Development of photoelectrodes based on semiconductor oxide heterojunctions for photo electrooxidation of microplastics: nanocomposites based on TiO2, WO3, Ag3PO4, and KNbO3

• Grant number: 25/01477-2
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: June 01, 2025
• End date: May 31, 2026
• Field of knowledge: Engineering - Sanitary Engineering - Water Supply and Wastewater Treatment
• Principal Investigator: Maria Valnice Boldrin
• Grantee: Rodrigo de Mello
• Supervisor: Annalisa Vacca
• Host Institution: Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil
• Institution abroad: Università di Cagliari, Italy
• Associated to the scholarship: 22/14679-4 - Synthesis, characterization and application of heterojunctions of Ag3PO4/KNbO3 semiconductor oxides in the oxidation of microplastics by photocatalytic, photoelectrocatalytic and modified membranes methods, BP.PD

Abstract

The increasing use of plastics in modern society has sparked environmental concerns, particularly related to their improper disposal and the resulting contamination of aquatic ecosystems. Microplastics, derived from the fragmentation of larger plastic items, pose a unique challenge due to their small size and persistence in water bodies. This project seeks to develop innovative approaches for the treatment of water contaminated by microplastics, specifically focusing on polypropylene (PP) and polyethylene (PE), which are prevalent in industrial applications. This research will employ both photocatalytic and photoelectrocatalytic techniques to enhance the breakdown of these pollutants. To address challenges encountered in earlier experiments, the project will focus on optimizing the photoelectrocatalytic efficiency through the incorporation of KNbO3 into TiO2 nanotube substrates, forming a novel heterojunction. Following the identification of optimal conditions, additional heterojunctions with Ag3PO4 and TiO2 nanotubes will be explored, alongside the substitution of the titanium substrate with WO3 for further performance improvements. Professor Annalisa Vacca, renowned for her expertise in semiconductor metal oxides and microplastic degradation via photoelectrocatalysis, will contribute her specialized knowledge to this endeavor. The project's success will be measured through comprehensive analyses, including scanning electron microscopy (SEM), gas chromatography with pyrolysis, FTIR, and total organic carbon removal assessments. These evaluations will focus on particle size reduction, monomer production and degradation, chemical structure changes in the polymers, and the mineralization of organic matter.