Photocatalyst for High-Performance H₂ Production: Ga-Doped Polymeric Carbon Nitride

A photocatalyst system is generally comprises a catalyst and cocatalyst to achieve light absorption, electron-hole separation, and surface reaction. It is a challenge to develop a single photocatalyst having all functions so as to lower the efficiency loss. Herein, the active GaN₄ site is integrated into a 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 μmol h^-1  g^-1 ) and presence (2981 μmol h^-1  g^-1 ), respectively, of 1.0 wt % Pt. 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 spatial charge separation. Transient photovoltage discloses the electron-storage capability of GCN. The negative GaN₄ promotes proton adsorption in the excited state. The positive adsorption energy drives H₂ desorption from GaN₄ after passing the electron to the proton. This work opens up opportunities for exploring a novel catalyst for H₂ production.