Hydrogen adsorption on zigzag (4,0), (5,0) and (6,0) hg-C3N4-NTs and their surfaces decorated by selected-elements (periods 3 and 4): A DFT study

Abstract

The adsorption of selected elements from periods 3 (Al, Si, P, and S) and 4 (Ga, Ge, As, and Se) on the surfaces of (4,0), (5,0), and (6,0) hg-C3N4-NTs was investigated using the periodic-DFT method at the PBEPBE/6-31G(d) level. The H2 molecule adsorption on S-decorated (4,0) hg-C3N4-NTs exhibited the strongest adsorption, with a physical adsorption energy of −1.34 eV. The Al-decorated (5,0) and (6,0) hg-C3N4-NTs demonstrated the highest hydrogen molecule adsorption abilities, with chemical adsorption energies of −1.28 eV and −1.28 eV, respectively. Our results found that all Al-, Si-, P-, S-, Ga-, Ge-, As-, and Se-decorated (4,0), (5,0), and (6,0) hg-C3N4-NTs show potential as hydrogen storage materials. Furthermore, As-decorated (4,0), (5,0), and (6,0) hg-C3N4-NTs exhibit promising characteristics for hydrogen detection.