Electrode Surface Morphology Characterization by Atomic Force Microscopy

Abstract

The introduction of hydrogen into a metal during electrolysis of water involves primarily the metallic surface. The effect of surface morphology on electrochemical reaction kinetics is well described in the literature 1 therefore it seems to be reasonable to assume that the surface morphology of the cathodes could play a role in the electrochemical metal-hydride formation. Actually, a wide variety of surface features and profiles have been observed in the Pd cathodes typically employed in excess heat production experiments. These features are noted in both the as-prepared samples and the electrolyzed ones. In order to establish a correlation between the occurrence of a particular surface morphology and calorimetric results, it is necessary to identify a useful metric with which to describe and compare the different surface morphologies. In this work an approach based on Atomic Force Microscopy (AFM) has been investigated. The method is oriented toward the identification of parameters suitable for a prescreening of the materials. Introduction In recent years we have begun a research project focused on the study of the material science aspects of cold fusion. In particular, the preliminary results have pointed out a strong correlation existing between the metallurgical and surface properties of the Pd cathodes used in electrochemical experiments, and the occurrence of excess heat production [2]. We investigated cathode features including both bulk features (crystallography, deuterium loading, electrochemical behavior, hardness) and surface characteristics. In this paper, we concentrate on the study of the surface morphology of the Pd electrodes, leaving the other aspects of material science to other papers [3],[4]. In particular, we limit our analysis to the length scale of a few micrometers, which characterizes the surface morphology “inside” each crystal grain. Grain boundary features fall outside this range, and they have been considered elsewhere [3],[4]. The experimental analysis has been carried out by Atomic Force Microscopy (AFM). This technique [5] is able to collect tri-dimensional surface morphology maps, with spatial resolution up to a fraction of a nanometer. The digitized images have been elaborated to extract numerical parameters and parametric functions, which could make the comparison between the various samples easier and more objective. The numerical procedure, based on the computation of Fourier transforms, aims to define a surface status function that can describe and compare the

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Cite this paper

@inproceedings{Sarto2010ElectrodeSM, title={Electrode Surface Morphology Characterization by Atomic Force Microscopy}, author={Francesca Sarto and Emanuele Castagna and Maddalena Sansovini and Sandro Lecci and Vittorio Violante and David Knies and Graham Hubler}, year={2010} }