Yashi Qing,Yanxiang Li,Lixia Cao,Yujie Yang,Li Han,Panchan Dansawad,Haigang Gao,Wangliang Li
17β-estradiol (E2) in natural water has caused serious environmental problems because of its extremely high estrogenic activity. Herein, a novel β-CD@PANI/BiOBr (C-PANI/BiOBr) step scheme (S-scheme) heterojunction photocatalyst was successfully prepared via facile chemical precipitation method. The encapsulation of β-cyclodextrin (β-CD) around polyaniline (PANI) contributed to better transfer of photogenerated carries by the stabilization of radical cation and excellent adsorption capability driven by hydrophobic interaction, hydrogen bonding and π-π stacking. The C-PANI/BiOBr heterojunction photocatalysts realized excellent light absorption in full spectrum. The N derived from C-PANI could coordinate with Bi metal ions, which favored forming BiOBr with (1 1 0) facet exposure, thus promoting the photogenerated electron-hole separation. The optimal 20% C-PANI/BiOBr achieved rapid degradation of contaminants (100% removal of E2 in 40 min and RhB in 9 min) under visible light irradiation. Furthermore, three main degradation pathways of E2 photodegradation were proposed by high performance liquid chromatography-mass spectrometer (HPLC-MS) results, and the toxicity of E2 and intermediates were evaluated by ECOSAR program. The active species capture experiment indicated that h + and •O 2 – played the dominated roles in the photodegradation process and S-scheme mechanism of C-PANI/BiOBr with enhanced photocatalytic performance was also revealed. This study provided an insight in fabricating efficient photocatalysts for environmental remediation.
Yashi Qing,Enming Huang,Lixia Cao,Haigang Gao,Shengyong Zhao,Yanxiang Li,Wangliang Li
The prevalence of 17β-estradiol (E2) in wastewater has attracted widespread attention due to the negative impacts on ecological environments and human health. Nowadays, photocatalysis has been emerged as an efficient technology for E2 containing wastewater treatment. However, traditional powder photocatalysts face challenges such as easy agglomeration, secondary pollution and difficult recovery, limiting their large-scale application. In this study, a photocatalytic PA/C-PANI@BiOBr membrane was fabricated by immobilizing polyaniline (PANI) layer and BiOBr nanosheets on polyamide (PA) membrane through in-situ chemical bath deposition. This process leveraged the strong hydrogen bond interaction between PANI and PA, with the fine PANI fibers providing nucleation sites for the in-situ growth of BiOBr nanosheets. By repeating the immersion process, we controlled variations in the coverage density and morphology of BiOBr on the membrane surface. The PA/C-PANI@BiOBr membrane exhibited outstanding light absorption and photocatalytic performance. Notably, the optimal PA/C-PANI@BiOBr-10 membrane achieved 100 % removal efficiency of 3 mg L −1 E2 within 40 min. In dynamic cyclic experiments, PA/C-PANI@BiOBr-10 membrane maintained stable permeability and high removal efficiency of pollutants. The photocatalytic mechanism underlying these results was elucidated through photoelectric testing and further photocatalytic experiments. Furthermore, the PA/C-PANI/BiOBr-10 membrane demonstrated remarkable durability over multiple consecutive cycles, with E2 removal efficiency remaining above 96.5 % after 5 cycles.