Simple Synthesis of Gold Nanoparticles (AuNPs) from Gold Leaf by Electrolysis

The combination of nanotechnology and chemical education provides new avenues and exciting activities for students. With the easily accessible resources and facile synthetic approach of electrolysis, we report herein a comprehensive hands-on experiment of synthesizing gold nanoparticles (AuNPs) from gold leaf in classrooms. The provided guidelines permit teachers and students to perform laboratory activities for the synthesis of nanoparticles and learn the interactions between nanoparticles and light. AuNPs were synthesized in an aqueous solution containing sodium chloride (NaCl) as an electrolyte, glucose (C₆H₁₂O₆) as a reducing agent, and polyvinylpyrrolidone (PVP) as a stabilizing agent. During the COVID pandemic, this experiment was modified to allow students to perform it at home. The electrolytic solution was replaced with jelly without the addition of extra stabilizing agents or reducing agents. Moreover, the power supply was replaced by a 9-V battery. The gold nanoparticles were successfully synthesized but with a larger size. This experiment is valuable and effective, and the findings can be discussed in the context of learning about nanoparticle synthesis and their optical characteristics, which can be applied to high school and undergraduate students under supervision in classroom learning and remote education.