Surface hydrogen bonding can enhance photocatalytic H2 evolution efficiency

Abstract

Hydrogen bonding (H-bond) interactions have been regarded as a topic of vital scientific research in areas ranging from inorganic to biological chemistry. However, the application and elucidation of surface H-bond functionalized photocatalysts and the alteration of the character of the photocatalyst itself have not been paid sufficient attention. Here we show the high efficiency of visible-light-driven photocatalytic H₂ production, achieved by using a surface H-bonding network decorated g-C₃N₄ photocatalyst. The hydrated g-C₃N₄ was designed and synthesized by a facile surface treatment in a slightly alkaline environment. According to NMR and theoretical modeling, the H-bonding bridge can effectively shorten the distance between water molecules and g-C₃N₄, provide multiple channels for the transition between protons and the excited electrons on g-C₃N₄, stabilize the anionic intermediate and transition states, and restrain charge recombination. The present result opens new opportunities towards a potential approach to designing a new generation of photocatalyst systems.