Photocatalytic performance of Anatase/Rutile TiO2 composite against different organic dyes

Abstract

Organic waste dyes from textile industries are considered to be significant environmental wastewater. In general, wastewater treatment using photocatalytic degradation via a semiconductor is an advanced technology,
due to the high photocatalytic efficiency of the semiconductor, the environmentally friendly nature of the process, the low-cost of materials needed and the free energy available for consumption from sunlight. Recently, an anatase/rutile titanium dioxide (TiO2) composite has been widely studied, due to its unique optical property as a photocatalyst, which is more effective than the pure phase. In this work, an anatase/rutile titania mixed phase
composite was prepared by a simple mechanical method. The degradation mechanisms of specific organic dyes are different, resulting in a difference of degradation performance. This research was conducted in order to study
the photocatalytic performance of an anatase/rutile titanium dioxide (TiO2) composite, prepared from commercial TiO
2 by ball-mill techniques, against three types of dyes including methylene blue (MB), methyl orange (MO), and Rhodamine B (RhB). Phase ratios of the composites were evaluated by X-ray diffraction (XRD) and confirmed by
Raman spectroscopy. Their morphologies were monitored by a scanning electron microscope (SEM). We have reported the optimized condition of various anatase/rutile titanium dioxide phase ratios necessary, for a high
synergistic effect of each organic dye type. The photocatalytic activities of the titania catalyst, for all three dyes degradation under visible light irradiation were also scrutinized. The results revealed that the prepared
anatase/rutile TiO2 composites, can provide significant enhancement in photocatalytic efficiency for MB, MO and
RhB textile dye degradation.