GaN (E(g) = similar to 3.4 eV) was photoelectrochemically characterized and the energetic position of its bandedges determined with respect to SHE. Electrochemical impedance spectroscopy was employed to analyze the interface, determine the space charge layer capacitance, and, subsequently obtain the flatband potential of GaN in different aqueous electrolytes. The flatband potential of GaN varied at an approximately Nernstian rate in aqueous buffer electrolytes of different pHs indicating acid-base equilibria at the interface.