TY - JOUR
T1 - Electrocatalytic Oxidation of Water by OH−- and H2O-Capped IrOx Nanoparticles Electrophoretically Deposited on Graphite and Basal Plane HOPG
T2 - Effect of the Substrate Electrode**
AU - Mirbagheri, Naghmehalsadat
AU - Campos, Rui
AU - Ferapontova, Elena E.
N1 - Publisher Copyright:
© 2021 Wiley-VCH GmbH
PY - 2021/5
Y1 - 2021/5
N2 - Iridium oxide (IrOx) is one of the most efficient electrocatalysts for water oxidation reaction (WOR). Here, WOR electrocatalysis by 1.6 nm IrOx nanoparticles (NPs) electrophoretically deposited onto spectroscopic graphite (Gr) and basal plane highly ordered pyrolytic graphite (HOPG) was studied as a function of NPs’ capping ligands and electrodeposition substrate. On Gr, OH−- and H2O-capped NPs exhibited close sub-monolayer surface coverages and specific electrocatalytic activity of 18.9-23.5 mA nmol−1 of IrIV/V sites, at 1 V and pH 7. On HOPG, OH−-capped NPs produced films with a diminished WOR activity of 5.17±2.40 mA nmol−1. Electro-wettability-induced changes impeded electrophoretic deposition of H2O-capped NPs on HOPG, WOR currents being 25-fold lower than observed for OH−-capped ones. The electrocatalysis efficiency correlated with hydrophilic properties of the substrate electrodes, affecting morphological and as a result catalytic properties of the formed IrOx films. These results, important both for studied and related carbon nanomaterials systems, allow fine-tuning of electrocatalysis by a proper choice of the substrate electrode.
AB - Iridium oxide (IrOx) is one of the most efficient electrocatalysts for water oxidation reaction (WOR). Here, WOR electrocatalysis by 1.6 nm IrOx nanoparticles (NPs) electrophoretically deposited onto spectroscopic graphite (Gr) and basal plane highly ordered pyrolytic graphite (HOPG) was studied as a function of NPs’ capping ligands and electrodeposition substrate. On Gr, OH−- and H2O-capped NPs exhibited close sub-monolayer surface coverages and specific electrocatalytic activity of 18.9-23.5 mA nmol−1 of IrIV/V sites, at 1 V and pH 7. On HOPG, OH−-capped NPs produced films with a diminished WOR activity of 5.17±2.40 mA nmol−1. Electro-wettability-induced changes impeded electrophoretic deposition of H2O-capped NPs on HOPG, WOR currents being 25-fold lower than observed for OH−-capped ones. The electrocatalysis efficiency correlated with hydrophilic properties of the substrate electrodes, affecting morphological and as a result catalytic properties of the formed IrOx films. These results, important both for studied and related carbon nanomaterials systems, allow fine-tuning of electrocatalysis by a proper choice of the substrate electrode.
KW - basal plane highly ordered pyrolytic graphite (HOPG)
KW - electrocatalysis
KW - graphite
KW - iridium oxide nanoparticles
KW - water oxidation reaction
UR - http://www.scopus.com/inward/record.url?scp=85108291028&partnerID=8YFLogxK
U2 - 10.1002/celc.202100317
DO - 10.1002/celc.202100317
M3 - Journal article
AN - SCOPUS:85108291028
SN - 2196-0216
VL - 8
SP - 1632
EP - 1641
JO - ChemElectroChem
JF - ChemElectroChem
IS - 9
ER -