What Determines the Electrochemical Properties of Nitrogenated Amorphous Carbon Thin Films?

Linking structural and compositional features with the observed electrochemical performance is often ambiguous sensitive to known unknown impurities. Here an extensive experimental investigation augmented by computational analyses linked characterization of in situ nitrogen-doped tetrahedral amorphous carbon thin films (ta-C:N). Raman spectroscopy combined X-ray reflectivity shows nitrogen disrupting sp3 C–C structure reference ta-C, supported observations graphitic substitution absorption spectroscopy. The surface roughness also increases, as atomic force microscopy atomic-level analyses. These changes are significant increases hydrogen oxygen content utilizing time-of-flight elastic recoil detection analysis. conductivity a function content, which seen facile reversible outer-sphere redox reaction on ta-C:N electrodes. However, for surface-sensitive inner-sphere (ISR) analytes, it shown that response instead follows content. We argue passivation required adsorption sites decreases rates all chemically different ISR probes investigated nitrogenated surfaces significantly below nitrogen-free sample. This hypothesis can be used readily rationalize many contradictory results reported literature.