Boosted electrocatalytic oxidation of organophosphorus pesticides by a novel high-efficiency CeO2-Doped PbO2 anode: An electrochemical study, parameter optimization and degradation mechanisms

Electrochemical degradation of toluene-2,4-diamine by graphene oxide-modified Ti/Sb-SnO2/α-PbO2/β-PbO2 anode: Performance and mechanism

The formidable toluene-2,4-diamine (TDA), a potential human carcinogenic pollutant, environmental challenge necessitates investigating an efficient technology and clarifying its removal mechanism. Accordingly, we prepared a graphene oxide-modified PbO2 anode (Ti/Sb-SnO2/α-PbO2/GO-β-PbO2) to degrade TDA using electrochemical oxidation technology given its high oxidation capacity and green feature. The Ti/Sb-SnO2/α-PbO2/GO-β-PbO2 attained 100 % TDA and 82.7 % COD removal efficiency after 3.0 h electrolysis for its high oxygen evolution overpotential (2.08 V vs.SCE), superior ⋅OH generation capacity, and hydrophobic surface (121.2°). The quenching experiments and EPR tests all confirmed the vital role of both ⋅OH and SO4·-, resulting in the oxidation of the benzene ring and amino group. Moreover, the (Ti/Sb-SnO2/α-PbO2/GO-β-PbO2 also presented an improved stability with the accelerated lifetime prolonged by about 50.8 %. Therefore, this work provides a toolbox for treating TDA wastewater and a good reference for fabricating PbO2 anode via a facile yet effective method.

A comprehensive review of PbO2 electrodes in electrocatalytic degradation of organic pollutants

This paper provides a systematic review of recent advancements in PbO2 electrodes for the electrocatalytic degradation of organic pollutants, emphasizing innovative breakthroughs and key technological optimizations in this domain. This work analyzes PbO2 electrode fabrication methods, assessing strengths/weaknesses, and summarizes recent advances in surface modification. Atomic-scale strategies such as elemental doping, composite oxides, and nanomaterial coupling, enhance its catalytic performance. Kinetic modeling and characterization confirm the improved efficiency and durability in organic contaminant mineralization. Kinetic and experimental analyses demonstrate the high efficiency and stability of modified PbO2 electrodes in degrading organic pollutants. Industrial feasibility analysis indicates that the PbO2 electrode demonstrates technical robustness, economic viability, and scalability for industrial implementation. This work elucidates direct/indirect oxidation mechanisms in electrocatalysis, revealing correlations between surface reactive sites and active oxidant generation, guiding electrode design optimization. Looking ahead, this paper proposes innovative trajectories for PbO2 electrode technology, such as exploring novel modified materials, intelligently designing hierarchical architectures, and integrating advanced systems with smart control. These directions aim to promote its widespread use in environmental protection for more efficient and eco-friendly organic pollutant treatment. This review enriches the theoretical framework for PbO2 electrode electrocatalytic degradation of organic contaminants and offers references and inspirations for future research.

Co-Activating Lattice Oxygen of TiO2-NT and SnO2 Nanoparticles on Superhydrophilic Graphite Felt for Boosting Electrocatalytic Oxidation of Glyphosate

Glyphosate (GH) wastewater potentially poses hazards to human health and the aquatic environment, due to its persistence and toxicity. A highly superhydrophilic and stable graphite felt (GF)/polydopamine (PDA)/titanium dioxide nanotubes (TiO2-NT)/SnO2/Ru anode was fabricated and characterized for the degradation of glyphosate wastewater. Compared to control anodes, the GF/PDA/TiO2-NT/SnO2/Ru anode exhibited the highest removal efficiency (near to 100%) and a yield of phosphate ions of 76.51%, with the lowest energy consumption (0.088 Wh/L) for degrading 0.59 mM glyphosate (GH) at 7 mA/cm2 in 30 min. The exceptional activity of the anode may be attributed to the co-activation of lattice oxygen in TiO2-NT and SnO2 by coupled Ru, resulting in a significant amount of •O2- and oxygen vacancies as active sites for glyphosate degradation. After electrolysis, small molecular acids and inorganic ions were obtained, with hydroxylation and dephosphorization as the main degradation pathways. Eight cycles of experiments confirmed that Ru doping prominently enhanced the stability of the GF/PDA/TiO2-NT/SnO2/Ru anode due to its high oxygenophilicity and electron-rich ability, which promoted the generation and utilization efficiency of active free radicals and defects-associated oxygen. Therefore, this study introduces an effective strategy for efficiently co-activating lattice oxygen in SnO2 and TiO2-NT on graphite felt to eliminate persistent organophosphorus pesticides.

Light harvesting enhancement through band structure engineering in graphite carbon nitride / polydopamine nanocomposite photocatalyst: Addressing persistent organophosphorus pesticide pollution in water systems

Organophosphorus pesticides, particularly profenofos (PF), pose a significant threat to the food supply and human health due to their persistence, toxicity, and resistance to natural breakdown processes. An urgent need exists for an environmentally friendly solution, and photocatalysis emerges as a practical, cost-effective option. However, challenges like poor light responsiveness and difficulties in material separation and reusability persist. To address these issues, we developed a nanocomposite consisting of graphite carbon nitride (g-C3N4) doped with polydopamine (pDA) through a hydrothermal synthesis method. This innovative nanocomposite was employed as a photocatalyst to degrade PF. Various analytical techniques, including UV-DRS, FT-IR, XRD, HR-TEM, and EDAX, were utilized to characterize the synthesized nanocomposite. The strategically modulated band gaps of the nanocomposite enable efficient absorption of UV light, facilitating the robust photocatalytic degradation of PF (96.4%). Our study explored photodegradation using different g-C3N4/pDA catalyst dosages, varied PF concentrations, and pH levels (3, 5, 9, and 11) under UV light. Our findings promise applications in wastewater management, offering an efficient catalyst for PF degradation. This marks a significant stride in addressing challenges related to pesticide pollution in the environment.