Synthesis of silver nanoparticles by radiolysis, photolysis and chemical reduction of AgNO₃ in Hibiscus sabdariffa infusion (karkade)

Silver nanoparticles of different average diameters were synthesized by γ-radiolysis, UV-photolysis and chemical reduction of AgNO₃ solutions in Hibiscus sabdariffa infusion commonly known as 'karkade'. The UV-photolysis was performed either by using a conventional Hg low pressure lamp emitting at 254 nm and also by using a new compact UV-LED source emitting at 360 nm. The kinetics rate constant of silver nanoparticles synthesis produced by γ-radiolysis and UV photolysis were determined and the average diameter of the resulting nanoparticles was estimated. (author)