Lačnjevac U, Vasilić R, Dobrota A, Đurđić S, Tomanec O, Zbořil R, Mohajernia S, Nguyen NT, Skorodumova N, Manojlović D, Elezović N, Pašti I, Schmuki P (2020)
Publication Type: Journal article
Publication year: 2020
Book Volume: 8
Pages Range: 22773-22790
Journal Issue: 43
DOI: 10.1039/d0ta07492f
Developing ultraefficient electrocatalytic materials for the hydrogen evolution reaction (HER) with low content of expensive platinum group metals (PGMs) via low-energy-input procedures is the key to the successful commercialization of green water electrolysis technologies for sustainable production of high-purity hydrogen. In this study, we report a facile room-temperature synthesis of ultrafine metallic Ir nanoparticles on conductive, proton-intercalated TiO2 nanotube (H-TNT) arrays via galvanic displacement. A series of experiments demonstrate that a controlled transformation of the H-TNT surface microstructure from neat open-top tubes to disordered nanostripe bundles ("nanograss") is highly beneficial for providing an abundance of exposed Ir active sites. Consequently, for nanograss-engineered composites, outstanding HER activity metrics are achieved even at very low Ir(iii) precursor concentrations. An optimum Ir@TNT cathode loaded with 5.7 μgIr cm-2 exhibits an overpotential of -63 mV at -100 mA cm-2 and a mass activity of 34 A mgIr-1 at -80 mV under acidic conditions, along with excellent catalytic durability and structural integrity. Density functional theory (DFT) simulations reveal that the hydrogen-rich TiO2 surface not only stabilizes the deposited Ir and weakens its H binding strength to a moderate intensity, but also actively takes part in the HER mechanism by refreshing the Ir catalytic sites near the Ir|H-TiO2 interface, thus substantially promoting H2 generation. The comprehensive characterization combined with theory provides an in-depth understanding of the electrocatalytic behavior of H-TNT supported PGM nanoparticles and demonstrates their high potential as competitive electrocatalyst systems for the HER. This journal is
APA:
Lačnjevac, U., Vasilić, R., Dobrota, A., Đurđić, S., Tomanec, O., Zbořil, R.,... Schmuki, P. (2020). High-performance hydrogen evolution electrocatalysis using proton-intercalated TiO2nanotube arrays as interactive supports for Ir nanoparticles. Journal of Materials Chemistry A, 8(43), 22773-22790. https://doi.org/10.1039/d0ta07492f
MLA:
Lačnjevac, Uroš, et al. "High-performance hydrogen evolution electrocatalysis using proton-intercalated TiO2nanotube arrays as interactive supports for Ir nanoparticles." Journal of Materials Chemistry A 8.43 (2020): 22773-22790.
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