Scalable fabrication of high surface area g-C3N4 nanotubes for efficient photocatalytic hydrogen production

In this research, we present a novel facile, scalable, and template-free technique of synthesizing graphitic carbon nitride (g-C 3 N 4 ) nanotubes for generating hydrogen through photocatalysis. The hybrid technique involves a two-fold mixing of the precursor materials melamine (M) and cyanuric acid (CA), involving ball milling followed by solution mixing. By varying the M:CA molar ratios, different compositions of g-C 3 N 4 nanotubes were fabricated. The study focused on examining the surface characteristics and the photocatalytic hydrogen evolution performance of these nanotubes. Nanotubes with high specific surface area of 206 m 2 g −1 for M:CA molar ratio of 1:3 and 178 m 2 g −1 for M:CA molar ratio of 1:5 were produced, with H 2 evolution rates of 543 μmol h −1 g −1 and 740 μmol h −1 g −1 respectively, which were an increase of 4 and 5-fold, respectively, in comparison to the pristine sample. The enhanced efficiency of hydrogen production through photocatalysis by nanotubes, when contrasted with pristine material, can be ascribed to their high crystallinity, superior specific surface areas, decreased recombination rates of electron-hole pairs generated during light exposure, and improved dynamics of charge carriers. This hybrid technique provides a new pathway for cost-effective fabrication of g-C 3 N 4 nanotubes with substantial surface areas and high yield photocatalysts on an industrial scale, without the use of templates and hydrothermal processes for efficient hydrogen generation. • Graphitic carbon nitride (g-C 3 N 4 ) nanotubes were synthesized using a novel hybrid synthesis technique involving dual precursor mixing. • High specific surface area g-C 3 N 4 nanotubes of ∼206 m 2 g −1 and 178 m 2 g −1 were achieved. • A g-C 3 N 4 nanotube with a 1:3 melamine-cyanuric acid molar ratio achieved enhanced H 2 evolution performance (740 µmol h⁻¹ g⁻¹). • The stability of g-C 3 N 4 nanotubes was shown by the consistent H 2 evolution rate during extended irradiation.