Enhanced photocatalytic performance of polymeric carbon nitride through combination of iron loading and hydrogen peroxide treatment

Polymeric carbon nitride (p-C3N4) based materials have shown great potential as photocatalysts for degradation of pollutants from wastewater. In this work p-C3N4 was synthesized from urea or ferric chloride/urea by pyrolysis followed by a post-treatment with hydrogen peroxide (H2O2). The prepared materials were characterized by physico-chemical methods in order to study their structural and electronic features. The characterization results revealed that iron was present in p-C3N4 as a Fe3O4 phase. The H2O2 treatment did not only modify the p-C3N4 framework through the generation of oxygen functional groups and defect sites but it also affected the size, distribution, and oxidation state of iron oxide. The photocatalytic activity of the catalysts was tested through the degradation of methyl orange under visible and white light irradiation. In comparison, the iron oxide containing p-C3N4 post-treated with H2O2 sample shows superior photocatalytic performance towards methyl orange degradation. This might be attributed to the valence and conduction band levels of the composite material, an inhibited recombination of photogenerated charge carriers as well as a synergistic effect of iron species and the oxygen containing functional groups or defects present in p-C3N4.