High-performance hydrogen evolution electrocatalysis using proton-intercalated TiO2 nanotube arrays as interactive supports for Ir nanoparticles
| Autor: | Natalia V. Skorodumova, Ondřej Tomanec, N.R. Elezović, Slađana Đurđić, Igor A. Pašti, Shiva Mohajernia, Patrik Schmuki, Uroš Lačnjevac, Radek Zbořil, Dragan Manojlović, Rastko Vasilić, Nhat Truong Nguyen, Ana S. Dobrota |
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| Rok vydání: | 2020 |
| Předmět: |
Electrolysis
Materials science Hydrogen Renewable Energy Sustainability and the Environment chemistry.chemical_element Nanoparticle 02 engineering and technology General Chemistry Overpotential 010402 general chemistry 021001 nanoscience & nanotechnology Electrocatalyst 01 natural sciences Cathode 0104 chemical sciences Catalysis law.invention Metal chemistry Chemical engineering law visual_art visual_art.visual_art_medium General Materials Science 0210 nano-technology |
| Zdroj: | Journal of Materials Chemistry A |
| ISSN: | 2050-7496 2050-7488 |
| DOI: | 10.1039/d0ta07492f |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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