Seed-mediated gold nanoparticle synthesis via photochemical reaction of benzoquinone

In this study, the synthesis of gold nanoparticles via a three-step reaction including a two-step photochemical reaction of 1,4-benzoquinone was demonstrated. The nanoparticles were formed by adding new gold ions to a solution containing seed nanoparticles pre-synthesized with hydroquinone and its oxidized form, 1,4-benzoquinone, by irradiating the solution with visible light. The diameter of the formed nanoparticles depended on the concentration of seed particles, with a higher seed particle concentration yielding smaller nanoparticles. The gold nanoparticles were characterized using UV-visible spectroscopy, transmission and scanning electron microscopy, and dynamic light scattering. Additionally, the synthesis of gold nanoparticles via photoreduction by benzoquinone is suggested to be a two-electron reduction reaction based on the photochemistry of benzoquinone and the pH change of the solution before and after irradiation.