Scalable solvo-plasma production of porous tin oxide nanowires

Abstract

This paper reports a fast, scalable method for synthesizing tin oxide nanowire powder using cheap starting material of commercial tin oxide particles and an atmospheric microwave plasma reactor. Specifically, the synthesis concept involves plasma oxidation of tin oxide powder combined with potassium hydroxide for few seconds to a minute which is orders of magnitude lower than that using hydrothermal or vapor–liquid–solid (VLS) techniques. Even at lab scale, large-scale production of tin oxide nanowire powder as high as 10g per hour has been produced. Systematic studies reveal nucleation and growth of K2SnO3 nanowires from molten alloy involving KOH and tin oxide. A simple annealing step is used to convert K2SnO3 intermediate nanowires into pure tin oxide nanowires. The extremely short reaction time of 20s is three orders of magnitude faster than that of traditional hydrothermal method. It was shown that our tin oxide nanowire powder shows a high reversible capacity of 848mAhg−1 after 55 cycles at a current density of 100mAg−1. The scalable production technique presented here and the applicability of resulting tin oxide nanowire powders makes it as suitable for practical implementation into lithium-ion battery applications.