Electrooxidation of substoichiometric titanium nitrides, TiN1 − x, 0 < x < 0.5

► Substoichiometric titanium nitrides, TiN1 − x, were fabricated by a ceramic process. ► The different compositions and the purity of the materials were very well controlled. ► Electrochemical oxidation allows the obtention of TiN1 − xOx free of TiO2. ► The N/O ratio can be easily tuned. ► The method is extendable to other metal oxynitrides