Constant-rate dissolution of InAs nanowires in radiolytic water observed by in situ liquid cell TEM.

Understanding the dissolution process and mechanism of materials in a liquid at the nanoscale is very important for both science and technology in many fields. Although the dissolution process of nanoparticles has been studied by many groups, the dissolution of one-dimensional (1D) nanomaterials with a high aspect ratio has seldom been directly observed with a high spatial resolution. In this paper, the dissolution process of 1D nanowires (NWs), InAs NWs as an example, in radiolytic water is studied by in situ liquid cell transmission electron microscopy. Different from most size-dependent dissolutions of nanoparticles, the dissolution rate of InAs NWs is found to be constant with reducing size down to ∼5 nm in diameter. The kinetics of InAs NW dissolution in radiolytic water is investigated by analyzing the source supply, surface reaction and product diffusion steps in the dissolution process. We find surface reaction limited dissolution fits well with our experimental results and the activation energy should be constant during the whole dissolution process even when the diameter of InAs NWs is as small as 5 nm. The present results are significant for a quantitative understanding of liquid phase reactions for 1D systems and for design and optimization of dissolution processes.