Photo-Fenton reaction enhanced visible-light activity of p- Photo-Fenton reaction enhanced visible-light activity of p-CuFe2O4/n-g-C3N4 heterojunction composites synthesized by a simple ultrasonic-assisted route for organic pollutants degradation

In this work, p-n type (type II) heterojunction (CuFe2O4/g-C3N4) photocatalyst was used to purify methyl orange (MO), 4-chlorophenol (4-CP), and 4-nitrophenol (4-NP) in wastewater. The heterojunction photocatalysts with varying CuFe2O4 mass concentrations were synthesized using a novel ultrasonic-assisted technique. Heterojunction formation between CuFe2O4 and g-C3N4 was verified using a high-resolution transmission electron microscope. Effective charge separation efficiency was identified through photocurrent and electrochemical impedance spectroscopy. The wrapped of CuFe2O4 on the g-C3N4 was also confirmed by X-ray photoelectron spectroscopy. According to Mott-Schottky analysis, p-type CuFe2O4 has a lower flat band potential than n-type g-C3N4. The results indicated that the composite of 8% CuFe2O4 /g-C3N4 displayed the highest photocatalytic activity in the presence of H2O2 as an oxidant. It could strongly activate H2O2 to degrade MO (∼98%) in 3 h under visible light irradiation. This remarkable enhancement of the photocatalytic activity could be assigned to the excellent electron transfer efficiency on the interface and the involvement of H2O2 in the creation of additional hydroxyl radicals, which reinforce the photocatalytic performance. Additionally, this heterojunction composite showed the highest photocatalytic hydrogen production activity in the presence of methanol and Pt nanoparticles as cocatalyst. The feasible photocatalytic process as well as the enhanced photogenerated charge separation have also been thoroughly studied.