In an open-acess paper published in Nature Communications, Griffith University (Australia) researchers report having enhanced the catalytic activity of CoSe₂ for oxygen evolution in water splitting by incorporating both Fe dopants and Co vacancies into atomically thin CoSe₂ nanobelts.

CoSe₂ nanobelts are ultrathin sheets made out of a lattice of cobalt (Co) and selenium (Se).

Both the iron doping and creating cobalt vacancies, when applied individually, improve the nanobelt’s ability to speed up reactions to a small degree. The Griffith advance was discovering that when both processes are put together their combined effect substantially increases the power of nanobelts to speed up reactions.

Fe doping and Co vacancy synergistically tune the electronic states of Co₂ to a near-optimal value, resulting in greatly decreased binding energy of OH* (ΔE_OH) without changing ΔE_O, and consequently lowering the catalytic overpotential. The proper combination of multiple defect structures is promising to unlock the catalytic power of different catalysts for various electrochemical reactions.

—Dou et al.

Our discovery, that by combining these two processes we can push this catalyst to its activity limit, is very exciting. This unlocks not just the catalytic power of CoSe₂ nanobelts, but catalysts for all sorts of electrochemical reaction.

—Dr Yuhai Dou, lead author

Australia’s National Hydrogen Strategy (2019) aims to establish Australia’s hydrogen industry as a major global player by 2030.

Resources

• Dou, Y., He, C., Zhang, L. et al. (2020) “Approaching the activity limit of CoSe₂ for oxygen evolution via Fe doping and Co vacancy.” Nat Commun 11, 1664 doi: 10.1038/s41467-020-15498