Synthesis of Transition Metal‐Modified Carbon Nitride Polymers for Selective Hydrocarbon Oxidation

Abstract

Modification of graphitic carbon nitride (g‐C 3 N 4) photocatalyst with transition metals was achieved with a simple soft‐chemical approach using dicyandiamide monomer and metal chloride as precursors, in combination with a thermal‐induced polycondensation at 600 °C under nitrogen atmosphere. The resultant organic–inorganic hybrid materials were thoroughly characterized by a variety of techniques, including X‐ray diffraction (XRD), UV/Vis spectroscopy, X‐ray photoelectron spectroscopy (XPS), N 2‐sorption, transmission electron microscopy (TEM), photoluminescence (PL), and FTIR. Benzene hydroxylation and styrene epoxidation reactions were employed to evaluate the catalytic/photocatalytic activity of the synthesized g‐C 3 N 4‐based catalysts. Results showed that Fe‐ and Cu‐modified g‐C 3 N 4 were active for the hydroxylation of benzene to phenol using H 2 O 2 under mild conditions. It was also found that g‐C 3 N 4 could promote the catalytic epoxidation of styrene using molecular oxygen as the primary oxidant; after modification with Co and Fe, the catalytic performance for styrene epoxidation with O 2 could be significantly improved, especially when coupled with visible‐light irradiation.