V<sub>2</sub>N MXene for Hydrogen Storage: First-Principles Calculations
Sunita Saharan, Umesh Ghanekar, Shweta Meena
Abstract
Hydrogen has emerged as a green and sustainable alternative renewable energy source for fuel cells. Recently, MXenes have been proposed as versatile materials for hydrogen storage and various energy-related applications. Herein, monolayer and bilayer V 2 N MXenes have been studied for hydrogen storage performances through first-principles computations. The structural stability and electronic properties like bandgap and density of states of V 2 N MXene are first investigated using density functional theory calculations. Monolayered V 2 N MXene exhibits average adsorption energy between −0.80 and −0.32 eV, whereas bilayered V 2 N shows values between +0.27 and −0.35 eV for Y and Z adsorption sites. Further, Kubas interaction has been observed for both MXene structures at Y and Z sites through adsorption energy and projected density of states analyses. The calculated gravimetric storage capacity for monolayer and bilayer V 2 N is 6.86 and 5.45 wt %, respectively. All of the H 2 adsorbed on both monolayer and bilayer V 2 N MXene structures is exclusively attributed to the Kubas interaction. This finding indicates that the reversible capacity for hydrogen storage in the V 2 N monolayer is 6.86 wt %, while for the V 2 N bilayer, it is 5.45 wt %. These findings indicate that V 2 N MXene exhibits strong potential as a versatile material for hydrogen storage.