Femtosecond Laser-Ablated Copper Surface as a Substrate for a MoS2-Based Hydrogen Evolution Reaction Electrocatalyst

Autor: Levinas Ramunas, Grigucevičienė Asta, Kubilius Tadas, Matijošius Aidas, Tamašauskaitė-Tamašiūnaitė Loreta, Cesiulis Henrikas, Norkus Eugenijus
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Materials; Volume 15; Issue 11; Pages: 3926
Materials
Materials, Basel : MDPI AG, 2022, vol. 15, iss. 11, art. no. 3926, p. 1-20
ISSN: 1996-1944
DOI: 10.3390/ma15113926
Popis: One of the methods to improve the performance of a heterogeneous electrocatalyst is the dispersion of a catalytic material on a suitable substrate. In this study, femtosecond laser ablation was used to prepare very rough but also ordered copper surfaces consisting of vertical, parallel ridges. Then, a molybdenum sulfide coating was electrochemically deposited onto these surfaces. It was observed by profilometry that the average roughness of the surface after coating with MoS2had decreased, but the developed surface area still remained significantly larger than the projected surface area. The electrodes were then used as an electrocatalyst for the hydrogen evolution reaction in acidic media. These were highly efficient, reaching 10 mA cm−2of HER current at a −181 mV overpotential and a Tafel slope of ~39 mV dec−1. Additionally, scanning electrochemical microscopy was used to observe whether hydrogen evolution would preferentially occur in certain spots, for example, on the peaks, but the obtained results suggest that the entire surface is active. Finally, the electrochemical impedance spectroscopy data showed the difference in the double-layer capacitance between the ablated and non-ablated surfaces (up to five times larger) as well as the parameters that describe the improved catalytic activity of fs-Cu/MoS2electrodes.
Databáze: OpenAIRE
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