Nitrogen-doped carbon nanotubes encapsulating PtRu alloy nanoparticles as pH-universal hydrogen evolution reaction electrocatalysts

Nitrogen-doped carbon nanotubes (NCNTs) that encapsulate PtRu alloy nanoparticles were fabricated by performing chemical vapor deposition using anodic aluminum oxide templates and subsequent annealing in ammonia. Pt and Ru had low contents of 0.8 wt% and 4.2 wt%, respectively, but their combined contributions with nitrogen doping resulted in excellent electrocatalytic activity of the PtRu@NCNT composites for the hydrogen evolution reaction in alkaline, acid and neutral electrolytes.