In situ self-cleaning removal of emerging organic contaminants with covalent organic framework armed with arylbiguanide

Ruifang Qi; Jinming Lei; Lili Dong; Sadam Hussain Tumrani; Chenghong Feng

doi:10.1016/j.jhazmat.2024.137073

In situ self-cleaning removal of emerging organic contaminants with covalent organic framework armed with arylbiguanide

J Hazard Mater. 2025 Jan 3:486:137073. doi: 10.1016/j.jhazmat.2024.137073. Online ahead of print.

Authors

Ruifang Qi¹, Jinming Lei², Lili Dong³, Sadam Hussain Tumrani⁴, Chenghong Feng⁵

Affiliations

¹ State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China; College of Chemical Engineering and Biological Technology, Xingtai University, Xingtai 054001, PR China.
² State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China; The Key Laboratory of Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing 100875, PR China.
³ College of Chemical Engineering and Biological Technology, Xingtai University, Xingtai 054001, PR China.
⁴ State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China.
⁵ State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China; The Key Laboratory of Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing 100875, PR China. Electronic address: fengchenghong@bnu.edu.cn.

PMID: 39787853
DOI: 10.1016/j.jhazmat.2024.137073

Abstract

An in situ self-cleaning covalent organic framework featuring arylbiguanide arms (Aryl-BIG-COF) was first developed to remove emerging organic pollutants such as propranolol (PRO) from water. The main breakthroughs addressed the scarcity of functional active sites, the impracticality of ex situ regeneration, and the rapid recombination of electronhole pairs in the application of COFs. Owing to the directional capture ability and electronic structure regulation of the arylbiguanide arms, the adsorption capacity and photocatalytic degradation rate of the newly synthesized COF increased by nearly four and seven times, respectively. Its self-cleaning ability, driven by the photocatalytic regeneration of active sites, enabled in situ removal of PRO and sustained over 90 % removal efficiency after six cycles. Moreover, it demonstrated broad applicability for removing PRO and other emerging pollutants, such as bisphenol A (BPA), tetracycline (TC), and norfloxacin (NOR), across various water matrices with less residual toxicity. The coexisting organic matter and ions in natural water promoted the removal of PRO. The enhancement mechanism involved arylbiguanide arms narrowing the band gap and inducing local charge polarization, thereby increasing the separation efficiency of electronhole pairs. This work provides significant insights into the structural design and practical applications of COFs for purifying water.

Keywords: Arylbiguanides; Covalent organic frameworks; Emerging contaminants; Photocatalysis; Self-cleaning.