Nanocomposite systems based on iron(III) oxide (Fe2O3) and graphitic carbon nitride (gCN) possess a great potential as photo(electro)catalysts for environmental remediation and energy generation. In this field, a key issue is the fabrication of supported materials directly grown onto suitable substrates and possessing tailored features. In the present study, Fe2O3–gCN nanomaterials are prepared by an innovative two-step strategy, consisting of initial plasma assisted-chemical vapor deposition of iron(III) oxide on conducting glass substrates and subsequent functionalization with low amounts of gCN by a facile electrophoretic deposition process. Attention is dedicated to the use of two different forms of carbon nitride, obtained from melamine or melamine + cyanuric acid, in order to finely tune the resulting material composition. In this work, x-ray photoelectron spectroscopy was used to characterize the pristine Fe2O3 deposit as well as two Fe2O3–gCN composite materials prepared starting from different gCN powders. A detailed analysis of the obtained spectroscopic data reveals the occurrence of a direct electronic interplay between single constituents, dependent on material characteristics. The related results may act as useful guidelines for the design of photo(electro)catalysts endowed with specific properties, of importance for sustainable applications.