Defect-mediated Z-scheme carriers’ dynamics of C-ZnO/A-CN toward highly enhanced photocatalytic TC degradation

Constructing Z-scheme photocatalysts is a promising strategy to improve the photocatalytic performance of materials, wherein carriers’ recombination plays a critical role by tuning carrier transportation and separation. In this study, a defect mediated layered heterojunction of amorphous carbon nitride (A-CN) and carbon doped ZnO (C-ZnO) are designed by calcination of ZIF-8 immersed urea. TEM and SEM elucidate the 2D heterojunctions coupled C-ZnO with a sheet-like A-CN that was formed. FTIR and XPS confirm the existence NCN and NCN groups interacted with C-ZnO. The defect-mediated C-ZnO/A-CN with 75% A-CN exhibited the highest tetracycline hydrochloride (TC) degradation rate, ~7.7, 3.0 and 7.7 times that of ZnO, loaded ZnO+CN or CN, respectively. Transient PL and photochemical characterizations revealed that defects assisted carriers’ recombination leads to a strong Z-scheme interfacial charge transfer and more reactive centers for TC degradation. This work would provide a new insight for the design of Z-scheme photocatalysts for the removal of pollutants.