Perovskite‐Type Oxynitride Nanofibers Performing Photocatalytic Oxygen and Hydrogen Generation

Ba5Nb4O15 nanofibers with tailored nanofiber diameters are prepared via electrospinning, and treated in ammonia gas to synthesize niobate oxynitride nanofibers. Most importantly, the retain their fiber morphology during ammonolysis, diameter of converted fibers can be adjusted. Only a thorough characterization, including detailed Rietveld refinements, reveal that ammonolysis results not only BaNbO2N, but also generates Ba2NbO3N as additional phase. Such BaNbO2N–Ba2NbO3N composite adjusted applied photocatalytic water oxidation hydrogen generation. After decoration CoNbO4 or Pt cocatalyst, materials show diameter-dependent activity, respectively, an optimum diameter. The presented synthesis demonstrates novel sol–gel-derived possibility for nanostructuring oxynitrides, which pave way new strategies nanostructured complex oxynitrides.