2025/07/06 by Intaphong, Prakasit, Inphak, Pasu, Tandorn, Sujitra +2
#Cu-based composite #Cu-thiourea #Heterojunction #Photocatalytic activity #Thermal decomposition
paper · doi:10.57647/j.ijc.2025.1503.28
The novel quaternary heterojunction copper sulfide/cuprous sulfide/cuprous oxide/carbon nitride (CuS/Cu9S5/Cu2O/C3N4) composite was prepared by thermal decomposition. The phase, composition, morphologies, and oxidation state of elements in as-prepared heterojunction multiphase Cu-based composites were characterized and discussed in this research. The XRD, SEM, and TEM analyses showed the binary CuS/Cu9S5 composite at 400-450 oC and quaternary heterojunction CuS/Cu9S5/Cu2O/C3N4 composite at 500-600 oC, which presented the mixed irregular sheets and agglomerated particles in shape. The photocatalytic activities of heterojunction multiphase Cu-based composites were studied by methyl orange (MO) degradation under visible light irradiation. It was found that the CuS/Cu9S5/Cu2O/C3N4 composite at 600 °C showed the highest photodegradation efficiencies of MO at 90.06% under visible light irradiation within 150 min due to the charge diffusion at the CuS/Cu9S5/Cu2O/C3N4 interface. The active species for MO degradation over CuS/Cu9S5/Cu2O/C3N4 composite were analyzed by scavenger test, which reveals that the ●O2- radicals and h+ are the main and minor active species for MO degradation photocatalyzed by the CuS/Cu9S5/Cu2O/C3N4 composite under visible light irradiation. Finally, the photodegradation efficiency of MO in the presence of the CuS/Cu9S5/Cu2O/C3N4 composite at 600°C decreased by 85.89% after five cycles, demonstrating its high stability and reusability for practical photocatalytic applications.