Bulk layered heterojunction as an efficient electrocatalyst for hydrogen evolution.

We describe the spontaneous formation of composite chalcogenide materials that consist of two-dimensional (2D) materials dispersed in bulk and their unusual charge transport properties for application in hydrogen evolution reactions (HERs). When MoS as a representative 2D material is deposited on transition metals (such as Cu) in a controlled manner, the sulfidation reactions also occur with the metal. This process results in remarkably unique structures, that is, bulk layered heterojunctions (BLHJs) of Cu-Mo-S that contain MoS flakes inside, which are uniformly dispersed in the CuS matrix.

Wafer-scale single-domain-like graphene by defect-selective atomic layer deposition of hexagonal ZnO.

Large-area graphene films produced by means of chemical vapor deposition (CVD) are polycrystalline and thus contain numerous grain boundaries that can greatly degrade their performance and produce inhomogeneous properties. A better grain boundary engineering in CVD graphene is essential to realize the full potential of graphene in large-scale applications. Here, we report a defect-selective atomic layer deposition (ALD) for stitching grain boundaries of CVD graphene with ZnO so as to increase the connectivity between grains.