Atomistic Modelling of Low Dimensional Materials for Energy Harvesting and Gas Sensing Applications

Sammanfattning: Energy crisis and pollution are the two biggest issues of the present times which are extremely important to address on priority. Scientists/Researchers are trying to explore and create alternate means of energy production which are sustainable and free from greenhouse emissions. Use of the hydrogen (H2) as an energy carrier can promise energy sustainability, economic viability, and environmental friendliness. H2 is abundant in nature and delivers the highest energy density compared to all types of fossil fuels. However, the gaseous nature of the H2 makes its storage difficult for practical applications. Previously employed H2 storage strategies (liquefaction and pressurized storage) suffer from economic and safety concerns. H2 storage in solid-state materials via non-dissociative adsorption is the most suitable technique. However, adsorption energies of the H2 with the storage medium are typically very weak therefore operations under ambient working conditions are not possible. We used density functional theory to design the H2 storage media, which are capable to adsorb H2 in a non-dissociative manner with high gravimetric capacity and adequate adsorption energies for storage under the ambient conditions. Our findings point to the fact that the H2 adsorption on the functionalized nanostructures is the most efficient approach for the materials based storage. Furthermore, for environmental safety and monitoring perspective, we investigated and proposed novel two-dimensional nanomaterials that are capable to sense and capture hazardous gases from the environment. In short, this thesis work is an attempt towards designing efficient materials for H2 based energy harvesting and gas sensing applications.