Facile fabrication of Tl4HgI6 nanostructures as novel antibacterial and antibiofilm agents and photocatalysts in the degradation of organic pollutants

Abstract

Semiconductor photocatalysis has drawn much consideration from scientists in the current decade. The photocatalytic procedure is an eco-friendly process that has been recognized as a promising alternative for the removal of several hazardous pollutants. The deficiencies of current photocatalytic systems, which limit their technical applications, include low-utilization of visible radiation, fast charge recombination, and low migration capacity of the photo-induced electron-holes. In the present study, Tl₄HgI₆ nanostructures have been successfully fabricated through a simple precipitation route. The impact of the TlI stoichiometric ratio to HgI₂, and the types of surfactants was explored in terms of the purity, structure, scale, and shape of the samples. The bandgap of nano-Tl₄HgI₆ was evaluated via diffuse reflectance spectroscopy (DRS) to be around 2.05 eV, which is suitable for photocatalytic performance. Raman spectroscopy results corroborated the X-ray diffractometry results and revealed that the Tl₄HgI₆ nanoparticles were successfully fabricated. The structure, shape, and scale of the products were studied by field emission scanning electron microscopy. It was observed that different factors had a notable effect on the morphology and size of the products. The maximum antibacterial activity of Tl₄HgI₆ was determined against S. aureus, E. coli, and M. catarrhalis. These outcomes demonstrated that Tl₄HgI₆ displays efficient bactericidal activity against Gram-positive and Gram-negative microorganisms. The anti-biofilm activity revealed that the best biofilm decrease was recognized at higher Tl₄HgI₆ concentrations (2 × the minimum inhibitory concentration). This represents the first study of the investigation of the photocatalytic activity of Tl₄HgI₆ nanostructures. The photocatalytic performance was studied to eliminate various dyes and with different dosages of the catalyst under UV and visible light. The results indicate that these nanoparticles can remove organic dyes with high efficiency.