Ioannis Poimenidis, "Hydrogen production through nanotechnology ", Doctoral Dissertation, School of Production Engineering and Management, Technical University of Crete, Chania, Greece, 2022
https://doi.org/10.26233/heallink.tuc.92300
The future energy requirements are impossible to meet through existing energy production methods. New innovative and environmentally friendly forms of energy need to be invented and implemented immediately. An environmentally friendly method of energy production is the energy that can be obtained from hydrogen. The present thesis deals diligently with the increase of hydrogen production through the fabrication of nanostructured electrodes and their use in alkaline electrolysis. The primary study of this thesis is the Hydrogen Evolution Reaction (HER) and how the fabricated nanostructured surfaces improve the reaction efficiency. This thesis has the following research objectives: i. The development of a new method of fabricating electrodes with resistance in alkaline solutions by a relatively straightforward process, ii. The creation of nanostructures using short-term laser pulses on the substrate of Ni and Fe electrodes to increase their electrocatalytically active surface, iii. The additional increase of the electrocatalytic surface of the laser nanostructured surfaces with electrodeposition of Ni particles, iv. The enhancement of hydrogen production of the nanostructured electrodes, v. The creation of a setup for measuring the produced hydrogen, which may be subject to changes depending on the size of the electrodes. At the same time, with the application of short-term laser pulses for the reconstruction of surfaces and the creation of electrodes for their use in HER, there is a possibility of creating complex architectural forms on the substrate with high adsorption for subsequent particle deposition. The results obtained in the experimental part show that the laser-nanostructured nickel electrodes increased the hydrogen production up to 4.5 times compared to a non-nanostructured nickel electrode. Moreover, the fabricated laser-nanostructured iron electrode increased hydrogen production by up to 50% compared to an untreated iron electrode. The nanostructured nickel and iron electrodes may also be used as cathode and anode for a newly-improved iron-nickel battery In addition, all the obtained electrochemical measurements confirm that the produced nickel electrodes can be used in small and large-scale applications, as they show high stability and much improved current dynamics, similar to industrial electrolyzers. Also, the fabricated electrodes' increased double-layer capacitance (CDL) can depict their use as "supercapacitors."