Chitosan capped silver nanoparticles: Adsorption and photochemical activities
Zaheer Khan, Shaeel A. Al‐Thabaiti
Abstract
Chitosan capped silver nanoparticles (Chi-Ag) were prepared using AgNO3 and sodium borohydride. Chitosan was detected by using ninhydrin test, thermal gravimetric analysis and measurement of relative viscosity. Chi-Ag was used for removal of cadmium (Cd2+) at room temperature. The maximum monolayer adsorption capacity, and sorption intensity were estimated to be 119.04 mg/g and 1.6, respectively, from Langmuir and Freundlich adsorption isotherm models. The kinetics of Cd2+ adsorption onto Chi-Ag was proceeds through the pseudo-second-order kinetic model. Boyd and Elovich models suggest the adsorption and/or coordination of Cd2+ with the NH2 and OH groups of chitosan along with AgNPs proceeds through the film diffusion and chemisorption process. The average viscosity molecular weight of chitosan and Chi-Ag decreased with increased potassium persulfate (K2S2O8) and hydrogen peroxide (H2O2) concentration. The presence of H2O2 and K2S2O8 promoted the hydrolysis of chitosan due to the cleavage of glycosidic bond by generated HO and SO4− radicals.