Atomically dispersed hybrid nickel-iridium sites for photoelectrocatalysis.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 29116238.
- Also identified by DOI 10.1038/s41467-017-01545-w and PMC identifier 5677126.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
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)<sub>6</sub>]<sup>2-</sup> coupled to positively charged NiO<sub>x</sub> sites. The alkali-stable [Ir(OH)<sub>6</sub>]<sup>2-</sup> features synergistically enhanced activity toward water oxidation through NiO<sub>x</sub> 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.