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

• Published in: Journal of alloys and compounds Vol. 877; p. 160321
• Main Authors: Huang, Xiaoyan, Zhang, Xiuyun, Zhang, Kexiang, Xue, Xiaogang, Xiong, Jian, Huang, Yu, Zhang, Doudou, Zhang, Jian, Zhang, Zheling, Yan, Fengpo
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 05-10-2021; Elsevier BV
• Subjects: Amorphous materials; Carbon; Carbon nitride; Charge transfer; Defect mediated Z-scheme; Heterojunctions; Interfacial interaction; Photocatalysis; Photocatalysts; Photocatalytic TC degradation; Photodegradation; Pollutants; Synergistic effect; Zinc oxide; Photocatalytic TC degradation; Defect mediated Z-scheme; Synergistic effect; Interfacial interaction
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2021.160321

•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.
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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.