Photoelectrochemical properties of SrNbO2N photoanodes for water oxidation fabricated by the particle transfer method

Faraday Discuss. 2014:176:213-23. doi: 10.1039/c4fd00122b. Epub 2014 Nov 19.

Abstract

SrNbO(2)N photoanodes, which have a band gap energy of 1.8 eV, were tested for photoelectrochemical water oxidation in water splitting. The photoanodes were fabricated either by a particle transfer method or an electrophoretic deposition method. The effects of the precursors, fabrication method, and CoOx catalyst loading were studied in order to identify the shortcomings of the photoanodes and improve their photoelectrochemical properties for water oxidation. SrNbO(2)N photoanodes fabricated by particle transfer generated a photocurrent that was one order of magnitude higher than that of photoanodes prepared via electrophoretic deposition. The stoichiometric oxide precursor (Sr(2)Nb(2)O(7)) was found to be preferable to the Sr-rich oxide precursor (Sr(5)Nb(4)O(15)). CoOx increased the photoanodic current on SrNbO(2)N photoelectrodes. Nevertheless, the incident photon-to-current efficiency was still limited to 10% at most. Potential problems with SrNbO(2)N photoanodes were discussed.