Hydrogen Adsorption Mechanism of SiC Nanocones

Abstract

Due to rapid depletion of fossil energy sources and increasing the environmental pollution through high fossil energy consumption, an alternative renewable and clean energy carrier as hydrogen is requested more investigations in order to get the optimal request by DOE. In this study, a deepest study on SiC nanocones is done including both of the geometrical and electronic properties of all possible five different disclination angles as a function of size using density functional (DFT) calculations at the B3LYP/6-31g level of theory. Then the hydrogen adsorption mechanism is investigated on three different sites: HS1 (above the first neighbor atom of the apex atoms), HS2 (above one atom of the apex atoms) and HS3 (above one atom far from the apex atoms). Our calculations show that the most candidate SiC nanocone structure for hydrogen storage is Si41N49H10-HS2-M1-Type 2 with disclination angle 300˚. In addition, our results indicate that the hydrogen adsorption induced the energy gap to decrease. Hence, these results indicate that the SiCNCs can be considered as a good candidate for hydrogen storage.