Ultrafine Defective RuO₂ Electrocatayst Integrated on Carbon Cloth for Robust Water Oxidation in Acidic Media

Abstract

Developing efficient and durable electrocatalysts for the oxygen evolution reaction (OER) in acidic media is attractive but still challenging. In this study, ultrafine defective RuO2 nanoparticles are successfully prepared on carbon cloth by means of dip‐coating, annealing, and acid etching. As a self‐supported electrocatalyst, it exhibits an ultralow overpotential of 179 mV in 0.5 m H2SO4. More importantly, the high activity can be well maintained for 20 h. The density functional calculations revealed that the defect can not only increase the number of active sites but also improve the intrinsic OER activity.

Recent Development of Oxygen Evolution Electrocatalysts in Acidic Environment

“…Carbon-based supporting materials have been widely used due to their high electrical conductivity and large surface area (e.g., Vulcan XC-72: Brunauer-Emmett-Teller (BET) surface area ≈235 m 2 g −1 ; conductivity ≈21 S cm −1 ). The drawbacks of carbon black, such as the easy oxidation of carbon to CO 2 , have triggered the development of antioxidized supporting materials, such as 3D graphite foam, [141] C 3 N 4 /nitrogen-doped graphene, [142] carbon cloth, [143] and graphitic carbon nitride. [112] Besides carbon-based materials, other alternatives, such as SiO 2 , [144] TiO 2 , [43] Nb-doped TiO 2 (NTO), [139] and antimony-or fluorinedoped tin oxide (ATO [110,145,146] or FTO [140] ) with strong corrosion resistance, have also been extensively studied in OER in acidic media.…”

Dopants fixation of Ruthenium for boosting acidic oxygen evolution stability and activity

“…It has been proven that the over-oxidation of Ru-based materials results in soluble Ru x >4 (e.g. RuO 4 ) derivatives 14 , 26 , 27 , which seriously hinders the application of RuO 2 in the commercial PEM devices.…”

Rare-earth-regulated Ru-O interaction within the pyrochlore ruthenate for electrocatalytic oxygen evolution in acidic media

“…We found that the average valence state decreased as the RE ionic radius increased, and Nd 2 Ru 2 O 7 showed the lowest valence state of 3.68 in particular, which matched well with the relationship between activity and radius. Lower oxidation state of Ru possessed preferable OER kinetics, which could be attributed to more exposed unsaturated Ru active sites, thus possessing higher intrinsic activity [43,44]. Furthermore, improved stability was observed due to inhibited dissolution of Ru active sites as the valence state of Ru was below +4.…”