The role of an ultra-thin carbon layer in enhancing solar water-splitting performance of Z-scheme ZnO@MOF-5/C photoanodes
Colloids and Surfaces A: Physicochemical and Engineering Aspects, vol.720, 2025 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 720
- Publication Date: 2025
- Doi Number: 10.1016/j.colsurfa.2025.137112
- Journal Name: Colloids and Surfaces A: Physicochemical and Engineering Aspects
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Biotechnology Research Abstracts, Chemical Abstracts Core, Chimica, Compendex, EMBASE, INSPEC
- Keywords: Carbon layer, MOF-5, Photoelectrochemical water splitting, Z-scheme heterostructure, ZnO
- Ankara Yıldırım Beyazıt University Affiliated: Yes
Abstract
In this study, we successfully synthesized core-shell ZnO@MOF-5/C ternary heterostructures as visible light-responsive photocatalysts for highly efficient photoelectrochemical (PEC) water splitting. A bioinspired polydopamine (PDA) shell was calcined to form a conductive N-doped graphitic carbon layer on ZnO@MOF-5, preserving its star-shaped morphology while significantly enhancing electron transport. As a result, the ZnO@MOF-5/C photoanode achieved an impressive photocurrent density of 3.41 mA/cm² at 2.50 V vs. RHE under Xenon (Xe) illumination, surpassing pristine ZnO by 3.35 times and dark-state ZnO@MOF-5/C by 12.5 times. This enhancement is attributed to the efficient separation and transfer of photogenerated charge carriers. Additionally, the ZnO@MOF-5/C system exhibited a notable incident photon-to-current conversion efficiency (IPCE) of 24 % at 490 nm, highlighting its superior light-harvesting capability. To elucidate the underlying charge transfer mechanism, radical scavenging experiments and X-ray photoelectron spectroscopy (XPS) confirmed a Z-scheme charge separation pathway. These findings introduce a novel semiconductor-MOF heterojunction design with exceptional visible-light sensitivity, paving the way for advanced PEC applications.