Title : Facile fabrication of SnO2/g-C3N4 photocatalysts for the degradation of endocrine disruptors and pharmaceutical drugs in natural sunlight exposure
Abstract:
The present investigation primarily concentrates on the surface alteration of pure g-C3N4 by SnO2 to expand the life span of excitons. The pure and SnO2 loaded g-C3N4 photocatalysts in various compositions were synthesized and characterized by UV-vis diffuse reflectance spectroscopy, photoluminescence, FESEM, HRTEM and XPS. The absorption spectra of SnO2 loaded g-C3N4 revealed the red shift in the band energy. The successive decrease in the PL spectra with the increase of loading authenticates the supporting role of SnO2 in extending the life span of excitons. The charge retention ability was estimated by electrochemical measurements whereas the SPIES measurements coupled with Mott-Schottky analysis facilitated the fetching of the flat band potential as well as the semiconducting electrical nature of the materials. The as-synthesized SnO2 loaded g-C3N4 photocatalysts displayed an enhanced activity as compared to pure g-C3N4 for the degradation and mineralization of BPA, tetracycline, diclofenac and oxacillin in natural sunlight exposure. The progress of BPA and drugs degradation was monitored by HPLS and UV-visible spectroscopy respectively. The total organic carbon (TOC) and ion chromatography (IC) measurements helped in the estimation of the mineralization efficiency of impregnated materials. The contribution of both hydroxyl (OH•) and superoxide anion (O2•-) radicals in the degradation/mineralization process. The maximum degradation was achieved over 3% SnO2 loaded g-C3N4 in the order of diclofenac (97%) > chlortetracycline (95) > BPA (88%) > Oxacillin (80%). The information collected from the analytical tools correlated to propose the plausible mechanism of the degrading/mineralization process.
