Mesoporous TiO2@g-C3N4 composite: construction, characterization, and boosting indigo carmine dye destruction

Abstract

This study articulates the fabricating of TiO2@g-C3N4 nanocomposite employing ultrasonic power starting with TiO2 and g-C3N4 as precursors. The fabricated nanostructures were characterized employing many techniques such as the X-ray diffraction (XRD), which revealed the mutual existence of g-C3N4 and anatase TiO2 phase peaks, and the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) that exposed the anchoring of TiO2 nanoparticles to the g-C3N4 layers. The coexistence of the composite constituent elements C, N, O, and Ti was verified by the energy dispersive X-ray analysis (EDX) and X-ray photoelectron spectroscopy (XPS). The composite visible-light-driven photocatalytic performance was assessed using the indigo carmine (IC) dye, and the photocatalyst demonstrated outstanding performance. The photocatalytic process fitted the pseud-first-order kinetics with a rate that is seven times faster than bare TiO2. The photocatalysis improvement could be credited to the improved porosity, the low bandgap energy and efficient recombination inhibition of the photogenerated charge carriers at the heterojunction interfaces, and prevailing photo-prompted holes electrons. The mechanistic investigation revealed that the vital species considerably contributing to the dye photodegradation were peroxide radicals and holes as interpreted from scavenger trapping experiments. The study discloses the substantiation of a Z-scheme that facilitates the electron-hole pair separation for enhanced optical characteristics.