This title appears in the Scientific Report :
2019
Please use the identifier:
http://hdl.handle.net/2128/23728 in citations.
Please use the identifier: http://dx.doi.org/10.1002/chem.201901623 in citations.
Nanoscopic Porous Iridium/Iridium Dioxide Superstructures (15 nm): Synthesis and Thermal Conversion by In Situ Transmission Electron Microscopy
Nanoscopic Porous Iridium/Iridium Dioxide Superstructures (15 nm): Synthesis and Thermal Conversion by In Situ Transmission Electron Microscopy
Porous particle superstructures of about 15 nm diameter,consisting of ultrasmall nanoparticles of iridium andiridium dioxide, are prepared through the reduction ofsodium hexachloridoiridate(+IV) with sodium citrate/sodiumborohydride in water. The water-dispersible porous particlescontain about 20 wt...
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Please use the identifier: http://dx.doi.org/10.1002/chem.201901623 in citations.
Porous particle superstructures of about 15 nm diameter,consisting of ultrasmall nanoparticles of iridium andiridium dioxide, are prepared through the reduction ofsodium hexachloridoiridate(+IV) with sodium citrate/sodiumborohydride in water. The water-dispersible porous particlescontain about 20 wt% poly(N-vinylpyrrolidone) (PVP), whichwas added for colloidal stabilization. High-resolution transmissionelectron microscopy confirms the presence of bothiridium and iridium dioxide primary particles (1–2 nm) ineach porous superstructure. The internal porosity(58 vol%) is demonstrated by electron tomography. In situtransmission electron microscopy up to 1000 8C underoxygen, nitrogen, argon/hydrogen (all at 1 bar), and vacuumshows that the porous particles undergo sintering and subsequentcompaction upon heating, a process that starts ataround 250 8C and is completed at around 8008C. Finally,well-crystalline iridium dioxide is obtained under all four environments.The catalytic activity of the as-prepared poroussuperstructures in electrochemical water splitting (oxygenevolution reaction; OER) is reduced considerably upon heatingowing to sintering of the pores and loss of internal surfacearea. |