Construction of Cu7s4@Cuco2o4 Yolk-Shell Microspheres Composite and Elucidation of its Enhanced Photocatalytic Activity, Mechanism, and Pathway for Carbamazepine Degradation

Water pollution caused by the massive use of medicines has caused major environmental problems. This work first reported the synthesis and characterization of the Cu7S4/CuCo2O4 (CS/CCO) yolk-shell microspheres via hydrothermal and annealing methods, then investigated their photocatalytic performance in removing organic water pollutants. The 10-CS/CCO composite with yolk-shell microspheres exhibited the highest photodegradation rate of carbamazepine (CBZ), reaching 96.3% within 2 h. The 10-CS/CCO also demonstrated more than 2 times higher photodegradation rates than the pure (Cu7S4) CS and (CuCo2O4) CCO. This outstanding photocatalytic performance can be attributed to the unique yolk-shell structure and the Z-scheme charge transfer pathway, reducing multiple reflections of the acting light. These factors enhanced the light absorption efficiency and efficiently transferred photoexcited charge carriers. In-depth photocatalytic degradation pathways of CBZ were systematically evaluated via the identification of degradation intermediates with Fukui index calculation.