Lichen biomass for green synthesis of silver nanocolloids

Lichen is one of the most abundant non-vascular biomasses, however, a systematic study on application of the biomass in nanomaterial synthesis is very limited. In this study, aqueous lichen extract was obtained from Hypotrachyna cirrhata, one of the most abundant Himalayan Lichen biomass, following a simple cold percolation method. The effect of extract to silver nitrate mixing ratio, pH, and waiting time in growth and stability of nanoparticle was systematically explored. The rate constant for bio-reduction was found to be 5.3×10-3 min-1. Transmission electron microscopy (TEM) showed a narrow particle size distribution with mean particle size of 11.1±3.6 nm (n=200) The X-ray diffraction (XRD) and selected area electron diffraction (SAED) techniques confirmed the formation of cubic crystals. The synthesized colloidal solution showed excellent response for Hg2+ and Cu2+ ions in spiked water samples. The limit of detection and calibration sensitivity for Hg2+ and Cu2+ ions were found to b..., , , # Lichen biomass for green synthesis of silver nanocolloids

Figure 2A: UV-Vis spectra recorded at variable extract to silver nitrate volume ratio. The first column represents the wavelength (nm). The columns 2-6 represent absorbance measured with silver nitrate to lichen extract volume ratio of 1:1, 1:2, 1:3, 1:5, and 1:9; respectively. Columns 7 and 8 represent the wavelength (nm) and absorbance data for extract; respectively.

Figure 2D: FTIR data for the extract. The first column show the wavelength data (nm) and the second column transmittance.

Figure 3A: UV-Vis spectra measured at different waiting time. The first row show the wavelength (nm) and the other rows the absorbance at different waiting time.

Figure 4A: UV-Vis spectra measured at variable pH and waiting time of 24 hours. The first column show the wavelength data (nm) the other columns the corresponding absorbance measured at different pH.

Figure 4C: UV-Vis spectra measured at variable pH and waiting time of ...