Growth Factors for Silver Nanoplates Formed in a Simple Solvothermal Process

Abstract

We synthesized both big and ultra-small silver nanoplates through a simple solvothermal process in a common autoclave. Using this approach, we achieved the reduction of silver nitrate in DMF or ethanol in the presence of PVP as a capping agent. The reduction capacity of PVP was also investigated. Growth factors such as the concentration of silver precursor, quantity of capping agent, reaction time, and temperature have been shown to play important roles in the formation of different sizes and shapes of silver nanoplates. The big plates, over 100 nm in edge length, were found mainly in the shape of a connected triangular. Single triangle plates, truncated triangular plates, and hexangular plates were also found under different reaction conditions. The ultra-small silver nanoplates, 20-100 nm in edge length, were successfully extracted from the solution under different centrifugation conditions. The UV-vis spectrum exhibited intense in-plane dipole absorption peaks varying from 470-630 nm, as reflected by the gradual color change of the solution from orange to red, and finally to blue.