Nanosensor of gallium nitride for methanol adsorption for producing hydrogen: A computational chemistry study

Abstract

The selective hydrogen production from methanol on the graphitic-like gallium nitride (GaN) and carbon doped gallium nitride (C–GaN) nanosheets has been challenged using the density functional theory (DFT) method. In this work, we report that GaN and C-doped GaN can catalyze the direct producing hydrogen (H2) of methanol (CH3OH) through Langmuir adsorption. The changes of charge density have shown a more important charge transfer for C-doped GaN compared to GaN which act both as the electron acceptor while CH3OH molecules in water act as the stronger electron donors through adsorption on the GaN and C-doped GaN surfaces. The adsorption of CH3OH molecules on the GaN and C-doped GaN surfaces represented spin polarization in the GaN and C-doped GaN which can be employed as thee magnetic sensors for running the reaction of H2 producing. The partial electron density states based on “PDOS” graphs have explained that the CH3OH states in both of GaN and C-doped GaN nanosheets, respectively, have more conduction bands between −5 eV to −10 eV. The simulated distribution functions of CH3O@GaN and CH3O@C–GaN complexes exhibits that the bond lengths of O–Ga in CH3O–GaN complex is 1.99 Å and O–C in CH3O–C–GaN complex is 1.43 Å. Besides, the plot for electric potential versus atomic charge has been shown around carbon doping of the GaN which presents the electron accepting characteristics of this element via the electron donor of oxygen atom of hydroxyl group in CH3OH with linear relation coefficient of R2 = 0.9948. GaN and C–GaN nanosheets seem to have enough efficiency for adsorption CH3OH molecules through charge transfer from oxygen to the gallium and carbon elements due to intra-atomic and interatomic interactions.