Photocatalytic activity and antibacterial properties of linen fabric using reduced graphene oxide/silver nanocomposite

Abstract

Silver nanoparticles were in situ prepared on the surface of linen fabric coated by graphene oxide (GO). In the meantime, the reduction of silver nitrate on the GO-coated fabric led to the synthesis of reduced graphene oxide on the fabric. Two kinds of substrate (cotton and linen) were used. Both RGO/Ag and Ag/GO nanocomposites were added on cotton and linen fabrics through a conventional "pad-dry-cure" method. The chemistry and morphology of the coated surfaces were extensively characterized using Fourier-transformed infrared spectroscopy, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. Resistivity measurements were used for assessing the conductivity. The UV protection properties and the photocatalytic activity of the coated fabrics against methylene blue dye were also investigated. The antibacterial activity was studied against Gram-positive S. aureus and B. subtilis and Gram-negative bacterial strains E. coli and P. aeruginosa by determining the zone of inhibition using the agar diffusion method. Methicillin-resistant Staphylococcus aureus (MRSA) has been responsible for many serious hospital infections worldwide. The fabrics showed superior antibacterial activity and successfully hindered the growth of pathogenic bacterial strains. This outcome suggested that both the RGO/Ag and Ag/GO nanocomposites-coated fabrics could be potentially applied in biomaterials and biomedical fields.

Fig. 1. Schematic mechanism for the coating process of cellulosic fabrics: (a) illustration of the coating process and (b) chemical mechanism for the coating process.

Fig. 2. FTIR spectra of the treated fabrics. (a) Spectra for: blank cotton (B-cotton), GO–cotton (C–GO), and RGO–Ag cotton (C–RGO–Ag). (b) Spectra for: blank linen (B-linen), GO–linen (L–GO) and RGO–Ag linen (L–RGO–Ag).

Fig. 3. SEM images of the coated cotton and linen samples: (a, b and c) SEM images for the uncoated, GO-, and RGO/Ag-coated cotton samples; (d, e and f) SEM images for the for uncoated, GO-, and RGO/Ag-coated linen fabrics.

Fig. 4. EDX analysis of the coated cotton and linen samples: (a and b) EDX for cotton coated with GO and RGO/Ag; (c and d) EDX for linen coated with GO and RGO/Ag.

Fig. 5. Digital photographs of the treated cotton and linen fabrics.

Fig. 6. UV-vis absorption spectra from the degradation of methylene blue (MB) under a normal laboratory environment. Photodegradation of MB-treated (A) cotton fabric with the time of exposure of 12 h: (a) MB/untreated cotton fabric, (b) MB/GO-coated cotton fabric, (c) MB/Ag nanoparticle-coated cotton fabric, (d) MB/Ag–GO-coated cotton fabric, and (e) MB/RGO–Ag-coated cotton fabric. Photodegradation of MB on the treated (B) linen fabric when the time of exposure was 12 h: (f) MB/untreated linen fabric, (i) MB/GO-coated linen fabric, (j) MB/Ag nanoparticles-coated linen fabric, (h) MB/Ag–GO-coated linen fabric, and (g) MB/fabric RGO–Ag-coated linen fabric.

Fig. 7. Electrical conductivity of the treated and untreated fabrics.

Fig. 8. TGA curves of the untreated, GO-coated, and RGO/Ag-coated: (a) cotton fabrics, (b) linen fabrics.