Photocatalytic activity of CoFe2O4/g-C3N4 nanocomposite toward degradation of different organic pollutants and their inactivity toward hydrogen production: The role of the conduction band position

Recently, graphitic carbon nitride (g-C3N4)-based composite photocatalyst has been investigated as a promising photocatalyst for degradation of organic pollutants. In this paper, a simple calcination method was used to prepare CoFe2O4/g-C3N4 p-n heterojunction photocatalysts. The morphological structure, optical, and electrochemical properties of the as-synthesized CoFe2O4/g-C3N4 p-n junction photocatalysts were characterized. Furthermore, the photocatalytic activity of the CoFe2O4/g-C3N4 p-n junction photocatalysts was evaluated not only for degradation of methyl orange (MO) but also for non-colored 4-chlorophenol (4-CP) under visible light irradiation. The 3% CoFe2O4/g-C3N4 of showed the highest photocatalytic activity that can activate H2O2 and degrade MO up to 98% in 4 h. The remarkable enhancement was mainly ascribed to the interfacial transfer of photogenerated charge carriers and the role of H2O2 in the generation of more hydroxyl radicals via photo-Fenton-like reaction. Additionally, scavenger experiments showed that hydroxyl radicals are the dominant active oxygen species responsible for the photodegradation reaction, while superoxide radicals play a minor role. Importantly, this composite showed no activity toward hydrogen production due to the positive band position of CoFe2O4. This work may provide a simple and low-cost method for large-scale production of visible-light-active photocatalyst that can be applied for environmental remediation applications.