Synergy of defect engineering and curvature effect for porous graphite carbon nitride nanotubes promoted photocatalytic hydrogen evolution

Graphite carbon nitride (g-C₃N₄) nanotubes have received extensive attention due to its unique morphology and electronic migration. Herein, the defective porous g-C₃N₄ nanotube (DTCN) is prepared through a simple thermal reduction process. The construction of N vacancy and tubular structure can synergistically promote the separation of photogenerated charge carriers. As a result, DTCN demonstrates a higher photocatalytic hydrogen evolution rate (1440 μmol·g⁻¹·h⁻¹), which is 5 times higher than that of the initial g-C₃N₄ nanotube (TCN). Importantly, combined with density functional theory calculations and experimental results, it is the first time to prove that the synergy of curvature effect and N vacancy of nanotubes can enhance the adsorption energy of hydrogen and decrease the work function, resulting in more superior photocatalytic performance than the layered structure. This work provides more in-depth comprehension for the photocatalytic mechanism of nanotube materials, which has inspirational significance for the design of the g-C₃N₄ photocatalyst with high performance.