Sunlight assisted photocatalytic degradation of organic pollutants using g-C3N4-TiO2 nanocomposites

Abstract

The photocatalytic degradation of environmentally non-benign, toxic organic pollutants such as bisphenol A (BPA), brilliant green (BG), or mixture of dyes have been carried out using g-C3N4-TiO2 (GNT) nanocomposites. The GNT nanocomposites were synthesized by using hydrothermal method with different compositions and these nanocomposites were characterized using the different techniques. X-ray diffraction revealed that the anatase phase of TiO2 has been retained in composites; while characteristic reflection of g-C3N4 at 27.07° (d = 3.22 Å) is not observed due to its lower content in the nanocomposites. Raman spectra confirms the formation of composites between TiO2 with g-C3N4. Furthermore nano-scale dimensions of the bare or composites have been proved by FE-SEM and HR-TEM analysis. X-ray photoelectron spectroscopy (XPS) shows the presence of C, N, Ti and O as a constituents, with peaks due to CC, NCN of g-C3N4. Among the different nanocomposites, g-C3N4-TiO2 catalyst having 30% g-C3N4 and 70% TiO2 in molar proportion (i.e. 30-GNT) is exhibiting the highest efficiency for degradation of the different dyes in correlation to its higher surface area, lower optical band gap as well as more visible-light absorption (i.e., λ > 400 nm) in the electromagnetic spectrum. Keywords: Nanocomposites, TiO2, g-C3N4, Photocatalytic degradation, Bisphenol A, Brilliant green