Activation of Osmium by the Surface Effects of Hydrogenated TiO2 Nanotube Arrays for Enhanced Hydrogen Evolution Reaction Performance

Krstajić Pajić MN, Dobrota AS, Mazare AV, Đurđić S, Hwang I, Skorodumova NV, Manojlović D, Vasilić R, Pašti IA, Schmuki P, Lačnjevac U (2023)

Publication Type: Journal article

Publication year: 2023

Journal

ACS Applied Materials and Interfaces American Chemical Society

DOI: 10.1021/acsami.3c04498

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.

Authors with CRIS profile

Anca Valentina Mazare Lehrstuhl für Werkstoffwissenschaften (Korrosion und Oberflächentechnik) Imgon Hwang Lehrstuhl für Werkstoffwissenschaften (Korrosion und Oberflächentechnik) Patrik Schmuki Lehrstuhl für Werkstoffwissenschaften (Korrosion und Oberflächentechnik)

Involved external institutions

University of Belgrade / Универзитет у Београду RS Serbia (RS) Royal Institute of Technology / Kungliga Tekniska Högskolan (KTH) SE Sweden (SE)

How to cite

APA:

Krstajić Pajić, M.N., Dobrota, A.S., Mazare, A.V., Đurđić, S., Hwang, I., Skorodumova, N.V.,... Lačnjevac, U. (2023). Activation of Osmium by the Surface Effects of Hydrogenated TiO2 Nanotube Arrays for Enhanced Hydrogen Evolution Reaction Performance. ACS Applied Materials and Interfaces. https://dx.doi.org/10.1021/acsami.3c04498

MLA:

Krstajić Pajić, Mila N., et al. "Activation of Osmium by the Surface Effects of Hydrogenated TiO2 Nanotube Arrays for Enhanced Hydrogen Evolution Reaction Performance." ACS Applied Materials and Interfaces (2023).

BibTeX: Download