Strengthened spatial charge separation over Z-scheme heterojunction photocatalyst for efficient photocatalytic H ₂ evolution

Graphitic carbon nitride (g-C ₃ N ₄ ) is a very promising earth abundant and visible light response photocatalyst for H ₂ production. Fabricating novel nanostructure or combining with other semiconductors have been attempted to further enhance its activity. α-FeOOH, due to its structures greatly facilitating electrolyte transport, has been widely used as an excellent OER cocatalyst assisting the PEC water splitting process. However, to the best of our knowledge, it has not been attempted in photocatalytic H ₂ generation. Herein, g-C ₃ N ₄ modified with β-FeOOH was designed for the first time for photocatalytic H ₂ production. It showed H ₂ production rate as 2.02 mmol·h ⁻¹ ·g ⁻¹ , which was almost 6 times of pure g-C ₃ N ₄ . The significantly promoted catalytic activity was ascribed to the greatly enhanced charge separation efficiency by forming spatial separated reservoirs of photo activated electrons and holes in the Z-scheme heterojunction, corresponding to the conduction band of g-C ₃ N ₄ and the valence band of β-FeOOH, respectively. Our work should be valuable for fabricating visible-light response heterojunction based photocatalysts with better photocatalytic performance.