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

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 m(2) g(-1), respectively, whereas that of the untreated chitosan fibers is 0.1 m(2) 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.