Atomically dispersed hybrid Ni/Ir sites for photoelectrocatalysis
by Chunhua Cui, Marc Heggen, Wolf-Dietrich Zabka, Wei Cui, Jürg Osterwalder, Benjamin Probst and Roger Alberto
Atomically dispersed supported catalysts can maximize atom efficiency and minimize cost. In spite of much progress in gas-phase catalysis, applying such catalysts in the field of renewable energy coupled with electrochemistry remains a challenge due to their limited durability in electrolyte. Here, we report a robust and atomically dispersed hybrid catalyst formed in situ on a hematite semiconductor support during photoelectrochemical oxygen evolution by electrostatic adsorption of soluble monomeric [Ir(OH)6]2− coupled to positively charged NiOx sites. The alkali-stable [Ir(OH)6]2− features synergistically enhanced activity toward water oxidation through NiOx that acts as a “movable bridge” of charge transfer from the hematite surface to the single iridium center. This hybrid catalyst sustains high performance and stability in alkaline electrolyte for >80 h of operation. Our findings provide a promising path for soluble catalysts that are weakly and reversibly bound to semiconductor-supported hole-accumulation inorganic materials under catalytic reaction conditions as hybrid active sites for photoelectrocatalysis.
Chunhua Cui, Marc Heggen, Wolf-Dietrich Zabka, Wei Cui, Jürg Osterwalder, Benjamin Probst and Roger Alberto: Atomically dispersed hybrid Ni/Ir sites for photoelectrocatalysis, Nature Communications 8 (2017) 1341.