All-in-one photocatalyst for high performance H2 production: Ga doped polymeric carbon nitride.

A photocatalyst system is generally constructed by catalyst and cocatalyst to achieve light absorption, electron-hole separation, and surface reaction. It is a great challenge to develop a sole photocatalyst with all functions to lower the efficiency loss. Here, we integrate the active GaN4  site into polymeric carbon nitride (CN)   photocatalyst (GCN), which displays an excellent H2  production rate of 9904  μmol h-1 g-1. It is 162 and 3.3 times higher than that of  CN  with the absence  ( 61  μmolh-1 g-1)  and presence ( 2981  μmolh-1 g-1) of 1.0 wt% Pt, respectively. Under light irradiation, the electron is injected and stored at the GaN4  site, where the LUMO locates. The HOMO distributes on the aromatic ring resulting in the spatial charge separation.  T ransient photovoltage discloses the electron storage capability of GCN. The negative GaN4  promotes the proton adsorption in the excited state. The positive adsorption energy drives the H2  desorption from GaN4  after passing the electron to the proton. Our work opens up opportunities for rational design and explores the novel catalyst for H2  production.