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

Sivakumar Vigneshwaran; Palliyalil Sirajudheen; Perumal Karthikeyan; Manuvelraja Nikitha; Krishnapillai Ramkumar; Sankaran Meenakshi

doi:10.1016/j.jhazmat.2020.124728

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

J Hazard Mater. 2021 Mar 15:406:124728. doi: 10.1016/j.jhazmat.2020.124728. Epub 2020 Dec 2.

Authors

Sivakumar Vigneshwaran¹, Palliyalil Sirajudheen², Perumal Karthikeyan³, Manuvelraja Nikitha⁴, Krishnapillai Ramkumar⁵, Sankaran Meenakshi⁶

Affiliations

¹ Department of Chemistry, The Gandhigram Rural Institute - Deemed to be University, Gandhigram 624302, Dindigul, Tamil Nadu, India. Electronic address: vigneshwarangri@gmail.com.
² Department of Chemistry, The Gandhigram Rural Institute - Deemed to be University, Gandhigram 624302, Dindigul, Tamil Nadu, India; Department of Chemistry, Pocker Sahib Memorial Orphanage College, Tirurangadi, 676306, Malappuram, Kerala, India. Electronic address: sirajpalliyalil@gmail.com.
³ Department of Chemistry, The Gandhigram Rural Institute - Deemed to be University, Gandhigram 624302, Dindigul, Tamil Nadu, India. Electronic address: karthi2011chemistry@gmail.com.
⁴ Department of Chemistry, The Gandhigram Rural Institute - Deemed to be University, Gandhigram 624302, Dindigul, Tamil Nadu, India. Electronic address: nikitharose284@gmail.com.
⁵ Department of Chemistry, The Gandhigram Rural Institute - Deemed to be University, Gandhigram 624302, Dindigul, Tamil Nadu, India. Electronic address: ramkumarkrishnanls@gmail.com.
⁶ Department of Chemistry, The Gandhigram Rural Institute - Deemed to be University, Gandhigram 624302, Dindigul, Tamil Nadu, India. Electronic address: sankaranmeenakshi2014@gmail.com.

PMID: 33310324
DOI: 10.1016/j.jhazmat.2020.124728

Abstract

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.

Keywords: 2D/2D hybrid photocatalyst; Degradation pathway; MCP; Mineralization; TCS@MOF.

Publication types

Research Support, Non-U.S. Gov't