Comment on electrodeposited silicate films: importance of supporting electrolyte.

We have observed similar surface color changes of glassy carbon (GC) after anodic "electrodeposition" with the same electrolytes in the presence or the absence of silanes, indicating that sample color changes can arise from more than one thing and thus should not be used as the sole indicator of silica film formation. Nevertheless, the formation of silicate films during anodic electrodeposition is verified by X-ray photoelectron spectroscopy (XPS) measurements.