Enhanced photocatalytic degradation of hazardous industrial pollutants with inorganic-organic TiO2-SnO2-GO hybrid nanocomposites

This study reports the photocatalytic degradation of hazardous dyes, methylene blue and reactive orange 4 (RO4) using various compositions of binary TiO2-SnO2 and ternary TiO2-SnO2-GO hybrid nanocomposites under UV-light irradiation. The ternary inorganic-organic hybrid nanocomposites degrade these dyes more efficiently as compared to binary nanocomposites. Novel addition of graphene oxide (GO) to binary composites leads to enhanced degradation ability of the resulting ternary nanocomposite, owing to increase in oxidative potential and surface to volume ratio. The structural, morphological and optical properties of the composites and their constituents have been investigated by X-ray diffraction, high-resolution transmission electron microscopy (HR-TEM), Fourier-transform infrared spectroscopy, Raman spectroscopy and UV-Vis spectroscopy. The HR-TEM images confirm the formation of inorganic-organic hybrid nanocomposites, with ternary nanocomposites having smaller particle size. Raman spectra confirm the proper mixing of various constituents of the composites. The ternary nanocomposites show ultrahigh degradation efficiency as compared to binary nanocomposites. Specifically, ternary nanocomposite with 0.10 mg GO, degraded 99.2% RO4 in just 15 min as compared to binary nanocomposite which degraded 98% RO4 in 50 min. The present study provides a new insight in the field of hybrid nanocomposite photocatalysis for degradation of hazardous dyes in wastewater.