Facile synthesis of multi-shelled AgI/ZnO composite as Z-scheme photocatalyst for efficient ciprofloxacin degradation and H2 production

• Published in: Journal of materials science. Materials in electronics Vol. 32; no. 22; pp. 26241 - 26257
• Main Authors: Wu, Xianghui, Zhang, Yuzhe, Wu, Huadong, Guo, Jia, Wu, Kun, Zhang, Linfeng
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.11.2021; Springer Nature B.V
• Subjects: Catalytic activity; Characterization and Evaluation of Materials; Chemical precipitation; Chemistry and Materials Science; Composite materials; Electromagnetic absorption; Electron transfer; Energy gap; Free radicals; Halides; Heterojunctions; Hydrogen evolution; Hydrogen production; Materials Science; Microspheres; Nanoparticles; Optical and Electronic Materials; Optimization; Photocatalysis; Photocatalysts; Photodegradation; Photoelectricity; Shells (structural forms); Silver halides; Structural analysis; Zinc oxide
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-021-06844-z

Overcoming defects through effective modification methods have become the main method for material performance optimization. In this paper, AgI nanoparticles were loaded on the hollow multi-shell ZnO microspheres through a chemical precipitation method, and the composites with a hollow multi-shell structure were successfully constructed. The formation of heterojunctions between these two semiconductors alleviates the photo-corrosion phenomenon for ZnO, and then the composite exhibits higher photocatalytic stability. On the other hand, the introduction of narrow band-gap AgI effectively reduces the optical band gap of ZnO. The photocatalytic performance of the composite was evaluated through the ciprofloxacin (CIP) photodegradation and H 2 evolution under simulated solar irradiation. The results show that when the ratio of AgI was controlled 7%, the AgI/ZnO composite shows the best CIP photodegradation performance with an apparent rate constant of 0.0463 min −1 (5.26 times as the rate of ZnO), and the photocatalytic H 2 production rate reaches 2.725 mmol/g/h. The structure and photoelectric property characterization indicate that the boost of the photocatalytic property for AgI/ZnO composites is major due to improve light absorption region, strengthen of e − /h + separation, and promotion of the electron transfer efficiency. Combined with free radical capture experiments and theoretical calculations, the possible catalytic mechanism of heterojunction catalysts is proposed. Moreover, this work provides a direction in building multi-shelled ZnO heterojunction photocatalysts with silver halides modification and investigating the mechanism of photocatalytic activity enhancement.