Yang Y, Zheng Z, Yang M, Chen J, Li C, Zhang C, Zhang X. In-situ fabrication of a spherical-shaped Zn-Al hydrotalcite with BiOCl and study on its enhanced photocatalytic mechanism for perfluorooctanoic acid removal performed with a response surface methodology.
J Hazard Mater 2020;
399:123070. [PMID:
32540708 DOI:
10.1016/j.jhazmat.2020.123070]
[Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 05/11/2020] [Accepted: 05/26/2020] [Indexed: 05/08/2023]
Abstract
Perfluorooctanoic acid (PFOA), a widely used compound, is harmful to the environment and human health. In this study, a facile one pot solvothermal method of integrating BiOCl with Zn-Al hydrotalcite to form spherical-shaped BiOCl/Zn-Al hydrotalcite (B-BHZA) sample is reported. The characteristics and main factors affecting photocatalytic PFOA and photocatalytic mechanism of BiOCl/Zn-Al hydrotalcite (B-BHZA) are systematically investigated. It is found that spherical-shaped B-BHZA possesses abundant defects and a larger surface area of 64.4 m2 g-1. The factors affecting photocatalytic removal PFOA (e.g., time, pH, initial concentration and dosage) are investigated by modeling the 3D surface response. The removal rate of PFOA is over 90 % in 6 h under UV light at an optimal pH of 2, an initial concentration of 500 μg/L and a dose of dosage 0.5 g/L. The main mechanism occurs by photo-generated h+ oxidation and synergistic effects from the photocatalysis process. Though investigating the intermediates of PFOA degradation and F-, a possibility was proposed that h+ initiated the rapidly decarboxylation of PFOA. The unstable perfluoroheptyl group is formatted and further conversed to short chain perfluorocarboxylic acid. This study provides a new insight for the preparation of highly efficient photocatalysts to the treatment of halogenated compounds in UV system.
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