Salt-mediated polyol synthesis of silver nanowires in a continuous-flow tubular reactor

Abstract

This study is the first time for presentation of the synthesis of silver nanowires by a polyol reduction method in a continuous-flow reactor. The effects of process parameters on the conversion, selectivity, and morphology of silver nanowires are analyzed. Experimental results reveal that sufficient space time, low reaction temperature, and a moderate molar ratio of polyvinylpyrrolidone (PVP) to silver ions can result in high conversion (97.16%) and selectivity (near 100%). Normally, in our system the yield can reach 2 g h⁻¹ and the resulting AgNWs have an average length of 22 μm and diameter of 90 nm. It is found that the length of the AgNWs can be adjusted by varying the initial concentration of silver ions and the PVP amount, and the diameter can be reduced with increasing concentration of potassium chloride. Unlike the batch system, it doesn't hinder the growth of silver nanowires that all of the reactants are added simultaneously into the reactor for the continuous-flow system, resulting from the formation of pre-seeds and the rapid rise of temperature in the tubular reactor.