Well-Dispersed Ruthenium in Mesoporous Crystal TiO 2 as an Advanced Electrocatalyst for Hydrogen Evolution Reaction

TiO mesoporous crystal has been prepared by one-step corroding process via an oriented attachment (OA) mechanism with SrTiO as precursor. High resolution transmission electron microscopy (HRTEM) and nitrogen adsorption-desorption isotherms confirm its mesoporous crystal structure. Well-dispersed ruthenium (Ru) in the mesoporous nanocrystal TiO can be attained by the same process using Ru-doped precursor SrTi Ru O . Ru is doped into lattice of TiO , which is identified by HRTEM and super energy dispersive spectrometer (super-EDS) elemental mapping. X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance spectroscopy (EPR) suggest the pentavalent Ru but not tetravalent, while partial Ti in TiO accept an electron from Ru and become Ti , which is observed for the first time. This Ru-doped TiO performs high activity for electrocatalytic hydrogen evolution reaction (HER) in alkaline solution. First-principles calculations simulate the HER process and prove TiO :Ru with Ru and Ti holds high HER activity with appropriate hydrogen-adsorption Gibbs free energies (Δ G ).