Bi-doped Ruthenium Oxide Nanocrystal for Water Oxidation in Acidic Media
Abstract
There is an urgent need to develop a cost-effective and highly efficient acidic OER catalyst to support the progress of proton exchange membrane water electrolysis technology. Ruthenium-based catalysts, which possess high activity and significantly lower cost compared to iridium, emerge as competitive candidates. However, the suboptimal stability constrains the widely application of RuO2. Herein, we develop ultra-small Bi0.05Ru0.95O2 nanocrystals with diameters of approximately 6.5 ± 0.1 nm for acidic OER. The Bi0.05Ru0.95O2 nanocrystal electrocatalyst exhibits a low overpotential of 203.5 mV at 10 mA cm-2 and 300+ hours stability under a high water-splitting current density of 100 mA cm−2 in 0.5 M H2SO4 with a low decay rate of 0.44 mV h-1. Density functional theory (DFT) calculation results confirmed the adsorbate evolving mechanism (AEM) occurring on Bi0.05Ru0.95O2, which prevents lattice oxygen from participating in reaction, thus avoids the collapse of structure. We proved that the Bi dopants could play a crucial role in not only reducing the energy barrier of the potential-determining step, but also delivering electrons to Ru sites, thereby alleviating the over-oxidation of Ru active sites and enhancing operation durability.
- This article is part of the themed collection: 2024 Nanoscale HOT Article Collection