Comprehensive spectroscopic and electrochemical investigation of multi-interface colloidal graphite electrodes

Glass–graphite and glass–gold–graphite electrodes were fabricated and examined to elucidate their structural, chemical, and electronic properties that are important for different applications in energy storage, and for the fabrication of robust electron sources in Micro-Electro-Mechanical Systems and vacuum nanoelectronics. Surface-sensitive techniques including X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, reflection electron energy loss spectroscopy, and spatially resolved XPS mapping were employed to determine elemental composition, bonding states, work function, and electronic excitation behavior. The interfaces and layer structures were examined by scanning electron microscopy coupled with Energy Dispersive X-ray Spectroscopy. In addition, Raman spectroscopy was used to obtain complementary insight into the degree of graphitic ordering and the nature and distribution of defects. Moreover, electrochemical impedance spectroscopy was carried out to assess and characterize the prepared electrodes in electrochemical cells along with cyclic voltammetry technique and the results were validated by the elimination voltammetry of linear scan technique. Finally, the obtained results revealed a high capacitive behavior governed by the formed interfaces and the high porosity of the graphite films, with values ranging from several hundred microfarads to millifarads.