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Enhanced Photoactivity from Single‐Crystalline SrTaO 2 N Nanoplates Synthesized by Topotactic Nitridation
Author(s) -
Fu Jie,
Skrabalak Sara E.
Publication year - 2017
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201708645
Subject(s) - materials science , crystallization , polyhedron , chemical engineering , nanotechnology , oxygen evolution , chemistry , geometry , mathematics , electrode , engineering , electrochemistry
There are few methods yielding oxynitride crystals with defined shape, yet shape‐controlled crystals often give enhanced photoactivity. Herein, single‐crystalline SrTaO 2 N nanoplates and polyhedra are achieved selectively. Central to these synthetic advances is the crystallization pathways used, in which single‐crystalline SrTaO 2 N nanoplates form by topotactic nitridation of aerosol‐prepared Sr 2 Ta 2 O 7 nanoplates and SrTaO 2 N polyhedra form by flux‐assisted nitridation of the nanoplates. Evaluation of these materials for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) showed improved performance for the SrTaO 2 N nanoplates, with a record apparent quantum efficiency (AQE) of 6.1 % for OER compared to the polyhedra (AQE: 1.6 %) and SrTaO 2 N polycrystals (AQE: 0.6 %). The enhanced performance from the nanoplates arises from their morphology and lower defect density. These results highlight the importance of developing new synthetic routes to high quality oxynitrides.