Roughened Zn‐Doped Ru–Ti Oxide Water Oxidation Electrocatalysts by Blending Active and Activated Passive Components

An approach to decreasing the overpotential, increasing the stability, and optimizing the noble-metal composition of electrocatalysts for the oxygen evolution reaction (OER) in acidic media is demonstrated. Essential components of this approach are: 1) combining an active (unstable Ru) component with a dopant (Zn)-activated passive (stable Ti) element, 2) blending these elements by co-electrodeposition in an acidic environment in which dissolution of the unstable component (excess Ru) promotes roughness, and 3) further increasing the roughness of the resultant electrode through chemical inhomogeneity by the incorporation of Ti and through structural inhomogeneity by incorporation of Zn in RuO2. The composition of the electrode with the maximal activity is Ru0.258Ti0.736Zn0.006Ox, and its activity is four times higher than that of RuO2. The electrochemical stability towards the OER follows the order RuTiZn>RuTi>RuZn>Ru. This design strategy provides a facile method to improve activity without compromising stability.