Activation of Osmium by the Surface Effects of Hydrogenated TiO Nanotube Arrays for Enhanced Hydrogen Evolution Reaction Performance.

Efficient cathodes for the hydrogen evolution reaction (HER) in acidic water electrolysis rely on the use of expensive platinum group metals (PGMs). However, to achieve economically viable operation, both the content of PGMs must be reduced and their intrinsically strong H adsorption mitigated. Herein, we show that the surface effects of hydrogenated TiO nanotube (TNT) arrays can make osmium, a so far less-explored PGM, a highly active HER electrocatalyst.