Peroxymonosulfate-assisted photocatalytic degradation of sulfadiazine using self-assembled multi-layered CoAl-LDH/g-C3N4 heterostructures: Performance, mechanism and eco-toxicity evaluation. (February 2020)

• Record Type: Journal Article
• Authors: Zeng, Hanxuan; Zhang, Haojie; Deng, Lin; Shi, Zhou
• Is Part Of: Journal of water process engineering. Volume 33(2020)
• Publication Date: 2020-02
• Subjects: Multi-layered -- LDH -- g-C3N4 -- Peroxymonosulfate -- Sulfadiazine degradation; Water-supply engineering -- Periodicals; Saline water conversion -- Periodicals; Seawater -- Distillation -- Periodicals; Sanitary engineering -- Periodicals; Sewage -- Purification -- Periodicals; 627
• DOI: 10.1016/j.jwpe.2019.101084
• Languages: English
• ISSNs: 2214-7144

Abstract

Highlights: Multi-layered CoAl-LDH/g-C3 N4 heterostructures was synthesized using exfoliated CoAl-LDH and g-C3 N4 nanosheets. CoAl-LDH/g-C3 N4 was firstly used to activate PMS for sulfadiazine degradation. CoAl-LDH in the heterostructures activated PMS to produce SO4 – and OH. g-C3 N4 acted as dual roles: electron acceptor and PMS activator. The catalytic mechanism was proposed. Abstract: CoAl-LDH/g-C3 N4 (CoAl-LDH/CN) heterostructures was prepared through self-assembly method using exfoliated CoAl-LDH and g-C3 N4 nanosheets via electrostatic attraction force. The morphology and physicochemical properties characterization verified the success synthesis of layer-by-layer structure of CoAl-LDH/CN. Heterogeneous catalytic degradation of sulfadiazine (SDZ) was assessed using CoAl-LDH/CN combined with peroxymonosulfate (PMS) and visible light irradiation. A remarkable synergistic effect was obtained in SDZ removal. After 15 min, 10 μM SDZ could be removed by 87.1 % at conditions of 0.1 g/L CoAl-LDH/CN, 0.5 mM PMS, and pH = 6.0. The reusability tests signified the excellent reusing potential of CoAl-LDH/CN. Mechanism study suggested that CoAl-LDH in the heterostructures activated PMS to produce SO4 – and OH, while g-C3 N4 acted as dual roles: electron acceptor and PMS activator. Additionally, density functional theory (DFT) calculations successfully disclosed that the sites with high Fukin index ( f 0 ) on SDZ molecule were more vulnerable to radicals attack. Eco-toxicity evaluation signified the generation of less toxic intermediates compared to SDZ after photocatalysis. Our findings demonstrate the integration of CoAl-LDH/CN, visible light and PMS can be applied as a promising approach for efficient degradation of organic compound polluted water.