Photoelectrocatalytic degradation of high-density polyethylene microplastics on TiO2-modified boron-doped diamond photoanode

Wendy Quilumbaquin; G Xavier Castillo-Cabrera; Luis J Borrero-González; José R Mora; Vladimir Valle; Alexis Debut; Luis D Loor-Urgilés; Patricio J Espinoza-Montero

doi:10.1016/j.isci.2024.109192

Photoelectrocatalytic degradation of high-density polyethylene microplastics on TiO₂-modified boron-doped diamond photoanode

iScience. 2024 Feb 12;27(3):109192. doi: 10.1016/j.isci.2024.109192. eCollection 2024 Mar 15.

Authors

Wendy Quilumbaquin¹, G Xavier Castillo-Cabrera¹, Luis J Borrero-González², José R Mora³, Vladimir Valle⁴, Alexis Debut⁵, Luis D Loor-Urgilés¹, Patricio J Espinoza-Montero¹

Affiliations

¹ Escuela de Ciencias Químicas, Pontificia Universidad Católica del Ecuador, Quito 170525, Ecuador.
² Laboratorio de Óptica Aplicada, Escuela de Ciencias Físicas y Matemática, Pontificia Universidad Católica del Ecuador, Quito 170525, Ecuador.
³ Department of Chemical Engineering, Universidad San Francisco de Quito USFQ, Quito 170157, Ecuador.
⁴ Departamento de Ciencias de Alimentos y Biotecnología, Escuela Politécnica Nacional, Quito 170517, Ecuador.
⁵ Centro de Nanociencia y Nanotecnología, Universidad de las Fuerzas Armadas ESPE, Sangolquí 170501, Ecuador.

Abstract

Microplastic (MP) accumulation in the environment is accelerating rapidly, which has led to their effects on both the ecosystem and human life garnering much attention. This study is the first to examine the degradation of high-density polyethylene (HDPE) MPs via photoelectrocatalysis (PEC) using a TiO₂-modified boron-doped diamond (BDD/TiO₂) photoanode. This study was divided into three stages: (i) preparation of the photoanode through electrophoretic deposition of synthetic TiO₂ nanoparticles on a BDD electrode; (ii) characterization of the modified photoanode using electrochemical, structural, and optical techniques; and (iii) degradation of HDPE MPs by electrochemical oxidation and photoelectrocatalysis on bare and modified BDD electrodes under dark and UV light conditions. The results indicate that the PEC technique degraded 89.91 ± 0.08% of HDPE MPs in a 10-h reaction and was more efficient at a lower current density (6.89 mA cm^-1) with the BDD/TiO₂ photoanode compared to electrochemical oxidation on bare BDD.

Keywords: Devices; Materials chemistry.