Assessing and Mitigating Surface Contamination of Carbon Electrode Materials

Despite a few studies reporting otherwise, graphitic carbon surfaces were generally thought to be hydrophobic prior to the 2010s. However, many reports in the past 6 years showed that they are much more hydrophilic than previously thought. It was revealed that hydrocarbons adsorbed from ambient air masked the intrinsic surface wettability. Later work showed that other surface properties such as double layer capacitance and heterogeneous electron transfer rate were also impacted by the same contamination phenomenon. Since surface contamination is difficult to avoid completely, it is increasingly important to take this effect into consideration in both experimental design and data analysis. Will the experiment be negatively impacted by the unintentional contamination from the environment? How is one to properly characterize the surface to detect potential contamination? How can the contamination be removed if it has already occurred? In this protocol paper, we try to answer these questions by reviewing the background of airborne contamination of graphitic carbon materials and outlining procedures to properly handle them in the research lab to minimize its negative impact on experiments.