Bifunctional Regenerated Cellulose/Polyaniline/Nanosilver Fibers as a Ccatalyst/Bactericide for Water Decontamination

　　Water sources bear the brunt of adverse effects, which are occupied by massive pollutants, including chemicals and bacteria. Considering that nearly 800 million people currently still lack access to a water purification device and the grave threat of contaminated water to human health, accumulation of chemicals and bacteria contaminated issues in water concern the public increasingly. More seriously, the antibiotics abuse brought the emergence of pathogenic bacterial resistance to antibiotics, which requires new disinfection systems and disposal systems for water purification.

　　Silver nanoparticles (Ag NPs) exhibited a substantial antibacterial property against broad-spectrum bacteria and presented very little systemic toxicity toward humans. It has become a hot research topic due to their peculiar catalysis and high activity against a broad range of microbes and hazardous substances. However, the nanoparticles tend to self-aggregate, resulting in a limited sufficient load and a significant decrease in their antibacterial activity. On the other hand, it is difficult to separate the nanoparticles from the catalytic system by filtration or centrifugation, resulting in incredibly limited reusability and economic severity.

　　Institute of Bioengineering, Guangdong Academy of Science, together with School of Textile Materials and Engineering, Wuyi University designed a green route to fabricate regenerated cellulose fibers (CFs) with 3D micro- and nanoporous structures in NaOH/urea aqueous solvent systems via a scalable wet-spinning procedure as support materials for Ag NPs. Modification of CFs with polyaniline@Ag nanocomposites through in situ reduction of the silver ion with aqueous aniline led to enhanced pollutant removal efficiency of functional cellulose-based fibers (FCFs), demonstrating both rapid hydrogenation catalytic performance for the reduction of p-nitrophenol and high antibacterial properties for in-flow water purification. Most importantly, the hierarchically porous structures of FCFs not only provided carrier space but also formed a limiting domain guaranteeing the homogeneity of FCFs even with a Ag NP content as high as 36.47 wt%. The prepared functional fibers show good behavior in in-flow water purification, representing significant advancement in the use of biomass fibers for catalytic and bactericidal applications in liquid media.

　　Related research results have been published in ACS Applied Materials&Interferences.

　　This work was supported by the Science Foundation for High-Level Talents of Wuyi University, Guangdong Basic and Applied Basic Research Foundation, Foundation of Department of Education Guangdong Province, Jiangmen Basic and Theoretical Scientific Research Project, Wuyi University-Hong Kong Joint Research Fund, the National Natural Science Foundation of China, and GDAS’ Project of Science and Technology Development.

　　Related links：https://pubs.acs.org/doi/10.1021/acsami.0c20188

　　Figure 1. Water decontamination application of the functional cellulose fibers. (a-f) Catalytic behavior of the toxic compound, p-aminophenol, in water, including the reaction scheme of p-aminophenol from p-nitrophenol with FCFs (a), photographs showing the reduction of p-nitrophenol in 50 s using a bundle of FCFs (b), variation in UV-vis absorption spectra during the catalytic reduction and color change from bright yellow to colorless in the inset (c), the curves of C/C0 (d) and ln(C/C0) (e) as a function of the reduction reaction time for CFs and three types of FCFs, and the catalytic activity of FCFs-II during the cycling use (f). Antibacterial performances of the functional fibers on E. coli-contaminated water through (g).