An XAS study of the binding and reduction of Au(III) by hop biomass

摘要: Previous studies have shown that hop biomass is capable of adsorbing significant amounts Au(III) from aqueous solutions. Hop was chemically modified to determine the contributions different functional groups on binding and reduction Au(III). Previously, performed batch showed fast, occurring within first 5 min contact in a pH dependent manner. However, esterified behaved independent manner found not change with changing pH. hydrolyzed had similar native hops biomass, showing trend. X-ray absorption spectroscopy (XAS) analysis, XANES (X-ray near edge structure), EXAFS (extended fine structure) were used oxidation state, coordination environment, average radii gold nanoparticles bound biomass. The XAS data confirmed presence Au(0) both biomasses. fittings show reduced by approximately 81%, 70%, 83% native, esterified, respectively. In addition, calculation particle radius also agreement results previously transmission electron microscopy studies. could only be calculated for which 17.3 A 9.2 A,