Development of Nb2O5/g-C3N4 heterostructures decorated with Cu and Zn nanoparticles for CO2 photoconversion into chemical industry products.

• Grant number: 23/02814-7
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: April 01, 2023
• End date: March 31, 2027
• Field of knowledge: Engineering - Chemical Engineering - Chemical Technology
• Principal Investigator: Francisco Guilherme Esteves Nogueira
• Grantee: Alejandro Sifuentes Clemente
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated research grant: 22/02980-1 - Development of semiconductors for photoconversion of CO2 into solar fuels and products for the chemical industry, AP.PNGP.PI

Abstract

In the last decades, the concentration of greenhouse gases has significantly increased. Among these gases, carbon dioxide (CO2) stands out, which is emitted by the burning of fossil fuels and industrial activities such as cement production, steelmaking, and petrochemical refining, among others. Therefore, the development of technologies for CO2 reduction or conversion is essential and strategic for Brazil's environmental and economic development. In this context, photocatalytic processes are highlighted, which can use solar light as an energy source for the process.Thus, the objective of this project is to develop heterostructures based on Nb2O5 and g-C3N4 decorated with Cu and Zn, as the coupling between semiconductors can improve the separation of photo-generated charges (electron (e-)/hole (h+)), reducing the recombination rate between them. Heterostructures materials exhibit different compositions or structures that share the same interface (heterojunction) between any two materials in the solid state. The development of these systems enables the control of several fundamental parameters involved in photocatalytic processes, such as carrier mobility, band gap, and refractive index, among others.However, for the development of heterostructures semiconductors with high activity in the visible region and stability over long periods of operation, systematic studies are still needed to propose more efficient synthesis strategies, aiming to ensure control of the desired proportion, as well as their morphological, structural and electronic characteristics, especially in larger-scale productionThus, the specific goals of this proposal are the synthesis and study of Nb2O5/g-C3N4-based heterostructures in different ratios of Nb2O5 and g-C3N4. Additionally, the heterostructure that presents the best photocatalytic activity for the CO2 photoconversion reaction will be decorated with Cu or Zn at different levels, through wet impregnation and cathodic sputtering deposition methods (DC-magnetron sputtering), as the addition of a transition metal in these materials can contribute to increasing the carrier lifetime and interaction with CO2.