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

Abstract

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 (Na2Ti6O13) 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/Na2Ti6O13/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.