Study of the piezo-photocatalytic efficiency of the heterostructure formed by double piezoelectric materials based on ZnO/MoS2

• Grant number: 24/16472-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2025
• End date: January 31, 2026
• Field of knowledge: Engineering - Chemical Engineering - Chemical Technology
• Principal Investigator: Liana Alvares Rodrigues
• Grantee: Paula Maria Rafaela Marcelino dos Santos
• Host Institution: Escola de Engenharia de Lorena (EEL). Universidade de São Paulo (USP). Lorena , SP, Brazil

Abstract

Industrial development has introduced new chemical substances that have, in turn, created significant environmental challenges. Emerging pollutants and persistent organic compounds pose risks to health and the environment because of their low degradability. A promising alternative for mineralizing and addressing these issues is heterogeneous photocatalysis, a green and sustainable technology that uses sunlight as its energy source. Zinc oxide (ZnO) is frequently employed as a semiconductor due to its wide bandgap and piezoelectric properties. However, its photocatalytic efficiency is limited by the high recombination rate of photo-generated charges and restricted visible light absorption. To overcome these challenges, the formation of heterojunctions between materials with different bandgaps has been explored as an intriguing strategy. Furthermore, for piezo-photocatalysts, field polarization engineering can enhance the separation of electrons and holes by using mechanical stress, which creates an internal electric field. Therefore, this project will employ these techniques in the development of XC/ZnO/MoS2 piezo-photocatalysts, aiming to enable S-scheme charge transfer stabilized by p-n type heterojunctions. Tannin-based carbon xerogel will be added to the synthesis as a redox mediator, facilitating the stabilization of the S-scheme heterojunction and increasing the light absorption capacity of the semiconductor. Both the cost and environmental impact of the carbon xerogel are lower than those of more commonly used mediators for this purpose, adding value to the project's technological innovation. The piezo-photocatalytic activity of the ternary material will be assessed through degradation tests of pollutants SA and SMZ under solar light and ultrasonic irradiation.