Efficient photocatalytic H2 evolution over tubular mesoporous carbon nitride with N-vacancy by microwave-assisted synthesis

Abstract

Modifying the microstructure of photocatalysts while simultaneously introducing vacancies has shown significant potential in enhancing their performance for hydrogen production. Herein, a novel tubular mesoporous carbon nitride (TMCN) with nitrogen vacancies was fabricated using a microwave-assisted synthesis strategy, employing melamine-cyanuric acid supramolecular (MC-S) as the precursor. The optimized TMCN exhibited an outstanding H₂ production rate, approximately 29 times higher than that of pristine g-C₃N₄. The N-vacancies serve as sites for reactant adsorption and activation, leading to enhanced delocalization of HOMO-LUMO. Furthermore, the porous structures of TMCN facilitate the reactant diffusion, while its tubular architectures promote the oriented transfer of charge carriers. Crucially, the markedly improved photocatalytic performance of TMCN can be predominantly attributed to the synergistic effects arising from its superior structure and N-vacancy defects. This work opens new possibilities for the simultaneous formation of surface defect states as photocatalytic reaction sites and distinctive structures conducive to charge carrier transport.