Multi-Functional Cu-BTC and ZIF-67 Grown Chitosan Air Filters for Efficient NO and Particular Matter Removal

Abstract

Zeolitic imidazolate framework-67 (ZIF67) or copper(II)-benzene-1,3,5-tricarboxylate (CuBTC)-based chitosan fibers grown in situ on fibers can be used in the development of effective air filters. In this context, herein, metal–organic frameworks (ZIF67 or CuBTC) are grown in situ on chitosan fibers (denoted as C-ZIF67 or C-CuBTC), and the NO gas adsorption performance, particular matter filtration efficiency, and antibacterial properties of the fabricated materials against E. coli and S. epidermidis are investigated. The specific surface areas of C-ZIF67 and C-CuBTC are 311.9 and 140.1 m2 g−1, respectively, whereas that of the untreated chitosan fibers is 0.1 m2 g−1. For C-ZIF67, the NO adsorption efficiency rapidly increases up to 78%; specifically, 70% adsorption is maintained for 65 min. For C-CuBTC, the NO adsorption efficiency rapidly increases up to 54% initially and substantially decreases to 41% after 10 min. Furthermore, C-ZIF67 exhibits a 3.4 times higher NO adsorption capacity than that of C-CuBTC. For C-ZIF67 and C-CuBTC, the filtration efficiencies against PMs are higher than 99%. However, C-CuBTC shows a higher antibacterial activity (99.99%) against E. coli and S. epidermidis compared to C-ZIF67. The C-ZIF67 and C-CuBTC, derived from renewable resources, can be good alternatives for commercial synthetic air filters because they are biodegradable, cost-effective, and environment-friendly.