Tribotronic control and cyclic voltammetry of platinum interfaces with metal oxide nanofluids

Abstract

Nanotribological andelectrochemical behaviorof platinum-nanofluid interfaces are reported for aqueous suspensions ofpositively chargedAl2O3and negatively charged TiO2 nanoparticles, employing Quartz Crystal Microbalance (QCM) and cyclic voltammetry (CV) techniques. Tribotronic methods were employed to adjust the nanoparticles’ positions relative to Pt surface electrodes, and both voltammetry and tribological performance measures were observed to be highly sensitive to the adjustments. Interfacial friction levels were observed to be higher for both types of nanoparticles when electrostatically driven towards the surface.For electric fields of sufficient amplitude and duration, the TiO2nanosuspension exhibited properties consistent with reversible electrophoretic deposition of the nanoparticles, accompanied by changes in the electrochemical attributes of the electrode itself. Overall, the study suggests a method for active tribological control and optimization of device performance in applications where suspensions of charged nanoparticles are present and can be exposed to external fields.