Sodium Hexa-Titanate Nanowires Modified with Cobalt Hydroxide Quantum Dots as an Efficient and Cost-Effective Electrocatalyst for Hydrogen Evolution in Alkaline Media.

A novel electrocatalyst with high activity and enhanced durability toward the hydrogen evolution reaction (HER) in alkaline media has been designed and fabricated based on sodium hexa-titanate (Na 2 Ti 6 O 13 ) nanowires synthesized by a hydrothermal process and modified with Co(OH) 2 quantum dots (QDs) by a facile chemical bath deposition (CBD) method. The current response of the developed Ti/Na 2 Ti 6 O 13 /Co(OH) 2 nanocomposite electrode attained 10 mA cm -2 at an overpotential of 159 mV. The nanocomposite electrode exhibited a high stability at an applied current of 100 mA cm -2 . The remarkable catalytic behavior was achieved with a loading amount of ca. 0.06 mg cm -2 cobalt hydroxide. This is attributed to the high electrochemically active surface area (EASA) gained by the nanowire-structured substrate and considerable enhancement of electrochemical conductivity with the use of Co(OH) 2 quantum dots as an active material. The superior catalytic activity and high stability show that the developed catalyst is a promising candidate for hydrogen production in alkaline media.