First-principles calculations of hydrogen generation due to water splitting on polar GaN surfaces
Journal
Journal of Physical Chemistry C
Journal Volume
114
Journal Issue
42
Pages
18228-18232
Date Issued
2010
Author(s)
Abstract
We present the chemical reactions leading to hydrogen gas generation via water splitting on polar GaN surfaces, which can be a significant source of renewable energy. To build an understanding at the atomic level of the activations afforded by the GaN (0001) and (0001̄) surfaces, we determine the reaction mechanism of hydrogen generation on the polar faces using density functional theory calculations. The calculation results show that the first H splitting from water can occur with ground-state electronic structures; the barriers of H2O splitting are 0.10 and 0.34 eV on the Ga-face and the N-face, respectively. However, the second H splitting requires huge energies of 1.42 and 1.73 eV, respectively, on the Ga-face and the N-face. Although the polar GaN surface can catalyze the first hydrogen splitting from water, we suggest that photoexcitation should be necessary for the second splitting. © 2010 American Chemical Society.
SDGs
Other Subjects
Atomic levels; Density functional theory calculations; First-principles calculation; Hydrogen gas generation; Hydrogen generations; Hydrogen splitting; Reaction mechanism; Renewable energies; Water splitting; Density functional theory; Electronic structure; Gallium alloys; Gallium nitride; Photoexcitation; Renewable energy resources; Hydrogen production
Type
journal article