Ashaju Abimbola A, Wood Jeffery A, Lammertink Rob G H
Soft Matter, Fluidics and Interfaces, MESA+ Institute for Nanotechnology, University of Twente, 7522NB Enschede, The Netherlands.
Langmuir. 2022 Mar 15;38(10):3040-3050. doi: 10.1021/acs.langmuir.1c01938. Epub 2022 Mar 1.
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.
在过氧化氢中铂-金双电极的电催化反应过程中会产生表面驱动流。这种流动可以通过使用由流场传输的微米级颗粒进行实验可视化和量化。具有固有表面电荷的示踪颗粒也会与感应电场相互作用，并在电极表面积累的地方表现出集体行为。迄今为止，这些催化泵系统所展示的积累动力学的潜在机制尚不清楚。在这项工作中，对积累动力学和动力学进行了实验研究。通过数值模拟，我们证明了自驱动颗粒的积累是由反应诱导的电场和流场介导的正介电泳力控制的。这些结果有助于丰富关于固定化双金属系统的基础知识。
