Modification of graphite carbon nitride by adding an ultra-micro amount of triaminotriphenylamine for superior photocatalytic hydrogen evolution

Abstract

In this paper, a novel pristine carbon nitride (np-CN) with hollow capsule-like morphology was facilely prepared by the thermal polymerization of melamine and cyanuric chloride at 550 °C in air for 4 h. Then, modified carbon nitride (CN-P_4mg) micro-flakes with zigzag edges were synthesized by the copolymerization of melamine, cyanuric chloride, and triaminotriphenylamine with a mass fraction of 0.13%. Analysis of the microstructure, surface state, porosity, and optoelectronic properties of the two samples indicates that CN-P_4mg has a larger specific surface area and a lower bandgap than np-CN. Under visible light, CN-P_4mg displays enhanced photocatalytic performance for the generation of hydrogen compared to that of np-CN and bulk graphite carbon nitride (g-C₃N₄). The photocatalytic hydrogen evolution rate of CN-P_4mg reaches 16897.3 μmol g⁻¹ h⁻¹, which is 1.84 times that of np-CN and 72 times that of bulk g-C₃N₄. The experimental results confirm that the addition of triaminotriphenylamine provides a modified design for developing metal-free carbon nitride derivatives and a new route to study efficient photocatalytic materials.