Promotion of H2 adsorption performance on InN monolayer by embedding Cu atom: A first-principles study

Hydrogen energy as a clean energy has great application potential, and finding efficient hydrogen storage materials has become the current research hotspot. This work studied the structure, electronic properties, thermodynamic properties and H₂ adsorption performance of InN, N-defect (V_N–InN), In-defect (V_In–InN), Cu atom substitutes N atom embedded InN (Cu/V_N–InN) and Cu atom substitutes In atom embedded InN (Cu/V_In–InN) by density functional theory (DFT). The results show that all of the five InN materials have good thermal stability at room temperature (300 K), and the structural stability of the defective InN increases after embedding of Cu atom. Meanwhile, the hydrogen interaction on the five InN materials was investigated. Cu/V_In–InN has the best performance for H₂ adsorption among the five InN materials. The adsorption energy for Cu/V_In–InN can reach ?0.769 eV, which is 4.5 times better than original InN nanosheet. After adsorbing 5H₂ molecules, the average adsorption energy is ?0.399 eV that indicates Cu/V_In–InN structure still has possibility of adsorbing more hydrogen molecules and it has the potential to become a new hydrogen storage material.