Influence of electronic and optical properties of GaN nanoparticles as potential electrocatalyst in hydrogen production

Due the high electron density of the anion lattice found in nitrides, these compounds have been used for such applications as high power devices, photonics and, more recently, hydrogen production. Among nitride compounds, GaN is well known for its thermal stability, while the different physical techniques used for its synthesis have been reported to obtain different physicochemical properties. However, these techniques are not designed for the mass production of GaN. For these reasons, two different methods for both the chemical synthesis of GaN and its physical chemical characterization are reported in this study, with both synthesis methods presenting wurtzite phase crystallization. Furthermore, both samples presented agglomerates formed by similar sized nanoparticles (~20 nm). Despite the similarity in the particle size, higher pore volume and surface area as well as carbon traces are promoted by the solvothermal route. In contrast, structural and photoluminescence (PL) characterization revealed that Ga vacancies and interstitial N formed in those samples synthesized by the nitridation method, promoting higher intensity in ~2.8 eV PL band. Finally, based on cathodic linear sweep voltammetry, the samples prepared in this study can be considered good candidates for use in hydrogen production.