A photochemical route in the synthesis and characterization of La2Ti2O7 and La2Ti2O7/AgO films and its evaluation in Congo red degradation and as antibacterial control to Staphylococcus aureus

Abstract

In this article, we propose a simple photochemical method to synthesize pure La₂Ti₂O₇ films and La₂Ti₂O₇ films doped with silver at 1.0, 3.0, and 5.0 mol%. After annealing the photo-deposited films at 900 °C, XRD, SEM, and XPS analyses showed the formation of a monoclinic La₂Ti₂O₇ phase and the presence of Ag and AgO in doped samples. Photocatalytic tests for Congo red degradation demonstrated that pure La₂Ti₂O₇ achieved 25.4% degradation, while doped samples reached a maximum of 92.7% degradation. Moreover, increasing silver doping on La₂Ti₂O₇ films significantly reduced the growth of Staphylococcus aureus, indicating potential antibacterial properties. The enhanced photoactivity was attributed to the formation of a type I heterojunction between La₂Ti₂O₇ and AgO, and a degradation mechanism was proposed based on Congo red degradation.

Keywords: Congo red (CR); La2Ti2O7 films; Photocatalyst; Photochemical deposition; Staphylococcus aureus (S. aureus).