Abstract
An experiment was conducted to demonstrate that the MoSe 2 /Mo core-shell hierarchical nanostructures by a low-temperature plasma-assisted selenization process on the Mo 3D-hierarchical nanostructures with controlled shapes deposited by a glancing angle deposition system (GLAD) system. The mixed phases of MoSe 2 /Mo core?shell hierarchical nanostructures can be achieved at the low selenization temperature of 400°C, whereas the 2H-MoSe 2 /Mo core-shell 3D-hierarchical nanostructures dominate once the plasma-assisted selenization temperature exceeds 500°C. In particular, the mixed MoSe 2 /Mo core-shell nanoscrews exhibit the highest catalytic activities, with a Tafel slope as low as 34.7 mV dec -1 , which is close to the theoretical value of 29 mV dec -1 and a low potential of -166 mV at J = 10 mA cm -2 dominated by a Volmer-Tafel reaction for the ideal hydrogen evolution reaction (HER) process. The high catalytic activities are attributed to the increased density of exposed edges and the metallic phase of the MoSe 2 shell, providing a fast charge transfer.