Boehmite (γ‐AlOOH) nanoparticles: Hydrothermal synthesis, characterization, pH‐controlled morphologies, optical properties, and DFT calculations

Boehmite nanoparticles (γ‐AlOOH) have been successfully synthesized by the hydrothermal method at 180 °C using aluminum nitrate, Al(NO 3 ) 3 ·9H 2 O, as the aluminum source and sodium metaborate, NaBO 2 ·4H 2 O, as controlling agent. The size and morphology of boehmite nanoparticles could be controlled by adjusting the pH value of the reaction mixture. The resulting products were characterized by X‐ray diffraction (XRD), Fourier transform‐infrared spectra (FT‐IR), scanning electron microscopy (SEM), UV–Vis spectra, and photoluminescence spectra. The electronic band structure along with density of states (DOS), obtained at the density functional theory (DFT) level indicates that γ‐AlOOH has a direct energy bandgap of 4.51 eV. The optical properties, including the dielectric, absorption, reflectivity, and energy‐loss spectra of the compound are calculated by the DFT method and analyzed based on the electronic structures.