title: In situ formation of cobalt oxide nanocubanes as efficient oxygen evolution catalysts.
abstract: Oxygen evolution from water poses a significant challenge in solar fuel production because it requires an efficient catalyst to bridge the one-electron photon capture process with the four-electron oxygen evolution reaction (OER). Here, a new strategy was developed to synthesize nonsupported ultrasmall cobalt oxide nanocubanes through an in situ phase transformation mechanism using a layered Co(OH)(OCH3) precursor. Under sonication, the precursor was exfoliated and transformed into cobalt oxide nanocubanes in the presence of NaHCO3-Na2SiF6 buffer solution. The resulting cobalt catalyst with an average particle size less than 2 nm exhibited a turnover frequency of 0.023 per second per cobalt in photocatalytic water oxidation. X-ray absorption results suggested a unique nanocubane structure, where 13 cobalt atoms fully coordinated with oxygen in an octahedral arrangement to form 8 Co4O4 cubanes, which may be responsible for the exceptionally high OER activity.
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Hutchings
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: ‡UNILAB, State Key Lab of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. China.
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.forename: Bryan T
authors.initials: BT
authors.lastname: Yonemoto
authors.affiliation: ‡UNILAB, State Key Lab of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. China.
authors.forename: Xinggui
authors.initials: X
authors.lastname: Zhou
authors.affiliation: ‡UNILAB, State Key Lab of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. China.
authors.forename: Kake
authors.initials: K
authors.lastname: Zhu
authors.forename: Feng
authors.initials: F
authors.lastname: Jiao
mesh_terms: D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D010316:Particle Size; D014867:Water / Q000737:chemistry*
chemical_list: D010087:Oxides; D014867:Water; D003035:Cobalt; D010100:Oxygen; C060728:cobalt oxide