"Development of 2D Materials based on Sulfide and Tin Oxide Doped with Rare Earth Ions for Application in Heterogeneous Photocatalysis assisted by visible light"

Abstract

The presence of antibiotics in wastewater is a growing universal problem that can affect human health and the environment. Studies and new technologies for removing these pharmaceutical residues are found in the literature, among which heterogeneous photocatalysis is a promising process in the search for sustainable solutions to these environmental challenges, especially when combined with sunlight. The application of 2D materials based on semiconductors, such as sulfide and tin oxide, represents an alternative material for the photocatalytic process due especially to their multifunctional properties such as good chemical and thermal stability, low toxicity, high surface area, absorption in the UV-A and visible light, in addition to presenting defects in their structure, which can favor their catalytic properties, and variation in the band gap towards regions of lower energy (visible).This project consists of the synthesis and characterization of 2D materials based on sulfide and tin oxide doped with rare earth ions through different synthetic routes aiming for applications in the heterogeneous photocatalysis process, for the removal of antibiotics present in wastewater. A systematic study of the compounds and their optical, structural, morphological, and spectroscopic (vibrational and electronic) properties will be carried out, seeking to obtain multifunctional materials for applications in Photonics. As lanthanide ions will be used as dopants, Eu3+ ions will be used as structure probes, allowing the investigation of the local structure of the symmetry site occupied by lanthanide ions in the compound; in addition to other lanthanide ions (such as Er3+, Tm3+ and Yb3+) that present attractive energy levels and photophysical processes for expanding the absorption range of the solar spectrum for the application of the photocatalysis process assisted by up conversion process from near infrared to visible.More specifically, the project presents the following steps: i) synthesis and characterization of 2D materials based on SnS2, synthesis of SnO2 and hybrid compounds containing both SnS2 and SnO2 varying their structural and electronic properties and ii) doped with Eu3+, Er3+ and Yb3+ ions ; iii) thin film deposition and study of their optical properties; iv) Formation of 2D SnS2 on the surface of luminescent particles with high quantum yield of up conversion process (rare earth fluorides and yttrium stannate co-doped with Er3+ and Yb3+ and Tm3+ and Yb3+ e ions), excellent infrared converters to the visible region to explore the concept of photocatalysis assisted by upconversion mechanisms; v) Application of materials in the heterogeneous photocatalysis process in the degradation of antibiotics tetracycline hydrochloride, sulfamethoxazole, ciprofloxacin, cephalexin and amoxicillin in purified water; and finally vi) Investigation of the performance of catalytic systems in removing antibiotics present in hospital wastewater (case study).