Effect of dopants and defect in graphene nanoribbons on dehydrogenation ofMXH4, whereM=Na,LiandX=Al,B

Abstract

Abstract The present paper reports the effect of Graphene Nanoribbons (GNRs) for improving the dehydrogenation of MXH 4 , where M = Na , Li and X = Al , B through density functional calculations. The rectangular Armchair GNRs and ZigZag GNRs with width up to 7.57 A & 10 A and length of 15 A &10 A respectively were considered for the investigation. The effect of dopant and defect was introduced by doping with different dopants ( B , N , Al , Cl and F) and introducing vacancy defect respectively. The MXH 4 interacts with the surface atoms of GNRs with binding energy from 0.31–0.89 eV with AGNR and from 0.26 eV to −1.42 eV with ZGNR respectively. Charge transfer of 0.12–0.26 e take place from GNR surface to MXH 4 molecule resulting in significant decrease in hydrogen release energy ( E HRE ). Doped and defective AGNR lowers E HRE of MXH 4 sharply by 19–56% whereas ZGNR decreases E HRE by 18–70% respectively. The results agree qualitatively with the available experimental result and outline the importance of nano carbon as a catalyst for improving the performance of light complex metal hydride systems.