Template-Induced High-Crystalline g-C₃N₄ Nanosheets for Enhanced Photocatalytic H₂ Evolution

High-crystalline g-C3N4 nanosheets (HC−CN) with reduced structural defects have been constructed through Ni-foam-induced thermal condensation because Ni-foam not only serves as a template for deposition of the 2D g-C3N4 nanosheets with high surface area to prevent stacking of g-C3N4 nanosheets but also acts as a catalyst to promote the polymerization and crystallization of g-C3N4 via effective dehydrogenation of the −NH2 group. The obtained HC–CN exhibits superior photocatalytic performance for H2 evolution under visible light irradiation (λ > 400 nm), which significantly benefits from the prolonged lifetime of photogenerated charge carriers and the increase of the transfer path within 2D structures of high-crystalline g-C3N4 nanosheets.