TY - JOUR
T1 - Ultrasmall dispersible crystalline nickel oxide nanoparticles as high-performance catalysts for electrochemical water splitting
AU - Fominykh, Ksenia
AU - Feckl, Johann M.
AU - Sicklinger, Johannes
AU - Döblinger, Markus
AU - Böcklein, Sebastian
AU - Ziegler, Jurgen
AU - Peter, Laurence
AU - Rathousky, Jiri
AU - Scheidt, Ernst-Wilhelm
AU - Bein, Thomas
AU - Fattakhova-Rohlfing, Dina
PY - 2014/6/4
Y1 - 2014/6/4
N2 - Ultrasmall, crystalline, and dispersible NiO nanoparticles are prepared for the first time, and it is shown that they are promising candidates as catalysts for electrochemical water oxidation. Using a solvothermal reaction in tert-butanol, very small nickel oxide nanocrystals can be made with sizes tunable from 2.5 to 5 nm and a narrow particle size distribution. The crystals are perfectly dispersible in ethanol even after drying, giving stable transparent colloidal dispersions. The structure of the nanocrystals corresponds to phase-pure stoichiometric nickel(ii) oxide with a partially oxidized surface exhibiting Ni(iii) states. The 3.3 nm nanoparticles demonstrate a remarkably high turn-over frequency of 0.29 s at an overpotential of g = 300 mV for electrochemical water oxidation, outperforming even expensive rare earth iridium oxide catalysts. The unique features of these NiO nanocrystals provide great potential for the preparation of novel composite materials with applications in the field of (photo)electrochemical water splitting. The dispersed colloidal solutions may also find other applications, such as the preparation of uniform hole-conducting layers for organic solar cells.
AB - Ultrasmall, crystalline, and dispersible NiO nanoparticles are prepared for the first time, and it is shown that they are promising candidates as catalysts for electrochemical water oxidation. Using a solvothermal reaction in tert-butanol, very small nickel oxide nanocrystals can be made with sizes tunable from 2.5 to 5 nm and a narrow particle size distribution. The crystals are perfectly dispersible in ethanol even after drying, giving stable transparent colloidal dispersions. The structure of the nanocrystals corresponds to phase-pure stoichiometric nickel(ii) oxide with a partially oxidized surface exhibiting Ni(iii) states. The 3.3 nm nanoparticles demonstrate a remarkably high turn-over frequency of 0.29 s at an overpotential of g = 300 mV for electrochemical water oxidation, outperforming even expensive rare earth iridium oxide catalysts. The unique features of these NiO nanocrystals provide great potential for the preparation of novel composite materials with applications in the field of (photo)electrochemical water splitting. The dispersed colloidal solutions may also find other applications, such as the preparation of uniform hole-conducting layers for organic solar cells.
KW - electrocatalysis
KW - nickel oxide
KW - nanocrystals
KW - solvothermal synthesis
KW - water splitting
U2 - 10.1002/adfm.201303600
DO - 10.1002/adfm.201303600
M3 - Article
SN - 1616-301X
VL - 24
SP - 3123
EP - 3129
JO - Advanced Functional Materials
JF - Advanced Functional Materials
IS - 21
ER -