Development of Ag2SeO3-based semiconductors for antibiotic photodegradation: an innovative approach to enhance effluent treatment technologies

Abstract

The presence of antibiotics and their metabolites in the environment poses a risk to the biota at various trophic levels, including humans, and contributes to the emergence of super-resistant bacteria and microorganisms, etc. Several studies have shown a significant increase in medicine consumption worldwide, especially since the onset of the COVID-19 pandemic. The detection of highly toxic antibiotics (i.e., sulfamethoxazole-SMX and azithromycin-AZY) in effluents demonstrates the inefficiency of conventional water treatment systems. This issue has led the scientific community to seek alternative means for the effective removal of SMX, AZY, and antibiotics in general from effluents. Heterogeneous photocatalysis stands out as a cost-effective, energy-efficient treatment method compared to other procedures. In this project, the objective is to study the influence of Cu ions in the Ag2-xCux/2SeO3 (x=0, 1, 2, 4, 8 mmol%) system synthesized by the sonochemical method on the photodegradation of SMX and AZY. With the intention of establishing metal (Ag/Cu)-semiconductor (n-type) heterojunctions, the materials will be irradiated with femtosecond electron and laser beams. Due to the formation of reactive groups on the semiconductor surface, responsible for the mineralization of contaminating organic molecules, it is expected to obtain a material with superior photocatalytic response. Its long/medium/short-range structure will be characterized by combining techniques such as X-ray diffraction (XRD), photoluminescence/UV-Vis spectroscopies, Raman spectroscopy, X-ray absorption (XANES/EXAFS), X-ray photoelectron spectroscopy (XPS), among others. The morphology will be evaluated using scanning (SEM) and transmission electron microscopy (TEM) techniques. Experimentally obtained results will be correlated with theoretical simulations to elucidate and describe the mechanisms associated with the degradation of SMX and AZY compounds in domestic effluent. To this date, there is no integrated study in the literature correlating the structure, morphology, theory, and photocatalytic properties of Ag2SeO3-based materials for the degradation of antibiotics in effluents. This research proposal is innovative from a scientific, technological, and sustainability perspective, aiming to address a relevant societal issue exacerbated by the COVID-19 pandemic.