Evaluation of WO3-Ag-AgCl photocatalytic films immobilized on glass substrates using a flat plate photochemical reactor for degradation of pollutants

• Grant number: 23/03880-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): June 01, 2023
• Effective date (End): May 31, 2024
• Field of knowledge: Engineering - Chemical Engineering - Chemical Process Industries
• Principal Investigator: Antonio Carlos Silva Costa Teixeira
• Grantee: Rodrigo Koester Santos Pereira
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Advanced oxidative processes (AOP) have gained prominence as an alternative to efficiently remove several contaminants of emerging concern from water and wastewater. There is special emphasis on the use of active photocatalysts in the visible range, synthesized by doping semiconductors with noble metals or by obtaining heterojunctions. As an example of such materials, mention is made of tungsten trioxide doped with silver and/or coupled with silver-based materials, such as silver chloride. Another important way to increase the efficiency of the photocatalytic process is to select the type of reactor to be used in the process. The immobilization of photocatalysts in continuous flow reactors is an interesting option, allowing the use of a reduced amount of material, seeking to increase the area of the photocatalytic surface exposed to light and avoid costly operations of separating the photocatalyst after treatment, as is the case of systems in suspension. Among the various methods of synthesis of immobilized photocatalysts, the spray-pyrolysis technique and its variations (ultrasonic spray- pyrolysis, for example) stands out for being a cheap, versatile, fast and reproducible method. Thus, this project aims to obtain WO3-Ag-AgCl films immobilized on borosilicate glass substrates by the method of ultrasonic spray- pyrolysis/photoreduction, for application in a continuous flow flat plate photochemical reactor. The reactor and the photocatalysts will be studied for the photodegradation of the model pollutant acetaminophen, evaluating optimal conditions of simulated solar irradiance, UV-A LEDs for compensation of solar irradiation, as well as the optimal residence time in the reactor and the stability of the photocatalytic films.