Ion Exchange Synthesis of Cobalt Ion Modified Titanate Nanoarray as an Electrocatalyst toward Efficient Hydrogen Evolution Reaction

Abstract

Cobalt ion modified titanate nanoarray (CTO NA) with a three-dimensional hierarchical structure is synthesized via a facile ion exchange strategy and further developed as an electrocatalyst toward efficient hydrogen evolution reaction (HER). In 0.1 M KOH solution, CTO NA exhibits a low Tafel slope of 93 mV dec-1 and a small overpotential of 199 mV at a current density of 10 mA cm-2 as well as high electrochemical stability for HER. The superior electrocatalytic performance of CTO NA is attributed to the unique chemical composition and layered crystal structure for improved electrode kinetics. Meanwhile, the three-dimensional hierarchical morphology of CTO NA also contributes to fast charge transfer and greatly enhanced mass transport in electrochemical reaction. This work holds a great promise for the as-prepared CTO NA to be an alternative for the noble metals based catalysts toward large scale hydrogen production via water electrolysis.