Nanomaterials for Sustainable Energy in Hydrogen-Fuel Cell: Functionalization and Characterization of Carbon Nano-Semiconductors with Silicon, Germanium, Tin or Lead through Density Functional Theory Study

Abstract

Hydrogen fuel is a promising route to remark on the energy and environmental challenges facing the world today. Therefore, hydrogen storage has become enhancing essential for progressing cleaner and more sustainable technologies. Recent research has recognized metal and metalloid hydrides as a promising alternative that might suggest some benefits over compressed storage. In this work, a profound study on the adsorption of hydrogen by nanocone carbides of main group elements including Si, Ge, Sn and Pb has been done including both geometrical and electronic properties using density functional calculations. The effect of substituting silicon (Si) in silicon carbide by germanium (Ge), tin (Sn) or lead (Pb) elements on the geometrical structure and H atom adsorption behavior were investigated. The results show that when Si atoms are replaced by a Ge, Sn or Pb atoms, the hydrogen adsorption energy is greatly enhanced. Thermochemical, electric and magnetic properties of SiC, GeC, SnC and PbC nanocones and SiC-6H, GeC-6H, SnC-6H and PbC-6H nanocones hydrides are studied by the first-principles methods based on the density functional theory for adsorbing hydrogen atoms. The assumption of the chemical adsorption has been approved by the projected density of states and charge density difference plots. Charge density difference calculations also indicate that the electronic densities were mainly accumulated on the adsorbate of hydrogen atoms. Therefore, these results indicate that the SiC, GeC, SnC and PbC nanocones can be considered as good candidates for hydrogen adsorption and might be helpful for fabricating nano-devices such as hydrogen storage nanomaterials.