A nitridation route to construct high-activity interfaces toward alkaline hydrogen evolution

Abstract

The high cost and sluggish H₂O dissociation kinetics of Pt-based electrocatalysts urge the development of cost-effective and high-activity catalysts for the hydrogen evolution reaction (HER) via electronic structure engineering derived via interfacial doping. Herein, we report a nitridation route to prepare a hierarchical structured Ru/TiO_xN_y nanobelt electrocatalyst through the thermal treatment of Ru/H₂Ti₂O₅ in ammonia. As-synthesized Ru/TiO_xN_y shows high HER activity with a low overpotential of 16 mV at 10 mA cm⁻², a small Tafel slope of 42 mV dec⁻¹, and a high mass activity of 4.2 A mg⁻¹ at 100 mV in alkaline solution, superior to most previously reported noble-metal electrocatalysts. The characterization results imply that nitridation could modify the chemical environment and electronic structure at the interfaces of Ru/TiO_xN_y, which would not only decrease the adsorption energy of hydrogen intermediates via reducing the content of oxygen vacancies, but would also improve electron transfer through Ru–N bonds. This work provides a meaningful strategy for the design and synthesis of cost-effective and high-activity electrocatalysts for electrochemical energy conversion.