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AuthorJiang, C.
AuthorMoniz, S.J.A.
AuthorKhraisheh, M.
AuthorTang, J.
Available date2016-02-15T09:42:42Z
Publication Date2014-09
Publication NameChemistry - A European Journal
ResourceScopus
CitationJiang, C., Moniz, S.J.A., Khraisheh, M., Tang, J. "Earth-abundant oxygen evolution catalysts coupled onto ZnO nanowire arrays for efficient photoelectrochemical water cleavage," (2014) Chemistry - A European Journal, 20 (40), pp. 12954-12961.
ISSN0947-6539
URIhttp://dx.doi.org/10.1002/chem.201403067
URIhttp://hdl.handle.net/10576/4142
AbstractZnO has long been considered as a model UV-driven photoanode for photoelectrochemical water splitting, but its performance has been limited by fast charge-carrier recombination, extremely poor stability in aqueous solution, and slow kinetics of water oxidation. These issues were addressed by applying a strategy of optimization and passivation of hydrothermally grown 1D ZnO nanowire arrays. The length and diameter of bare ZnO nanowires were optimized by varying the growth time and precursor concentration to achieve optimal photoelectrochemical performance. The addition of earth-abundant cobalt phosphate (Co-Pi) and nickel borate (Ni-B) oxygen evolution catalysts onto ZnO nanowires resulted in substantial cathodic shifts in onset potential to as low as about 0.3 V versus the reversible hydrogen electrode (RHE) for Ni-B/ZnO, for which a maximum photocurrent density of 1.1 mA cm-2 at 0.9 V (vs. RHE) with applied bias photon-to-current efficiency of 0.4 % and an unprecedented near-unity incident photon-to-current efficiency at 370 nm. In addition the potential required for saturated photocurrent was dramatically reduced from 1.6 to 0.9 V versus RHE. Furthermore, the stability of these ZnO nanowires was significantly enhanced by using Ni-B compared to Co-Pi due to its superior chemical robustness, and it thus has additional functionality as a stable protecting layer on the ZnO surface. These remarkable enhancements in both photocatalytic activity and stability directly address the current severe limitations in the use of ZnO-based photoelectrodes for water-splitting applications, and can be applied to other photoanodes for efficient solar-driven fuel synthesis.
SponsorChina Scholarship Council (CSC File No. 201308060090). European Community Seventh Frame work Programme (4G-PHOTOCAT 309636). Qatar National Research Fund under its National Priorities Research Program Award No. NPRP 09-328-2-22.
Languageen
PublisherWiley-VCH Verlag
Subjectelectrochemistry
nanostructures
photochemistry
thin films
water splitting
TitleEarth-abundant oxygen evolution catalysts coupled onto ZnO nanowire arrays for efficient photoelectrochemical water cleavage
TypeArticle
Pagination12954-12961
Issue Number40
Volume Number20
dc.accessType Open Access


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