A scalable infrared-heating CVD method was developed to grow few-walled WSe 2 or WS 2 nanotube arrays in situ filled with highly conductive single-crystal W 18O 49, and a simple pressure control led to their universally uncapped top-ends. Open-ended WS 2 nanotubes grown on the W substrate performed excellently as an electrocatalyst to facilitate the HER in acid, contributing to high-density active edge sites and good electronic coupling between the substrate and nanotubes.
Aligned W 18O 49-filled few-walled WSe 2 or WS 2 nanotubes were directly grown on W substrates via a scalable infrared-heating CVD method. Uncapping greatly improved the catalytic efficiency of WS 2 nanotubes for the HER in acid, due to the high-density exposed 2H-WS 2 edge sites of open-ended nanotubes.