Synthesizing crystalline g-C3N4 for enhanced photocatalytic hydrogen evolution under visible light

Abstract

A novel crystalline hexagonal prism g-C₃N₄ (HPCN) was synthesized through hydrothermal recrystallization of flaky g-C₃N₄. HPCN exhibits higher-efficiency separation of photocarriers and faster photoelectron transfer along the (002) crystal facet than calcination-formed flaky g-C₃N₄ (UCN). This significantly shortens the average lifetime of photogenerated carriers in HPCN to 6.0 ns compared with UCN of 15.5 ns. Under visible-light irradiation, the photocatalytic hydrogen evolution of HPCN reaches 1846 μmol g⁻¹ h⁻¹, and demonstrates excellent photocatalytic stability.