Author: ARNAS NAUJOKAITIS
Dissertation title: Hydrothermal synthesis of Molybdenum disulfide (MoS2) heterostructures for the hydrogen evolution from water
Fields of science: Material Engineering T008
Scientific supervisor: dr. Arūnas Jagminas
Defence of the dissertation: June 30, 2022
SUMMARY: Annotation The protection of the environment and utilization of energy is currently the most important challenge to our planet and here the need for clean renewable energy arises. Among alternative energy sources, the development of hydrogen infrastructure would be a major step towards a clean energy future. Hydrogen gas does not exist naturally in nature - it needs to be extracted from natural gas or produced. Nowadays, more than 500 billion cubic meters (or about 45 million tonnes) of hydrogen are extracted worldwide each year. However, 96% of hydrogen is extracted from natural gas, oil, or coal. Thus, the main way to produce hydrogen is still heavily dependent on fossil fuels and does not solve the problem of climate change at all. Electrochemical water splitting is one of the most reliable and effective ways for the sustainable production of pure hydrogen. It is known that platinum and platinum group metals and their derivatives are the most efficient electrocatalysts for hydrogen release from water. However, the practical use of precious metal electrodes is limited by their high cost. In the last decade, electrocatalysts based on carbon, transition metal carbides, nitrides, phosphides, sulfides and selenides capable of splitting water molecules have been intensively researched and developed. One such electrocatalyst is MoS2 – a stable, non-toxic, affordable material, that exhibits great potential in catalysis, sensing, electrochemical operations, and environmentally related fields. MoS2 is a typical transition metal dichalcogenide (TMD) compound with a two-dimensional S−Mo−S triatomic layer structure. It has attracted attention not only because it is capable of catalyzing water and has the greatest potential to replace Pt, but also because it is chemically stable, tunable electronic structure, is easily synthesized, and is inexpensive compared to Pt-based catalysts..