In-situ Green Synthesis of Gold Nanoparticles using Unbleached Kraft Pulp

Abstract

Facile green synthesis of gold nanoparticles (AuNPs) on cellulose fiber was successfully achieved by reducing chloroauric acid (HAuCl4·3H2O) by means of unbleached kraft pulp. A significant color change in pulp fiber indicating the in-situ formation of gold was observed with one-step synthesis in an autoclave. As-prepared AuNP-cellulose fiber nanocomposites were thoroughly characterized by UV-Vis diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Gold nanoparticles were uniformly dispersed on the surface of the fiber by the bio-reduction of Au 3+ from metal salt to Au 0 with the α-carbonyl group and conjugated carbonyl of phenolic groups of lignin. The AuNPs formed on cellulose fibers were estimated to have average sizes of approximately 12.5, 12.4, 16.4, and 21.0 nm, depending on the concentration of Au 3+ involved in the synthesis.

Cellulose Fibers for High-Performance Textiles Functionalized with Incorporated Gold and Silver Nanoparticles

“…The current state of the art mainly involves four technologies to combine cellulose and noble metal nanoparticles. Among them, electrostatic assembly (Dong & Hinestroza 2009;Yu et al 2018;Tang et al 2012), seed mediated synthesis followed by dip coating (Zheng et al 2013), insitu reduction (Tang et al 2014;Tang et al 2015a;Boufi et al 2011;Bumbudsanpharoke & Ko 2015;Cai et al 2009), and the incorporation of nanoparticles via dry-jet wet spinning (Chen et al 2015;Kulpinski 2007;Rac-Rumijowska et al 2017;Smiechowicz et al 2011;Smiechowicz et al 2018;Smiechowicz et al 2014;Wendler et al 2008).…”

“…In a hydrothermal environment, cellulosic components can reduce metal ions to their elementary form, by using the terminal reducing end groups of cellulose. It has been argued about whether residual lignin plays a key role in this type of reaction as its hemiacetal and aldehyde groups are supposed to simultaneously reduce and stabilize the nanoparticles (Bumbudsanpharoke & Ko 2015). Other studies have highlighted the importance of sulphur and nitrogen containing units as they can provide additional binding centers for the metal ions during synthesis (Johnston & Nilsson 2012).…”

“…To synthesize AgAu nanoparticles, a combination of AgNO3 and HAuCl4 (0.03 ml/g, 50mM, respectively) was added. The resulting samples were transferred to an oven (135°C) to generate noble metal nanoparticles (Bumbudsanpharoke & Ko 2015). The efficiency of the reaction was estimated by the progressing color change from white to yellow (Ag: 15h), or white to purple (Au: 2h and AgAu: 2h).…”

“…The synthesis procedure of gold and silver nanoparticles followed a hydrothermal method reported by Bumbudsanpharoke et al, where diluted, aqueous solutions of HAuCl4 were applied on wet, unbleached kraft pulp to form nanometal particles (121°C, 101.35 kPa, 30 min) (Bumbudsanpharoke & Ko 2015). Under adequate conditions, cellulose can stabilize metal ions to convert them to their reduced form using its half acetal groups on the anomeric carbon (Boufi et al 2011;Bumbudsanpharoke & Ko 2015). Several studies also indicated that reduction reactions of this type are governed by an appropriate pH (Tang et al 2015b), and the presence of lignin (Bumbudsanpharoke & Ko 2015).…”

“…Under adequate conditions, cellulose can stabilize metal ions to convert them to their reduced form using its half acetal groups on the anomeric carbon (Boufi et al 2011;Bumbudsanpharoke & Ko 2015). Several studies also indicated that reduction reactions of this type are governed by an appropriate pH (Tang et al 2015b), and the presence of lignin (Bumbudsanpharoke & Ko 2015).…”