Preparation of Cu2O/ g-C3N4-modified TiO2 composite catalysts by a two-step method: degradation of RhB in sunlight

To deal with water pollution, photocatalytic degradation has become a more prominent technology in this field. In this paper, Cu2O and g-C3N4 were added to TiO2 by calcination and coupling, which greatly improved the catalytic efficiency of titanium dioxide. Using the smaller band gap of Cu2O and g-C3N4, the corresponding sunlight can be greatly increased, making up for the shortcomings of TiO2 which can only respond to ultraviolet light. Rhodamine B was used to simulate organic pollutants. RhB can be oxidized directly by photogenic holes and center dot OH radicals. Moreover, heterojunction can be formed between Cu2O, TiO2, and g-C3N4, which further promotes the spatial separation of photoelectron-hole pairs generated by the formation of internal electric fields. Compared with pure TiO2, the efficiency is increased by 2.5x. This study provides an effective way to improve the photocatalytic performance of TiO2 and provides a new idea for organic dye treatment and environmental remediation.