Flattening bent Janus nanodiscs expands lattice parameters

Abstract

Nanoscale lattice parameter engineering is a potentially powerful tool for tailoring the electronic properties of nanomaterials. The nascent strain in juxtaposed hetero-interfaces of nanocrystals was recently shown to substantially affect the energy states of the exposed surfaces and improve catalytic activity; however, practical implementations of this design strategy are rare. Herein, we report that Rh3S4 and Cu31S16 can be combined to produce a bent Janus -type nanodisc in which the surface strain can be controlled precisely by modulating the curvature. These nanodiscs are conveniently pre-pared by replacing copper with rhodium in Cu31S16 via anisotropic cation exchange, which induces lattice strain and bends the nano -discs. Flattening the Rh3S4/Cu31S16 nanodisc leads to a unique surface lattice structure and affords superior electrocatalytic perfor-mance in the hydrogen evolution reaction. We demonstrate a gen-eral and straightforward strategy for controlling the lattice strains in hetero-nanostructures and for systematically improving their catalytic performance.