Rational entry-diffusion induced Kirkendall effect towards Au2S nanotubes

Semiconductor nanotubes manifesting large surface area , high tensile strength , light weight, fast electron transfer kinetics and high biocompatibility have attracted tremendous attention and find widespread applications. Rational design and preparation of semiconductor nanotubes with such a unique morphology to maximum their performance and therefore, to fulfill their applications is still a challenge. Herein, we report a strategy that is capable of rationalizing entry-diffusion of Au  +  ions into Cu 2-x S nanorods based on the Kirkendall effect , accomplishing consecutive morphology control from solid nanorods to nanotubes , and ultimately to nanorings of Au 2 S. The structure and composition of Au 2 S nanotubes were further confirmed through X-ray photoelectron spectroscopy, annular bright-field scanning transmission electron microscopy-energy dispersive spectroscopy and scanning transmission electron microscopy and Aberration-corrected transmission electron microscopy . Compared with nanorods , Au 2 S nanotubes demonstrated significantly enhanced catalytic activity in electrocatalytic hydrogen evolution reaction , a remarkably low overpotential of 602.0 mV at a current density of −10 mA cm −2 and a relatively low Tafel slope of 36.87 mV dec −1 in 0.5 M H 2 SO 4 solution. It is anticipated that this novel strategy of mediating ion diffusion rate would inspire rational control of unique morphologies and structures of semiconductor nanocrystals , providing a platform for further applications based on nanomaterials .