The aim of this work is the development of an effective treatment of wastewater polluted with organic compounds by green chemical techniques. Glasses and ceramics with photocatalytic properties could be applied for the decomposition of organic materials in contaminated wastewater. Hematite (α-Fe2O3) is a suitable material, due to its photocatalytic properties and low bandgap energy. In this study, we report the relationship between structure and photocatalytic ability of iron-silicate glass with the composition of xFe2O3 . (100 – x) SiO2 (in mass%, x = 10, 15 and 20), abbreviated as xFS. The samples prepared by the sol-gel method and subsequent calcination of the obtained dried gels at 1000 oC for 100 min were investigated by means of 57Fe-Mössbauer spectroscopy, X-ray diffractometry (XRD), and ultraviolet-visible light absorption spectroscopy (UV-VIS). The 57Fe-Mössbauer spectrum of xFS glass was composed of two different doublets due to fayalite with isomer shift (d) of 1.21 mm s-1 and ferrosilite with d of 1.13 mm s-1 as well as one magnetic sextet ascribed to regular hematite (α-Fe2O3: d = 0.37, quadrupole splitting of -0.2 mm s-1). Photocatalytic activity of iron-silicate glass was enhanced by increasing iron. From phenol degradation test, a remarkable decrease in its concentration was observed after 6 h when it was mixed with the 20F80S under visible-light irradiation, yielding the largest first-order rate constant of phenol decomposition of 27.3×10-2 hrs-1. It is concluded that precipitation of α-Fe2O3 in the SiO2 matrix is essential for enhancing the visible light photocatalytic activity with good recyclability.

Photocatalytic degradation of phenol by iron-silicate glass under visible light irradiation

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.