Activating Titanium Metal with H2 Plasma for the Hydrogen Evolution Reaction.

Abstract

Developing a high-performance nonprecious metal electrocatalyst for water splitting is a strong demand for the large-scale application of electrochemical H2 production. In this work, we design a facile and scalable strategy to activate titanium metal for the hydrogen evolution reaction (HER) in alkaline media through incorporating hydrogen into the α-Ti crystal lattice by H2 plasma bombardment. Benefiting from the accelerated charge transfer and enlarged electrochemical surface area after H2 plasma treatment, the H-incorporated Ti shows remarkably enhanced HER activity with a much lower overpotential at -10 mA cm-2 by 276 mV when compared to the pristine Ti. It is revealed that the retention of the incorporated H(D) atoms in the Ti crystal lattice during HER accounts for the durable feature of the catalyst. Density functional theory calculations demonstrate the effectiveness of hydrogen incorporation in tuning the adsorption energy of reaction species via charge redistribution. Our work offers a novel route to activate titanium or other metals by H incorporation through a controllable H2 plasma treatment to tune the electronic structure for water splitting reactions.