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Guo J, Fan Y, Dong X, Zeng H, Ma X, Fu Y. Study on preparation of UV-CDs/ Zeolite-4A/TiO 2 composite photocatalyst coupled with ultraviolet-irradiation and their application of photocatalytic degradation of dyes. J Environ Manage 2024; 354:120342. [PMID: 38382431 DOI: 10.1016/j.jenvman.2024.120342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 01/11/2024] [Accepted: 02/08/2024] [Indexed: 02/23/2024]
Abstract
In this work, ultraviolet irradiation was employed to assist in the preparation of a novel photocatalyst composite in the form of carbon dots/zeolite-4A/TiO2, using coal tailings as the source of silicon-aluminum and carbon. The composite was designed for the degradation of methylene blue under 500 W of UV light irradiation. Zeolite-4A was used as a support for the well-dispersed carbon dots and TiO2 nanoparticles. The as-prepared composites were subjected to thorough characterization, confirming the successful formation of zeolite-4A with a cube structure, along with the loading of TiO2 and coal-based CDs in the composites. The experimental results demonstrated that the UV-CZTs nanocomposites exhibited a remarkable removal efficiency of 90.63% within 90 min for MB. The corresponding rate constant was exceptionally high at 0.0331 min-1, surpassing that of the Dark-CZTs and pure TiO2. This significant enhancement was possibly due to the synergistic effect of adsorption photocatalysis of the UV-CZTs, combined with the excellent electron-accepting capabilities of the coal-based CDs, which led to highly improved charge separation. An investigation of the spent photocatalyst's recyclability revealed that it retained a remarkable 82.94% MB removal efficiency after five consecutive cycles, signifying the stability of the composite. Trapping experiments also elucidated the primary reactive species responsible for MB degradation, which were identified as photo-generated holes and ⸱O2- species. By this process, the hydroxyl radicals generated in the system successfully promoted the transformation of coal tailings to coal-based zeolite and coal-based CDs. Coal-based zeolite served as an excellent carrier of titanium dioxide, which improved its dispersibility. The inhibition of e--h+ recombination of titanium dioxide by introducing coal-based CDs improved the photocatalytic ability of titanium dioxide. Through this study, coal tailings, as a coal processing waste, were transformed into high-value materials, and relevant photocatalytic composite materials could be prepared with broad application prospects.
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Affiliation(s)
- Jiaqi Guo
- College of Mining Engineering, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, China; Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada
| | - Yuping Fan
- College of Mining Engineering, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, China
| | - Xianshu Dong
- College of Mining Engineering, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, China.
| | - Hongbo Zeng
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada.
| | - Xiaomin Ma
- College of Mining Engineering, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, China
| | - Yuanpeng Fu
- College of Mining Engineering, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, China
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