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 -N-C equivalent to N and -N=C=Ne groups interacted with C-ZnO. The defect-mediated C-ZnO/A-CN with 75% A-CN exhibited the highest tetracycline hydrochloride (TC) degradation rate, similar to 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. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

Constructing Z-scheme photocatalysts through defect mediated layered heterojunction of amorphous carbon nitride and carbon doped ZnO shows improved photocatalytic performance with higher degradation rates and more reactive centers for pollutants removal, providing new insights for the design of efficient photocatalysts.