Investigation into the role of poly(vinylpyrrolidone) in the growth of high aspect ratio silver nanowires

The modified polyol method for the production of high aspect ratio silver nanowires (AgNWs) has received significant attention from many researchers due to its convenience and simplicity. Poly(vinylpyrrolidone) (PVP) is generally used as a template and capping agent in this method to stabilize the nanowires. However, the influence of different PVP molecules on the growth mechanism of AgNWs is not well understood. Given this, we designed a series of orthogonal experiments to obtain nanowires with an aspect ratio of 2500 and investigated the influence of PVP on the growing process leading to AgNWs. According to the results and previous studies, we proposed that relatively long PVP chains are apt to bond strongly with Ag atoms through their numerous carbonyl groups and thus promote the formation of long AgNWs. While promoting the growth in the AgNW's length, this mechanism of action restricts the growth of the diameter, thus leading to the formation of thin AgNWs with high aspect ratios as the final products.