Solar fuel generation in the form of hydrogen derived directly from water represents an environmentally friendly technology to obtain clean energy. The perovskite-related oxynitride SrTaO2N is a prospective photoanode candidate with favorable band-edge positions. We have synthesized SrTaO2N nanowires with roughened surfaces by a hydrothermal process on a tantalum substrate and nitridation at 1273 K under flowing ammonia and hydrogen. The nanowires were coated with a ferrihydrite hole storage layer for photoelectrochemical water oxidation under AM 1.5G illumination in 0.1 M NaOH electrolyte (pH 13). The nanowires exhibit an electronic band gap of 2.32 eV, and the photocorrosion can be decreased with ferrihydrite coating. This work is the first trial of a SrTaO2N photoanode based on nanowires and may also be promising for other quaternary oxynitride semiconductors to achieve a one-dimensional morphology.

SrTaO2N nanowire photoanode modified with a ferrihydrite hole-storage layer

256th National Meeting (2018)

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