Structural, optical, and mechanistic insights into enhanced visible-light degradation of tetracycline using Z-scheme zinc oxide/polyimide heterojunction photocatalysts

• Published in: Journal of Materials Science: Materials in Electronics
• Main Author: Guo M.; Li H.; Lim Y.C.
• Format: Article
• Language: English
• Published: Springer 2025
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85218197355&doi=10.1007%2fs10854-025-14320-1&partnerID=40&md5=6d5864c53f2733ee45209f5735923dc3

One of most efficient approaches to the development of advanced sunlight-driven photocatalysts is the creation of a heterojunction interface. In this study, we developed a Z-scheme zinc oxide/polyimide heterojunction photocatalyst (ZnO/PI), featuring one-dimensional (1D) ZnO nanowires that were grown on two-dimensional (2D) PI nanosheets by a low-temperature solid-state reaction. The ZnO/PI photocatalyst was designed to degrade tetracycline under simulated sunlight. The influence of the ZnO to PI mass ratio on the crystal structure, morphology, optical properties, and photoelectrochemical activity was analyzed using XRD, FESEM, HRTEM, UVDRS, BET, XPS, PL, and EIS. The FESEM analysis revealed a morphology transition from block-like structures to 2D sheet-like arrangement for PI upon compositing with ZnO. The optical property investigation showed pronounced light absorption in the visible region after growing ZnO on 2D PI. The 1:1 ZnO/PI showed significantly greater photocatalytic activity due to its strong light harvesting and photogenerated carrier separation efficiency, as well as synergistic interactions within the heterojunction as evidenced from HRTEM, EIS, and PL analysis. In addition, the ZnO/PI catalyst demonstrated consistent photocatalytic degradation efficiency over all four cycles. We proposed a Z-scheme carrier transfer pathway mechanism for the ZnO/PI. This study emphasizes on the connection between composition and photocatalytic performance, contributing to the current understanding of heterojunction photocatalysts as well as the potential applications of these materials in environmental remediation. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.