TY  - JOUR
AU  - Krstajić Pajić, Mila N.
AU  - Dobrota, Ana S.
AU  - Mazare, Anca
AU  - Đurđić, Slađana Z.
AU  - Hwang, Imgon
AU  - Skorodumova, Natalia V.
AU  - Manojlović, Dragan D.
AU  - Vasilić, Rastko
AU  - Pašti, Igor A.
AU  - Schmuki, Patrik
AU  - Lačnjevac, Uroš
PY  - 2023
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/6277
AB  - Efficient cathodes for the hydrogen evolution reaction (HER) in acidic water electrolysis rely on the use of expensive platinum group metals (PGMs). However, to achieve economically viable operation, both the content of PGMs must be reduced and their intrinsically strong H adsorption mitigated. Herein, we show that the surface effects of hydrogenated TiO2 nanotube (TNT) arrays can make osmium, a so far less-explored PGM, a highly active HER electrocatalyst. These defect-rich TiO2 nanostructures provide an interactive scaffold for the galvanic deposition of Os particles with modulated adsorption properties. Through systematic investigations, we identify the synthesis conditions (OsCl3 concentration/temperature/reaction time) that yield a progressive improvement in Os deposition rate and mass loading, thereby decreasing the HER overpotential. At the same time, the Os particles deposited by this procedure remain mainly sub-nanometric and entirely cover the inner tube walls. An optimally balanced Os@TNT composite prepared at 3 mM/55 °C/30 min exhibits a record low overpotential (η) of 61 mV at a current density of 100 mA cm–2, a high mass activity of 20.8 A mgOs–1 at 80 mV, and a stable performance in an acidic medium. Density functional theory calculations indicate the existence of strong interactions between the hydrogenated TiO2 surface and small Os clusters, which may weaken the Os–H* binding strength and thus boost the intrinsic HER activity of Os centers. The results presented in this study offer new directions for the fabrication of cost-effective PGM-based catalysts and a better understanding of the synergistic electronic interactions at the PGM|TiO2 interface.
PB  - American Chemical Society
T2  - ACS Applied Materials & Interfaces
T1  - Activation of Osmium by the Surface Effects of Hydrogenated TiO2 Nanotube Arrays for Enhanced Hydrogen Evolution Reaction Performance
VL  - 15
IS  - 26
SP  - 31459
EP  - 31469
DO  - 10.1021/acsami.3c04498
ER  - 

@article{
author = "Krstajić Pajić, Mila N. and Dobrota, Ana S. and Mazare, Anca and Đurđić, Slađana Z. and Hwang, Imgon and Skorodumova, Natalia V. and Manojlović, Dragan D. and Vasilić, Rastko and Pašti, Igor A. and Schmuki, Patrik and Lačnjevac, Uroš",
year = "2023",
abstract = "Efficient cathodes for the hydrogen evolution reaction (HER) in acidic water electrolysis rely on the use of expensive platinum group metals (PGMs). However, to achieve economically viable operation, both the content of PGMs must be reduced and their intrinsically strong H adsorption mitigated. Herein, we show that the surface effects of hydrogenated TiO2 nanotube (TNT) arrays can make osmium, a so far less-explored PGM, a highly active HER electrocatalyst. These defect-rich TiO2 nanostructures provide an interactive scaffold for the galvanic deposition of Os particles with modulated adsorption properties. Through systematic investigations, we identify the synthesis conditions (OsCl3 concentration/temperature/reaction time) that yield a progressive improvement in Os deposition rate and mass loading, thereby decreasing the HER overpotential. At the same time, the Os particles deposited by this procedure remain mainly sub-nanometric and entirely cover the inner tube walls. An optimally balanced Os@TNT composite prepared at 3 mM/55 °C/30 min exhibits a record low overpotential (η) of 61 mV at a current density of 100 mA cm–2, a high mass activity of 20.8 A mgOs–1 at 80 mV, and a stable performance in an acidic medium. Density functional theory calculations indicate the existence of strong interactions between the hydrogenated TiO2 surface and small Os clusters, which may weaken the Os–H* binding strength and thus boost the intrinsic HER activity of Os centers. The results presented in this study offer new directions for the fabrication of cost-effective PGM-based catalysts and a better understanding of the synergistic electronic interactions at the PGM|TiO2 interface.",
publisher = "American Chemical Society",
journal = "ACS Applied Materials & Interfaces",
title = "Activation of Osmium by the Surface Effects of Hydrogenated TiO2 Nanotube Arrays for Enhanced Hydrogen Evolution Reaction Performance",
volume = "15",
number = "26",
pages = "31459-31469",
doi = "10.1021/acsami.3c04498"
}

Krstajić Pajić, M. N., Dobrota, A. S., Mazare, A., Đurđić, S. Z., Hwang, I., Skorodumova, N. V., Manojlović, D. D., Vasilić, R., Pašti, I. A., Schmuki, P.,& Lačnjevac, U.. (2023). Activation of Osmium by the Surface Effects of Hydrogenated TiO2 Nanotube Arrays for Enhanced Hydrogen Evolution Reaction Performance. in ACS Applied Materials & Interfaces
American Chemical Society., 15(26), 31459-31469.
https://doi.org/10.1021/acsami.3c04498

Krstajić Pajić MN, Dobrota AS, Mazare A, Đurđić SZ, Hwang I, Skorodumova NV, Manojlović DD, Vasilić R, Pašti IA, Schmuki P, Lačnjevac U. Activation of Osmium by the Surface Effects of Hydrogenated TiO2 Nanotube Arrays for Enhanced Hydrogen Evolution Reaction Performance. in ACS Applied Materials & Interfaces. 2023;15(26):31459-31469.
doi:10.1021/acsami.3c04498 .

Krstajić Pajić, Mila N., Dobrota, Ana S., Mazare, Anca, Đurđić, Slađana Z., Hwang, Imgon, Skorodumova, Natalia V., Manojlović, Dragan D., Vasilić, Rastko, Pašti, Igor A., Schmuki, Patrik, Lačnjevac, Uroš, "Activation of Osmium by the Surface Effects of Hydrogenated TiO2 Nanotube Arrays for Enhanced Hydrogen Evolution Reaction Performance" in ACS Applied Materials & Interfaces, 15, no. 26 (2023):31459-31469,
https://doi.org/10.1021/acsami.3c04498 . .