Facile synthesis and comparative study of the enhanced photocatalytic degradation of two selected dyes by TiO2-g-C3N4 composite

Photocatalysis is considered a useful technique employed for the dye degradation through solar light, visible or UV light irradiation. In this study, TiO2, g-C3N4, and TiO2-g-C3N4 nanocomposites were successfully synthesized and studied for their ability to degrade Rhodamine B (RhB) and Reactive Orange 16 (RO-16), when exposed to visible light. The analytical techniques including XRD, TEM, SEM, DRS, BET, XPS, and fluorescence spectroscopy were used to explore the characteristics of all the prepared semiconductors. The photocatalytic performance of synthesized materials has been tested against both the selected dyes, and various experimental parameters were studied. The experimental results demonstrate that, in comparison to other fabricated composites, the TiO2-g-C3N4 composite with the optimal weight ratio of g-C3N4 (15 wt%) to TiO2 has shown outstanding degrading efficiency against RhB (89.62%) and RO-16 (97.20%). The degradation experiments were carried out at optimal conditions such as a catalyst load of 0.07 g, a dye concentration of 50 ppm, and a temperature of 50 ℃ at neutral pH in 90 min. In comparison to pure TiO2 and g-C3N4, the TiO2-g-C3N4, a semiconductor, has shown higher degradation efficiency due to its large surface area and decreased electron–hole recombination. The scavenger study gave an idea about the primary active species (−OH radicals), responsible for dye degradation. The reusability of TiO2-g-C3N4 was also examined in order to assess the composite sustainability.