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Technical University of Crete
Technical University of Crete
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EL
| URI: | http://purl.tuc.gr/dl/dias/663E740A-2108-4EC3-9D9B-10183C4B725C | ||
| Year | 2022 | ||
| Type of Item | Peer-Reviewed Journal Publication | ||
| License |
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| Bibliographic Citation | I. A. Poimenidis, N. Papakosta, A. Manousaki, A. Klini, M. Farsari, S. D. Moustaizis, and P. A. Loukakos, “Electrodeposited laser – nanostructured electrodes for increased hydrogen production,” Int. J. Hydrogen Energy, vol. 47, no. 16, pp. 9527-9536, Feb. 2022, doi: 10.1016/j.ijhydene.2022.01.062. https://doi.org/10.1016/j.ijhydene.2022.01.062 | ||
| Appears in Collections |
In the present work, a novel approach has been employed to effectively enlarge the electrocatalytic area of the electrodes in an alkaline electrolysis setup. This approach consists of a two-step electrode fabrication process: In the first step, ultrashort laser pulses have been used to nanostructure the electrode surface. In the second step, electrodeposition of nickel particles was performed in a modified Watt's bath. The resulting electrodes have been found to exhibit a significantly increased hydrogen evolution reaction (HER) activity. Compared to the laser-nanostructured electrode (LN) and an untreated (i.e., flat) electrode, the electrodeposited-laser-nanostructured (ELN) electrode provides (i) enhanced electrochemical values (ii) a significant increase of double-layer capacitance (CDL) (values up to 1945 μF cm−2) compared to that of an LN electrode (288 μF cm−2) (iii) higher Jpeaks at CVs sweeps and (iv) lower Tafel slopes (−121 mV dec−1 compared to −157 mv dec−1). The ELN electrode provides an overpotential value of |η|100 = 264 mV, which shows a noteworthy 34% decrease compared to a flat Ni electrode and a 15% decrease to an (LN) electrode. Scanning electron microscopy (SEM) revealed that the electrodeposition of nickel on the LN nickel electrodes results in a dendrite-like morphology of the surface. Thus, the enhancement of the HER has been attributed to the dendrite-like geometry and the concomitant enlargement of the electrocatalytic area of the electrode, which presents an electrochemical active surface area (ECSA) = 97 cm−2 compared to 2.8 cm−2 of the flat electrode. The electrodes have also been tested in actual hydrogen production condition, and it was found that the ELN electrode produces 4.5 times more hydrogen gas than a flat Ni electrode and 20% more hydrogen gas than an LN electrode (i.e. without the extra nickel electrodeposition).
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