Metal Nanoparticle Harvesting by Continuous Rotating Electrodeposition and Separation

Current synthetic approaches to metal nanoparticles are mostly batch processes that use a large quantity of reagents and surfactants, producing enormous amount of solid and liquid waste. Here, we developed a rotating electrodeposition and separation (REDS) technique, which entails electrochemically depositing nanoparticles onto a continuously rotating metal foil and subsequently harvesting them through mechanical delamination. A wide array of elemental nanoparticles (e.g., Ag, Au, Ni, Cu), alloys nanoparticles (e.g., FeCoNi and FeCoNiW), and metal oxide nanomaterials (e.g., Co3O4) were synthesized by REDS. We further controlled the growth direction of metals during the electrodeposition to fabricate more complex structures such as polyhedrons, nanoplates, dendrites, and flower nanostructures. Based on the metallic nanoparticles, we obtained conducting inks and fabricated near-field communication tags and touch screen panels. Our technique provides a novel approach for rapid, scalable, and green preparation of low-cost and high-quality nanoparticles in which electrodeposition chemistry can be controlled with a roll-to-roll system.