Ordered derivatives on Ti surface enhance the OER activity and stability of Ru-based film electrode

Abstract

The RuO2 catalytic film electrode with long-term durability is becoming increasingly urgent and challenging for catalysis oxygen evolution reaction (OER). Herein, the Ti-oxides (HxTi2+2xOδ/Ti, HTi/Ti) with ordered porous morphology is derived directly from metallic Ti by using a combination method of hydrothermal and ion exchange, and served as a substrate to support RuO2 catalytic film. The porous HTi plays a wedge-like effect, which significantly improve the adhesion of RuO2 catalytic layer and reducing surface cracks. Moreover, the advanced surface characterization techniques evidence a strong catalyst-support interaction between HTi and RuO2, furtherly enhances the binding strength and modifies the orbital structure of Ru-sites. Electrochemical measurements revealed that the prepared RuO2/HTi/Ti possess a low overpotential of 220 mV and 265 mV to afford the current density of 10 mA cm−2 and 50 mA cm−2, respectively, and exhibits a high mass activity of 1760 ± 60 mA gRu−1 at overpotential of 290 mV. Accelerated life test confirmed the robust durability of RuO2/HTi/Ti, which can run stably for up to 11 h at 500 mA cm−2 current density with a low mass loading of 0.1 mg cm−2. The remarkable OER performance is closely associated with the ordered porous HTi and interfacial interactions, which demonstrate the surface engineering to create ordered derivative layers directly from the substrate is important to improve the activity and stability of catalytic film electrode.