Activated carbon nanotubes: a highly-active metal-free electrocatalyst for hydrogen evolution reaction.

In this communication, for the first time, we report on the development and utilization of activated carbon nanotubes (CNTs) as a highly-active metal-free electrocatalyst for the hydrogen evolution reaction (HER) with good durability in acidic electrolytes. This catalyst shows an onset overpotential and an exchange current density of 100 mV and 16.0 × 10(-3) mA cm(-2), respectively. The possible catalytic mechanism for the HER is also proposed.