Improving the photocatalytic dye degradation performance and bactericidal properties of Brazilian Amazon Kaolin-waste by adding ZnO and Ag3PO4

New sustainable methodologies for the technological valorization of industrial residues are essential for reducing environmental problems and for obtaining materials with high added value. Herein, a microwave synthesis method was used to produce ZnO/Ag3PO4 supported in Kaolin clay (Kaolin/ZnO/Ag3PO4) and applied to Rhodamine B (RhB) dye degradation under visible light and tested as an antimicrobial agent. The calcination process at 200 oC was performed to verify if the photocatalytic and antimicrobial properties were improved. The calcined sample (KZAgc) shows a constant rate approximately 1.8 times higher than the non-calcined form in RhB dye degradation. This improved performance can be attributed to the efficient separation of photogenerated charge carriers through a Z-scheme mechanism where metallic Ag nanoparticles act as the charge transmission bridge. KZAgc sample also showed a potent antimicrobial action against Candida albicans, Staphylococcus aureus, and Escherichia coli. Therefore, the data obtained in this work demonstrate that this nanocomposite can be efficiently used for the degradation of RhB under visible light, and its calcined form can be mainly used in various environmental and medical applications due to its superior antimicrobial performance.