Improving the Oxygen Evolution Activity and Stability of Nb-Doped TiO₂-Supported RuO₂ by a SnO₂ Interlayer: A Model Catalyst Study on Single-Crystal Oxide Heterostructures

Abstract

The introduction of a SnO2(110) interlayer remarkably enhances the oxygen evolution reaction (OER) activity and electrochemical stability of RuO2/Nb-doped TiO2(110) single-crystal oxide heterostructure. The SnO2 interlayer reduces the OER overpotential of RuO2/Nb:TiO2(110) by 25 and 55 mV before and after a chronopotentiometry (CP) measurement of 0.5 mA cm–2 for 2 h, respectively. The addition of the SnO2 interlayer significantly reduces the interfacial resistance between RuO2 and TiO2 in the as-pristine state and the resistance remained nearly unchanged even after the CP. Additionally, the SnO2 interlayer stabilizes the interface between surface RuO2(110) and substrate TiO2(110) under OER, suppressing structural degradation such as nanovoid generation at the RuO2/TiO2 interface. Hence, the SnO2 interlayer is correlated with the enhanced OER activity and stability of the RuO2/Nb:TiO2(110) model catalysts because it mitigates both electrical and structural mismatches of the surface RuO2 layer and the TiO2 substrate.

Advanced Electrocatalyst Supports for Proton Exchange Membrane Water Electrolyzers

“…The SnO 2 interlayer stabilizes the interface between the RuO 2 (110) surface and the TiO 2 (110) substrate during OER, thus preventing structural degradation, including the formation of nanovoids at the RuO 2 /TiO 2 interface. Therefore, the presence of the SnO 2 interlayer is associated with the improved stability of the RuO 2 /Nb: TiO 2 (110) model catalysts as it mitigates both the electrical and structural discrepancies between the surface RuO 2 layer and the TiO 2 substrate . In another study, IrO 2 NPs, each with a consistent size of around 2 nm, are uniformly dispersed across Nb and Ta-doped SnO 2 supports, forming a fused-aggregate structure that exhibits exceptionally high performance, mainly owing to its significantly high surface area.…”

RuO2 Catalysts for Electrocatalytic Oxygen Evolution in Acidic Media: Mechanism, Activity Promotion Strategy and Research Progress

“…The TiO 2 carrier with abundant oxygen vacancies significantly improves the OER activity and stability of the loaded RuO 2 -OER nanoparticles. Naoto Todoroki et al introduced SnO 2 to form a RuO 2 /Nb-TiO 2 single-crystal oxide heterojunction catalyst ( Figure 5 B–D) [ 73 ]. The SnO 2 interlayer stabilized the interface between RuO 2 and TiO 2 layers and thus reduced electrode resistance and lattice strains, inhibiting the formation of RuO 2 /TiO 2 interface nanodomains and structural damage and alleviating the electrocatalytic and structural mismatch.…”

“…The TiO2 carrier with abundant oxygen vacancies significantly improves the OER activity and stability of the loaded RuO2-OER nanoparticles. Naoto Todoroki et al introduced SnO2 to form a RuO2/Nb-TiO2 single-crystal oxide heterojunction catalyst (Figure 5B-D) [73]. The SnO2 interlayer stabilized the interface be- The 2D hexagonal nanosheet shape fully exposes active sites (Figure 5E-H) and improves the utilization efficiency of precious metal atoms.…”

Efficient Ozone Evolution Anode of Tantalum Nitride with Cubic Crystal Structure

“…In this study, we postulated a stacking structure of a surface Ta oxide layer on a Ta nitride thin film for effective O 3 evolution anodes and consequently synthesized Ta nitride thin films with various crystal structures on a Pt substrate using the reactive arc plasma deposition (APD) method under N 2 partial pressure. − The resulting crystal structures of the Ta nitrides have cubic, hexagonal, and mixed crystal structures depending on the APD conditions, particularly the deposition rates and thicknesses of the TaN thin films. The estimated O 3 evolution efficiency of the TaN thin film anode with a cubic crystal structure is highest in the potential region of 3.2–5.2 V, outperforming those of PbO 2 - and SnO 2 -based electrodes.…”