Felicidades María! Muy merecido reconocimiento 👏🏻👏🏻👏🏻👏🏻🥳🥳🥳🥳

Thank you María! 🤗

It’s always a challenge to push boundaries and think outside the “conventional” box. Thanks to the hard work and determination of everyone involved that made this work possible! 👏 🌿 #STM #OER #NiFeOx #Operando #Nanoscience

This work took years of effort and perseverance, especially since, a few years back, some referees doubted this was even possible.

Big congrats goes to Yunchang for persevering on these super challenging experiments! But STM alone isn’t enough—“seeing is believing,” but understanding chemical composition requires spectroscopic techniques. That’s where XPS and STEM-EDS came in.

Fe incorporates at the edges and cluster on the surface. The resulting dual Ni-Fe active sites were tracked by noise EC-STM on samples prepared in @xilehu-epfl.bsky.social Lab. This is probably the most complex material analyzed so far with nEC-STM.

• Fe incorporation works at multiple levels: increasing the electrochemically active surface area by fragmentation, favouring the formation of NiOOH, and forming dual active sites. Fe further fragments the islands, incorporating at the edges and clustering on the surface.

• Hydroxylation triggers fragmentation: Sofia observed this already under UHV by exposing NiOx islands to water vapor, while Yunchang quantified the fragmentation as soon as the catalyst was immersed in the electrolyte.

What surprised me the most? The “activation” step is actually a fragmentation step that increases surface area—boosting activity in the process, likely a mechanism shared by many 2D transition metal oxides.

We show how 2D NiFeOx (a prototypical material for oxygen evolution from water) works during the reaction. The step by step approach we took in collaboration with our friends from @ecijalab.bsky.social group shed light on the “activation” protocols commonly used in catalysis.