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A Water‐Splitting System with a Cobalt (II,III) Oxide Co‐Catalyst‐Loaded Bismuth Vanadate Photoanode Along with an Organo‐Photocathode
Author(s) -
Murakami Takahiro,
Ikezoi Kosuke,
Nagai Keiji,
Kato Hideki,
Abe Toshiyuki
Publication year - 2020
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.202001271
Subject(s) - bismuth vanadate , photocathode , cobalt , catalysis , bismuth , oxide , water splitting , nanoporous , inorganic chemistry , stoichiometry , materials science , chemistry , chemical engineering , nafion , electrode , electrochemistry , nanotechnology , photocatalysis , electron , metallurgy , biochemistry , physics , quantum mechanics , engineering
In the water‐splitting reaction, the oxidation of water to O 2 is considered to be a kinetically demanding process, so that a co‐catalyst has been usually applied to promote water oxidation. This work demonstrates that, when loading mixed‐valence cobalt (II,III) oxide (Co 3 O 4 ) dispersed in a Nafion membrane (Nf) on a nanoporous bismuth vanadate (BiVO 4 ) photoanode (i. e., BiVO 4 /Nf[Co 3 O 4 ]), stable and efficient water oxidation occurred. In particular, it is noteworthy that the BiVO 4 /Nf[Co 3 O 4 ] photoanode exhibited stable performance even in an acidic medium (pH=2). In the present system consisting of a BiVO 4 /Nf[Co 3 O 4 ] photoanode along with an organo‐photocathode, the stoichiometric formation of O 2 and H 2 successfully occurred by applying just 0.1 V between the photoelectrodes (cf. maximum efficiency, ca. 0.2 %), which was superior to the prototype comprising BiVO 4 and Pt counter electrode. The Co 3 O 4 loading can effectively suppress the collapse of the nanostructured BiVO 4 upon photocorrosion, resulting in the stable and kinetically efficient consumption of holes in BiVO 4 .