Interfacial phenomena during Fenton reaction on starch stabilized magnetite nanoparticles: Molecular dynamics and experimental investigations

Polymer-Supported Heterogeneous Fenton Catalysts for the Environmental Remediation of Wastewater

Materials based on polymer hydrogels have demonstrated potential as innovative Fenton catalysts for treating water. However, developing these polymer-supported catalysts with robust stability presents a significant challenge. This paper explores the development and application of polymer-supported heterogeneous Fenton catalysts for the environmental remediation of wastewater, emphasizing the enhancement of metal incorporation into catalysts for improved efficiency. The study begins with an introduction to the heterogeneous Fenton process and its relevance to wastewater treatment. It further delves into the specifics of polymer-supported heterogeneous Fenton catalysts, focusing on iron oxide, copper complexes/nanoparticles, and ruthenium as key components. The synthesis methods employed to prepare these catalysts are discussed, highlighting the innovative approaches to achieve substantial metal incorporation. Operational parameters such as catalyst dosage, pollutant concentration, and the effect of pH on the process efficiency are thoroughly examined. The catalytic performance is evaluated, providing insights into the effectiveness of these catalysts in degrading pollutants. Recent developments in the field are reviewed, showcasing advancements in catalyst design and application. The study also addresses the stability and reusability of polymer-supported heterogeneous Fenton catalysts, critical factors for their practical application in environmental remediation. Environmental applications are explored, demonstrating the potential of these catalysts in addressing various pollutants. The Conclusions offers future perspectives, underlining the ongoing challenges and opportunities in the field, and the importance of further research to enhance the efficacy and sustainability of polymer-supported heterogeneous Fenton catalysts for wastewater treatment.

Mechanism of phenol and p-nitrophenol adsorption on kaolinite surface in aqueous medium: A molecular dynamics study

Very few aqueous medium experimental studies focus on the molecular interaction mechanism between the adsorbent and the adsorbate. Herein, we investigate the adsorption of two organic pollutants, phenol and p-nitrophenol (PNP) in dilute aqueous solution conditions on kaolinite (001) surface through classical molecular dynamics (MD) simulations. The present investigation addresses both adsorption isotherms and mechanistic issues. MD simulations at different solute concentrations generated density profiles and, thereby, adsorption isotherms. The data generated for phenol adsorption fitted both Langmuir and Freundlich isotherm models equally well. Alternatively, PNP adsorption data on the kaolinite surface followed the Langmuir model better. Overall, phenol exhibits a higher adsorption capacity on kaolinite than PNP. These results support the experimental observations made in earlier publications in the literature. Radial distribution functions (RDF) between various atom types on the adsorbent and molecules in the solution phase point toward hydrogen bond-dominated interaction mechanisms for organic pollutants.

AgI/CuWO4 Z-scheme photocatalyst for the degradation of organic pollutants: Experimental and molecular dynamics studies

While the knowledge of the adsorption properties of components of a composite heterogeneous photocatalyst is critical to its applicability to a particular reaction, there has been little research in this direction. The present research is on the development of AgI/CuWO₄ nanocomposites that photocatalytically degraded ciprofloxacin and rhodamine B in an aqueous medium under visible light irradiation. The nanocomposites were prepared by a step-wise precipitation protocol. XPS analysis and active species trapping experiments demonstrated that the photocatalysis proceeded by a Z-scheme mechanism. Large scale aqueous medium molecular dynamics simulations showed that oxygen and CIP adsorb on the AgI part, while water interacts intensely with the CuWO₄ component. Information from experimental and molecular dynamics studies was combined to arrive at the photocatalysis mechanism.