TY - JOUR
T1 - Surface and structural characterization of Cu-exchanged hydroxyapatites and their application in H2O2 electrocatalytic reduction
AU - Escolano Casado, Guillermo
AU - Ivanchenko, Pavlo
AU - Paul, Geo
AU - Bisio, Chiara
AU - Marchese, Leonardo
AU - Ashrafi, Amir M.
AU - Milosavljevic, Vedran
AU - Degli Esposti, Lorenzo
AU - Iafisco, Michele
AU - Mino, Lorenzo
N1 - Publisher Copyright:
© 2022 Elsevier B.V.
PY - 2022/9/1
Y1 - 2022/9/1
N2 - We report on the preparation of hydroxyapatite (HA) nanoparticles with high specific surface area, terminated with calcium-rich {0 1 0} facets, and their subsequent surface functionalization with copper by cationic exchange with copper nitrate solutions at different concentrations. Elemental analysis highlighted a progressive increase of the amount of copper incorporated into the HA, reaching a maximum of ∼ 7 wt%. A combined X-ray diffraction and solid-state NMR investigation showed no significant structural differences after the Cu functionalization, confirming that the copper exchange occurs mainly at the surface until saturation and, for the higher Cu concentrations, also in the sub-surface/bulk layers of the material, without altering the HA crystal structure. The gradual substitution of surface Ca2+ by Cu2+ was studied also by IR spectroscopy using carbon monoxide as probe molecule. Finally, we assessed the catalytic activity of the materials testing the electrochemical reduction of H2O2 by cyclic voltammetry. We observed a progressive increase in catalytic activity correlated with the amount of Cu, suggesting the possible application of copper-exchanged HA as electrochemical H2O2 sensors.
AB - We report on the preparation of hydroxyapatite (HA) nanoparticles with high specific surface area, terminated with calcium-rich {0 1 0} facets, and their subsequent surface functionalization with copper by cationic exchange with copper nitrate solutions at different concentrations. Elemental analysis highlighted a progressive increase of the amount of copper incorporated into the HA, reaching a maximum of ∼ 7 wt%. A combined X-ray diffraction and solid-state NMR investigation showed no significant structural differences after the Cu functionalization, confirming that the copper exchange occurs mainly at the surface until saturation and, for the higher Cu concentrations, also in the sub-surface/bulk layers of the material, without altering the HA crystal structure. The gradual substitution of surface Ca2+ by Cu2+ was studied also by IR spectroscopy using carbon monoxide as probe molecule. Finally, we assessed the catalytic activity of the materials testing the electrochemical reduction of H2O2 by cyclic voltammetry. We observed a progressive increase in catalytic activity correlated with the amount of Cu, suggesting the possible application of copper-exchanged HA as electrochemical H2O2 sensors.
KW - Copper-exchanged hydroxyapatites
KW - FTIR spectroscopy
KW - electrocatalysis
KW - electrochemical HO sensors
KW - solid-state NMR
UR - http://www.scopus.com/inward/record.url?scp=85129731289&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2022.153495
DO - 10.1016/j.apsusc.2022.153495
M3 - Article
SN - 0169-4332
VL - 595
JO - Applied Surface Science
JF - Applied Surface Science
M1 - 153495
ER -