Immobilization of MIL-88(Fe) anchored TiO2-chitosan(2D/2D) hybrid nanocomposite for the degradation of organophosphate pesticide: Characterization, mechanism and degradation intermediates

• Published in: Journal of hazardous materials Vol. 406; p. 124728
• Main Authors: Vigneshwaran, Sivakumar, Sirajudheen, Palliyalil, Karthikeyan, Perumal, Nikitha, Manuvelraja, Ramkumar, Krishnapillai, Meenakshi, Sankaran
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.03.2021
• Subjects: 2D/2D hybrid photocatalyst; carbon dioxide; catalytic activity; Degradation pathway; irradiation; light; MCP; Mineralization; monocrotophos; nanocomposites; nanosheets; oxidation; photocatalysts; pollutants; soil; TCS@MOF; TCS@MOF; 2D/2D hybrid photocatalyst; MCP; Mineralization; Degradation pathway
• ISSN: 0304-3894; 1873-3336; 1873-3336
• DOI: 10.1016/j.jhazmat.2020.124728

In this study, we have rationally designed and grafted a bio-assisted 2D/2D TiO2/MIL-88(Fe) (TCS@MOF) heterojunction by growing granular TiO2 on the surface of MIL-88(Fe) nanosheet, as hybrid photocatalyst. The hierarchical TCS@MOF composite was prepared via the one-pot solvothermal process and employed for monocrotophos (MCP) degradation under visible light region, since its persistent nature on soil and water causes major threat to the environment. The TCS@MOF promotes a number of packed high-speed nano-tunnels in the (p-n) heterojunctions, which significantly enhance the migration of photo-induced electrons (e−) and holes (h+), respectively and thus limits the charge recombination of e−s. The optimized photocatalyst achieves significant catalytic activity of ~98.79% for the degradation of MCP within 30 min of irradiation. The prominent oxidative radicals namely •OH, •O2− etc., were involved in the oxidation of organic pesticide. Besides, TCS@MOF exhibits outstanding stability even after five repetitive cycles for the oxidation of MCP with a negligible decrease in photo-activity. The proposed mechanism and oxidative pathways of MCP were rationally deduced in detail subject to experimental results. The mechanism renders insight into the oxidation and consequent bond rupture of pollutant as well as into the formation of products such as H2O, CO2, etc. This report unveils a novel architecture of proficiently optimized TCS@MOF material structure for the perceptive oxidation of organic contaminants. [Display omitted] ●A rational TCS@MOF was fabricated through solvothermal method.●TCS@MOF was used to degrade MCP via visible light irradiation.●Investigation of various influencing parameters and batch studies were carried out.●TCS@MOF exhibited excellent photo-stability over five regeneration cycles.●A possible mechanism for MCP degradation by the photocatalyst was proposed.