Abstract
Efficient oxygen-evolution reaction catalysts are required for the cost-effective generation of solar fuels. Metal selenides have been reported as promising oxygen-evolution catalysts; however, their active forms are yet to be elucidated. Here we show that a representative selenide catalyst, nickel selenide, is entirely converted into nickel hydroxide under oxygen-evolution conditions. This result indicates that metal selenides are unstable during oxygen evolution, and the in situ generated metal oxides are responsible for their activity. This knowledge inspired us to synthesize nanostructured nickel iron diselenide, a hitherto unknown metal selenide, and to use it as a templating precursor to a highly active nickel iron oxide catalyst. This selenide-derived oxide catalyses oxygen evolution with an overpotential of only 195 mV for 10 mA cm−2. Our work underscores the importance of identifying the active species of oxygen-evolution catalysts, and demonstrates how such knowledge can be applied to develop better catalysts.
Highlights
Efficient oxygen-evolution reaction catalysts are required for the cost-effective generation of solar fuels
The different lattice fringes in high-resolution Transmission electron microscopy (TEM) (HRTEM) images of samples before and after oxygen-evolution reaction (OER) confirmed the total conversion of NiSe into Ni(OH)[2]
Using NiSe as a representative example of metal selenides, we show that metal selenides are converted into metal oxides or hydroxides under OER conditions
Summary
Efficient oxygen-evolution reaction catalysts are required for the cost-effective generation of solar fuels. This result indicates that metal selenides are unstable during oxygen evolution, and the in situ generated metal oxides are responsible for their activity This knowledge inspired us to synthesize nanostructured nickel iron diselenide, a hitherto unknown metal selenide, and to use it as a templating precursor to a highly active nickel iron oxide catalyst. This knowledge promoted us to purposely use metal selenides as templating precursors to highly active metal oxide OER catalysts, because methods to produce ultrasmall nanostructured metal selenides are readily available[12,13,14,15] Following this strategy, we synthesize a hitherto unknown selenide, nickel iron diselenide (NixFe1 À xSe2), which upon in situ transformation into oxides, catalyses OER with an overpotential of only 195 mV for a current density of 10 mA cm À 2. The high activity of this NixFe1 À xSe2-derived catalyst is largely due to its desirable nanostructure, inherited from its selenide precursor
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
