1. Bifunctional photocatalytic nanofiltration membranes with immobilized BaTiO3/Ti3C2Tx catalysts for the simultaneous separation and degradation of azo compounds.
- Author
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Zheng, Huiqi, Meng, Xiaorong, Yang, Yingzi, Chen, Jin, and Huo, Shanshan
- Subjects
AZO compounds ,COMPOSITE membranes (Chemistry) ,POLYVINYLIDENE fluoride ,NANOFILTRATION ,PHOTODEGRADATION ,DIMETHYLAMINOAZOBENZENE ,RADICALS (Chemistry) - Abstract
Bifunctional photocatalytic nanofiltration (NF) membranes are becoming increasingly popular because of their ability to separate and degrade azo compounds (azos) in water. However, several serious drawbacks limit their practical implementation. In this study, a polyamide (PA) layer formed by interfacial polymerization on the polyvinylidene fluoride membrane surface and polydopamine (PDA) were combined with BaTiO 3 /Ti 3 C 2 T x (BT) nanoparticles to prepare photocatalytic BT@PDA (BTPP) membranes, which integrated physical separation and photocatalytic degradation into a single process. By optimizing synthesis conditions, a BTPP membrane with high water permeability (34.0 L·m
–2 ·h–1 ·bar–1 ) and Na 2 SO 4 rejection rate (94.7%) was produced. The photocatalytic activity of this membrane was examined by studying the photocatalytic degradation efficiency of several azos. After 180 min of irradiation with a 300 W Xe lamp (λ ≥ 420 nm), the degradation rate of methyl orange (MO) reached 95.3%, while the degradation rates of alizarin yellow GG and methyl red were 92.7% and 83.5%, respectively. The photocatalytic performance of the BTPP membranes for azos degradation was verified by studying the charge transfer process and generation of reactive radical species (·OH and·O 2– ), and possible structures of the main intermediates formed during MO degradation were identified. This work provides new insights into the synthesis and degradation properties of bifunctional photocatalytic NF membranes. [Display omitted] • BaTiO 3 /Ti 3 C2T x (BT) structure with good photocatalytic properties. • Bifunctional photocatalytic BT@dopamine (BTPP) membranes with excellent performance is proposed. • BTPP membranes promote the simultaneous separation and photodegradation of azo compounds. • The degradation of azo compounds by BTPP membranes include ·OH and ·O 2– active radicals. [ABSTRACT FROM AUTHOR]- Published
- 2023
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