Synthesis of Holey Graphitic Carbon Nitride with Highly Enhanced Photocatalytic Reduction Activity via Melamine-cyanuric Acid Precursor Route

In this work, holey graphitic carbon nitride(HCN) was prepared by one-step thermal polymerization of hydrothermal product of melamine and then loaded with Ni/MoO2(NiMo) cocatalyst obtained by NaBH4 reduction process. The obtained material was used for photocatalytic production of H2 from water reduction and H2O2 production from O2 reduction. The best photocatalyst(l% NiMo/HCN) exhibited a H2 evolution rate of 8.08 Omol/h while no H2 was detected over 1% NiMo-modifed bulk g-C3N4(BCN) under visible light illumination. Moreover, this rate is 1.7 times higher than that of 1% Pt-modified HCN. The 1% NiMo/HCN catalyst also exhibited the highest H2O2 production activity with a value of 6.13 μmol/h. Such enhancement was ascribed to the efficient charge carrier separation and migration, which were promoted by the large specific surface area and pore volume of HCN and the synergy between MoO2 and Ni. The proposed method to obtain HCN is expected to open up new ways in development of highly-active HCN-based photocatalysts for photocatalytic reduction reactions.