Advancing nanoarchitectures of 2D WO3/MXene photoanode for enhanced photoelectrocatalytic oxidation of phenol and arsenic in synthetic wastewater.

The photoelectrocatalytic advanced oxidation process (PEAOP) necessitates high-performing and stable photoanodes for the effective oxidation of complex pollutants in industrial wastewater. This study presents the construction of 2D WO3/MXene heteronanostructures for the development of efficient and stable photoanode. The WO3/MXene heterostructure features well-ordered WO3 photoactive sites anchored on micron-sized MXene sheets, providing an increased visible light active catalytic surface area and enhanced electrocatalytic activities for pollutant oxidation. Phenol, a highly toxic compound, was completely oxidized at an applied potential of 0.8 V vs. RHE under visible light irradiation. Systematic optimization of operational conditions for the photoelectrocatalytic oxidation of phenol was conducted. The phenol oxidation mechanism was elucidated via high-performance liquid chromatography (HPLC) analysis and the identification of intermediate compounds. Additionally, a mixed model of phenol and arsenic (III) in polluted water demonstrated the capability of WO3/MXene photoanode for the simultaneous oxidation of both organic and inorganic pollutants, achieving complete conversion of phenol and As(III) to non-toxic As(V). The WO3/MXene photoanode facilitated water oxidation, generating a substantial amount of O2•- and •OH oxidative species, which are crucial for the concurrent oxidation of phenol and arsenic. Recyclability tests demonstrated a 99% retention of performance, confirming the WO3/MXene photoanode's suitability for long-term operation in PEAOPs. The findings suggest that integrating WO3/MXene photoanodes into water purification systems can enhance economic feasibility, reduce energy consumption, and improve efficiency. This PEAOP offers a viable solution to the critical issue of heavy metal and organic chemical pollution in various water bodies, given its scalability and ability to preserve ecosystems while conserving clean water resources.

Sustainable photoelectrocatalytic oxidation of antibiotics using Ag-CoFe2O4@TiO2 heteronanostructures for eco-friendly wastewater remediation.

Developing high-performance and durable catalysts presents a significant challenge for oxidizing toxic inorganic and pharmaceutical compounds in wastewater. Recently, there has been a surge in the development of new heterogeneous catalysts for degrading pharmaceutical compounds, driven by advancements in electrocatalysts and photoelectrocatalysts. In this study, a plasmonic Ag nanoparticles decorated CoFe2O4@TiO2 heteronanostructures have been successfully designed to fabricate a high-performing photoelectrode for the oxidation of pharmaceutical compounds. The developed Ag-CoFe2O4@TiO2 possessed a higher electrochemical stability and effectively harvested the UV to visible and NIR radiation in sunlight which generates the enormous photochemical reactive species that involved in the oxidation of ibuprofen in wastewater. Under direct sunlight irradiation, Ag-CoFe2O4@TiO2 achieved complete oxidation of ibuprofen in wastewater at 0.8 V vs RHE. This indicates that metallic Ag nanoparticles are involved in the charge separation and transport of charge carriers from the photoactive sites of CoFe2O4@TiO2, promoting the generation of abundant hydroxy, oxy, and superoxide radicals that actively break the bonds of ibuprofen. Additionally, oxidation agents such as urea and H2O2 were utilized to enhance the formation of superoxide ions and hydroxyl radicals, which rapidly participate in the oxidation of ibuprofen. Significantly, testing for recyclability confirmed the stability of the Ag-CoFe2O4@TiO2 photoanode, ensuring its suitability for prolonged use in photoelectrochemical advanced oxidation processes. Integrating Ag-CoFe2O4@TiO2 photoanodes into water purification systems could enhance economic feasibility, reduce energy consumption, and improve efficiency.