Electrochemical degradation of indigo carmine, P-nitrosodimethylaniline and clothianidin on a fabricated Ti/SnO2-Sb/Co-βPbO2 electrode: Roles of radicals, water matrices effects and performance

Hoang Nguyen Tien; Dinh Nhi Bui; Tran Duc Manh; Nc Thuy Tram; Vu Dinh Ngo; Fredrick M Mwazighe; Hien Y Hoang; Van Thuan Le

doi:10.1016/j.chemosphere.2022.137352

Electrochemical degradation of indigo carmine, P-nitrosodimethylaniline and clothianidin on a fabricated Ti/SnO₂-Sb/Co-βPbO₂ electrode: Roles of radicals, water matrices effects and performance

Chemosphere. 2023 Feb:313:137352. doi: 10.1016/j.chemosphere.2022.137352. Epub 2022 Nov 24.

Authors

Hoang Nguyen Tien¹, Dinh Nhi Bui², Tran Duc Manh³, Nc Thuy Tram³, Vu Dinh Ngo², Fredrick M Mwazighe⁴, Hien Y Hoang⁵, Van Thuan Le⁵

Affiliations

¹ The University of Da Nang, University of Science and Education, 459 Ton Duc Thang St., Da Nang, Lien Chieu, 550000, Viet Nam. Electronic address: nthoang@ued.udn.vn.
² Faculty of Chemical and Environmental Technology, Viet Tri University of Industry, Phu Tho, Viet Nam.
³ The University of Da Nang, University of Science and Education, 459 Ton Duc Thang St., Da Nang, Lien Chieu, 550000, Viet Nam.
⁴ Department of Chemistry, Faculty of Science and Technology, University of Nairobi, P. O. Box 30197, 00100, Nairobi, Kenya.
⁵ Center for Advanced Chemistry, Institute of Research and Development, Duy Tan University, 03 Quang Trung, Da Nang, 55000, Viet Nam; The Faculty of Natural Sciences, Duy Tan University, 03 Quang Trung, Da Nang, 55000, Viet Nam.

PMID: 36436577
DOI: 10.1016/j.chemosphere.2022.137352

Abstract

In this study, the kinetic degradation of several typical organic pollutants was performed on a synthetic electrode (Ti/SnO₂-Sb/Co-βPbO₂). The surface structure and the electrochemical properties of the prepared electrode were investigated, confirming the successful preparation of the electrode using an electrochemical deposition method. The outer layer (Co-βPbO₂) played an important role in reducing the resistance of the electrode and improving its degradation efficiency. The results showed that indigo carmine (IC), p-nitrosodimethylaniline (RNO), and clothianidin (CLO) were effectively degraded within 20 min of electrolysis. Their degradation in the electrochemical process followed the first-order kinetic model with the degradation rate constant of IC being higher than that of RNO and CLO. This was proved by the difference in the reactivity of the target pollutants toward oxidizing radicals (i.e., •OH, SO₄^•-, and Cl•). Their second-order rate constant towards radicals were in the range of 10⁹ - 10¹⁰ M^-1 s^-1 with the highest value being that for IC: k_·OH,IC = 15.1 × 10⁹ M^-1 s^-1 and [Formula: see text] = 7.4 × 10⁹ M^-1 s^-1. The study calculated the contribution of some oxidizing species, including direct electron transfer (DET), •OH, SO₄^•-, and other reactive oxygen species (ROS). Solution pH, supporting electrolyte, and water matrix affected the degradation efficiency of pollutants and the contribution of the oxidizing species. Br^- and I^- ions enhanced the degradation rate of organic pollutants, while Fe²⁺, HCO₃^-, and humic acid (HA) reduced it. In addition, the toxicity, total organic carbon (TOC) removal, mineralization current efficiency (MCE), energy consumption, recyclability and stability of the prepared electrode were studied, suggesting that the prepared Ti/SnO₂-Sb/Co-βPbO₂ is a good candidate for treating organic pollutants using the electrochemical oxidation process.

Keywords: Electrochemical oxidation; Kinetic degradation; Organic pollutant; Oxidizing radicals; β-PbO(2) electrode.

MeSH terms

Electrodes
Indigo Carmine
Oxidation-Reduction
Titanium / chemistry
Water Pollutants, Chemical* / chemistry
Water*

Substances

Water
4-nitrosodimethylaniline
Indigo Carmine
clothianidin
Titanium
Water Pollutants, Chemical