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

•The defect-mediated Z-scheme of C-ZnO/A-CN was in-situ synthesized from porous ZIF-8/urea.•The photocatalyst exhibited high performance for the degradation of tetracycline hydrochloride antibiotics.•The rate constant of C-ZnO/A-CN with 75% A-CN improved by a factor of 7.7 and 7.7 compared to pure ZnO and CN.•The charge transfer pathway of the C-ZnO-CN photocatalyst was proposed. [Display omitted] 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.