Turing-Type Patterns on Electrode Surfaces
Yong-Jun Li,
Julia Oslonovitch,
Nadia Mazouz,
Florian Plenge,
Katharina Krischer,*
Gerhard Ertl
We report stationary, nonequilibrium potential and adsorbate
patterns with an intrinsic wavelength that were observed in an electrochemical system with a specific type of
current/electrode-potential (I-
DL)
characteristic. The patterns emerge owing to the interplay of a
self-enhancing step in the reaction dynamics and a long-range inhibition by migration currents rather than by diffusion. Theoretical analysis revealed that this self-structuring of the electrode occurs in
all electrochemical systems with an S-shaped
I-
DL characteristic in wide and
well-accessible parameter ranges. This unusual pattern-forming instability in electrochemical systems has all the characteristics of
the mechanism proposed by Turing in 1952 in the framework of an early
theory of morphogenesis. Our finding might account for structure
formation in certain biological systems that have gradients in the
electric potential and may open new paths for fabricating patterned
electrodes.
Fritz-Haber-Institut der Max-Planck-Gesellschaft,
Faradayweg 4-6, D-14195 Berlin, Germany.
*
To whom correspondence should be addressed. E-mail:
krischer{at}fhi-berlin.mpg.de