Morphology engineering of carbon nitride boosts visible-light photocatalytic hydrogen evolution

Carbon nitride (CN) is a promising metal-free photocatalyst for solar-driven H 2 production, yet its efficiency is severely limited by low specific surface area and rapid charge recombination. Herein, air-thermal treatment with tunable heating rates enables precise morphological control of CN, yielding "flower-bud"-like aggregates, porous networks, and nanosheets, with specific surface area increasing from 9.9 to 212.6 m 2 g −1 and pore volume surging from 0.04 to 0.76 cm 3 g −1 . Exfoliated nanostructures demonstrate augmented reduction potential alongside enhanced charge separation and transport efficiency, thereby significantly improving its photocatalytic H 2 evolution performance. This work establishes heating rate as a powerful parameter for CN performance enhancement, offering a scalable route to high-efficiency photocatalysts for sustainable solar-to-fuel conversion.