advantages of micro/nanobubble technology and summarizes the synergistic mechanism of microbubble nanoparticles and the mechanism of catalyst ozone micro/nanobubble systems in the treatment of refractory organics. An interaction mechanism of nanoparticles and ozone microbubbles is suggested, and the proposed theories on ozone microbubble systems are discussed with suggestions for future studies on systems of nanoparticles and ozone microbubbles.

Research Progress in Semiconductor Materials with Application in the Photocatalytic Reduction of CO2

The large-scale burning of non-renewable fossil fuels leads to the gradual increase of the CO2 concentration in the atmosphere, which is associated with negative impacts on the environment. The consequent need to reduce the emission of CO2 resulting from fossil fuel combustion has led to a serious energy crisis. Research reports indicate that the photocatalytic reduction of CO2 is one of the most effective methods to control CO2 pollution. Therefore, the development of novel high-efficiency semiconductor materials has become an important research field. Semiconductor materials need to have a structure with abundant catalytic sites, among other conditions, which is of great significance for the practical application of highly active catalysts for CO2 reduction. This review systematically describes various types of semiconductor materials, as well as adjustments to the physical, chemical and electronic characteristics of semiconductor catalysts to improve the performance of photocatalytic reduction of CO2. The principle of photocatalytic CO2 reduction is also provided in this review. The reaction types and conditions of photocatalytic CO2 reduction are further discussed. We believe that this review will provide a good basis and reference point for future design and development in this field.

Photocatalytic membranes: a new perspective for persistent organic pollutants removal

The presence of conventional and emerging pollutants infiltrating into our water bodies is a course of concern as they have seriously threatened water security. Established techniques such as photocatalysis and membrane technology have proven to be promising in removing various persistent organic pollutants (POP) from wastewaters. The emergence of hybrid photocatalytic membrane which incorporates both photocatalysis and membrane technology has shown greater potential in treating POP laden wastewater based on their synergistic effects. This article provides an in-depth review on the roles of both photocatalysis and membrane technology in hybrid photocatalytic membranes for the treatment of POP containing wastewaters. A concise introduction on POP's in terms of examples, their origins and their effect on a multitude of organisms are critically reviewed. The fundamentals of photocatalytic mechanism, current directions in photocatalyst design and their employment to treat POP's are also discussed. Finally, the challenges and future direction in this field are presented.

Impact of H2O2 on the Lactic and Formic Acid Degradation in Presence of TiO2 Rutile and Anatase Phases under UV and Visible Light

The degradation rates of formic acid and lactic acid in the presence and absence of H2O2 were studied, utilizing several TiO2 catalysts: PC105 (100% anatase), MPT 625 (100% rutile), and P25 (80% anatase/20% rutile), and the results were discussed with regards to the current literature. The impact of hydrogen peroxide on the photocatalytic efficiency of eleven TiO2 samples was then determined, using commercial anatase structures (PC105, PC500, UV100), commercial mixed anatase/rutile (P25 and P90), and six rutile (two commercial samples: MPT 625 and C-R160, and four home-made rutile samples were synthesized by TiCl4 hydrolysis). The effect of catalyst surface area and TiO2 phase on the degradation rate of lactic acid (LA) and the decomposition of H2O2 was studied and discussed in regard to the active species generated. The intermediate products formed in the absence and presence of H2O2 were also an important factor in the comparison. Finally, the efficiency of the degradation of LA and formic acid (FA) in the presence of rutile and H2O2 was determined under visible light, and their reactivity was compared. The intermediate products formed in the degradation of LA were identified and quantified and compared to those obtained under UV (Ultra-Violet).