Synthesis and structural morphological characteristics of graphitic carbon nitride modified with polar hydroxyl groups

Keywords

synthesis, graphitic carbon nitride, surface modification, hydroxyl groups, ultrasonic treatment, hydrogen peroxide, photocatalyst.

Cite as

Sukhatskiy Y. V., Shepida М. V., and Korniy S. A. Synthesis and structural morphological characteristics of graphitic carbon nitride modified with polar hydroxyl groups. Physicochemical Mechanics of Materials. 2026. 62(4), 51-56.

Abstract

The surface of g-C₃N₄ was modified with polar hydroxyl groups through g-C₃N₄ treating with an aqueous solution of hydrogen peroxide in an ultrasonic (US) field. The diffraction patterns showed a shift of the diffraction peaks corresponding to the (002) plane for modified g-C₃N₄ samples towards larger values of 2q angles (from 27.3 to 27.4°) compared to un­modified g-C₃N₄, which indicated a decrease in the interlayer distance of the photocatalysts (from 0.3266 to 0.3254 nm) and, accordingly, an increased rate of charge carrier transfer. Scanning electron microscopy and energy-dispersive X-ray analysis confirmed an increase in the content of hydroxyl groups on the g-C₃N₄ surface with increasing the duration of US treatment. The chemical structure of modified g-C₃N₄ was evaluated by Fourier transform infrared spectroscopy. A significant decrease in the absorption intensity in the range of 3000–3400 cm^–1 was found with US treatment duration of 60 min, which can be explained by possible exfoliation of g-C₃N₄ layers and fracture of interlayer hydrogen bonds, oxidation of hydroxyl groups on the g-C₃N₄ surface to carboxyl groups, or “screening” of hydroxyl groups due to steric hindrance.