Photoelectrocatalyzed degradation of a pesticides mixture solution (chlorfenvinphos and bromacil) by WO3 nanosheets

Abstract

A photoelectrocatalyst consisting of WO3 nanosheets or nanorods has been synthesized by electrochemical anodization under hydrodynamic conditions, and has been used for the degradation of two toxic pesticides: chlorfenvinphos and bromacil. Nanostructures have been characterized by FESEM and Raman spectroscopy. Photoelectrochemical degradation tests have been carried out both for individual pesticide solutions and for a mixture solution, and the concentration evolution with time has been followed by UV-Vis spectrophotometry. For individual pesticides, pseudo-first order kinetic coefficients of 0.402 h -1 and 0.324 h -1 have been obtained for chlorfenvinphos and bromacil, respectively, while for the mixture solution, these kinetic coefficients have been 0.162 h -1 and 0.408 h -1 . The change in behavior towards pesticide degradation depending on whether individual or mixture solutions were used might be indicative of a competitive process between the two pesticide molecules when interacting with the WO3 nanostructures surface or when approaching the semiconductor/electrolyte interface.

Visible Light–Driven Advanced Oxidation Processes to Remove Emerging Contaminants from Water and Wastewater: a Review

“…In the model solution at pH = 3, due to the change in hydrophobic properties of TiO 2 modified with organic acids, the mechanism involves the adsorption of CVFP on the catalyst surface, followed by cleavage of the aromatic ring by oxidizing radicals, mainly Zawadzki ( 2020 ) Chlorfenvinphos Visible light–driven photoelectrochemical degradation in the presence of WO 3 nanorods Degradation in the presence of WO 3 nanotubes occurs by cleavage of the aromatic ring (π-π*). The time evolution of the UV absorption spectra of CFVP took values greater than 0, which means that the degradation of CFVP probably takes place by opening the aromatic ring and then generating intermediate compounds Degradation by hydroxyl radicals or directly with photodegenerated holes on the WO 3 surface in semiconductor/electrolyte solution Further analytical work is needed to propose the full mechanism of chlorfenvinphos degradation in the presence of WO 3 nanotubes Fernández-Domene et al ( 2019 ) Roselló-Márquez et al ( 2019 ) Chlorfenvinphos Photodegradation by using WO 3 nanostructures • OH radicals are used as the main oxidizing agent for the degradation of CFVP. The photodegradation pathway of CFVP involves decomposition to a phosphate group, opening of the aromatic ring, or decomposition of the CFVP molecule by binding to phosphorus, with the formation of compounds without chlorine atoms and with longer aliphatic chains.…”

Biomimicry designs for photoelectrochemical systems: Strategies to improve light delivery efficiency

“…The charge carrier h + VB generates the strong oxidant hydroxyl radical ( • OH) from water oxidation among other oxygen reactive species [15][16][17][18]. The oxidants produced degrade organic pollutants till their complete incineration to CO2 and enable bacteria inactivation mechanisms [19][20][21][22][23][24].…”

Controllable Preparation of 2D V2O5 Peroxidase‐Mimetic Nanozyme to Develop Portable Paper‐Based Analytical Device for Intelligent Pesticide Assay

“…Since the breakthrough investigation by Geim and Novoselov, 2D nanosheet, featuring high light-absorbing capacity, increased responder locus, accelerated carrier separation and charge transfer, and ameliorative surface-catalyzed reaction efficiency, has indeed emerged as a novel material for application in many fields, [14][15][16][17][18][19][20] such as electrocatalysis, [21] photocatalysis, [22] biomedical engineering, [23,24] optoelectronic, [25,26] and biological and chemical sensing. [27][28][29][30][31] Moreover, via ingeniously adjusting the morphology and composition, the as-prepared 2D nanosheet may have unimagined "bioenyzme-mimetic" activity, named 2D nanozyme, which shows great applications in catalytic oxidation for target analyte sensing, an emerging pesticideresponse modality. [32] These so-called "2D nanozyme" may demonstrate unique superiorities over other nanozymes with morphologies of nanocluster, nano/microparticle, and nanofiber/ rod due to the intrinsic characteristics.…”