Perovskite‐Type Oxynitride Nanofibers Performing Photocatalytic Oxygen and Hydrogen Generation. Issue 15 (15th July 2021) - Hofmann, Anja
Abstract: Ba5 Nb4 O15 nanofibers with tailored nanofiber diameters are prepared via electrospinning, and treated in ammonia gas to synthesize niobate oxynitride nanofibers. Most importantly, the nanofibers retain their fiber morphology during ammonolysis, and the nanofiber diameter of the converted fibers can be adjusted. Only a thorough characterization, including detailed Rietveld refinements, can reveal that the ammonolysis of Ba5 Nb4 O15 results not only in BaNbO2 N, but also generates Ba2 NbO3 N as additional oxynitride phase. Such BaNbO2 N–Ba2 NbO3 N composite nanofibers with adjusted nanofiber diameters are applied in photocatalytic water oxidation and hydrogen generation. After decoration with CoNbO4 or Pt cocatalyst, the materials show a diameter‐dependent photocatalytic activity, respectively, with an optimum nanofiber diameter. The presented synthesis demonstrates a novel sol–gel‐derived possibility for nanostructuring of oxynitrides, which can pave the way for new synthesis strategies of nanostructured complex oxynitrides. Abstract : The synthesis of BaNbO2 N–Ba2 NbO3 N oxynitride nanofibers with adjustable nanofiber diameter via an electrospinning and ammonolysis reaction step is presented. Thorough characterization on the perovskite oxynitride is shown and photocatalytic hydrogen and oxygen evolution activity depending on the nanofiber diameter is demonstrated.