Atomically dispersed nickel-nitrogen-sulfur species anchored on porous carbon nanosheets for efficient water oxidation.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 30918251.
- Also identified by DOI 10.1038/s41467-019-09394-5 and PMC identifier 6437202.
- 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
Developing low-cost electrocatalysts to replace precious Ir-based materials is key for oxygen evolution reaction (OER). Here, we report atomically dispersed nickel coordinated with nitrogen and sulfur species in porous carbon nanosheets as an electrocatalyst exhibiting excellent activity and durability for OER with a low overpotential of 1.51 V at 10 mA cm<sup>-2</sup> and a small Tafel slope of 45 mV dec<sup>-1</sup> in alkaline media. Such electrocatalyst represents the best among all reported transition metal- and/or heteroatom-doped carbon electrocatalysts and is even superior to benchmark Ir/C. Theoretical and experimental results demonstrate that the well-dispersed molecular S|NiN<sub>x</sub> species act as active sites for catalyzing OER. The atomic structure of S|NiN<sub>x</sub> centers in the carbon matrix is clearly disclosed by aberration-corrected scanning transmission electron microscopy and synchrotron radiation X-ray absorption spectroscopy together with computational simulations. An integrated photoanode of nanocarbon on a Fe<sub>2</sub>O<sub>3</sub> nanosheet array enables highly active solar-driven oxygen production.