Open AccessElectrocatalytic Reaction Induced Colloidal Accumulation: The Role of Dielectrophoresis
Author(s) -
Abimbola Ayodeji Ashaju,
Jeffery A. Wood,
Rob G.H. Lammertink
Publication year - 2022
Publication title -
langmuir
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.042
H-Index - 333
eISSN - 1520-5827
pISSN - 0743-7463
DOI - 10.1021/acs.langmuir.1c01938
Subject(s) - dielectrophoresis , electric field , chemical physics , particle (ecology) , bimetallic strip , electrokinetic phenomena , chemistry , catalysis , hydrogen peroxide , surface charge , nanotechnology , micrometer , electrode , colloid , chemical engineering , electrocatalyst , materials science , microfluidics , electrochemistry , organic chemistry , physics , oceanography , engineering , quantum mechanics , geology , optics
A surface-driven flow is generated during the electrocatalytic reaction of a platinum-gold bielectrode within hydrogen peroxide. This flow can be experimentally visualized and quantified using micrometer-sized particles that are transported by a flow field. Tracer particles, which possess an inherent surface charge, also interact with the induced electric field and exhibit a collective behavior at the surface of the electrodes where they accumulate. The underlying mechanism for the accumulation dynamics demonstrated by these catalytic pump systems has so far been lacking. In this work, the accumulation dynamics and kinetics were experimentally investigated. With use of numerical simulations, we demonstrate that the self-driven particle accumulation is controlled by a positive dielectrophoretic force, mediated by the reaction-induced electric and flow field. These results contribute to the fundamental knowledge on immobilized bimetallic systems.