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

Abstract

Boehmite nanoparticles (g-AlOOH) have been successfully synthesized by the hydrothermal method at 180 8C using aluminum nitrate, Al(NO 3 ) 3 Á9H 2 O, as the aluminum source and sodium metaborate, NaBO 2 Á4H 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 g-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.

Precipitation of spherical boehmite from concentrated sodium aluminate solution by adding gibbsite as seed

“…The precipitation of gibbsite or boehmite does not generate waste water and enables the low-cost preparation of sodium aluminate solution. Moreover, boehmite with a plate-like morphology is often obtained because of the predominance of OH − ions in the aluminate solution [24]. Herein, we present a simple, economical, and environmentally friendly route to precipitate boehmite with a specific morphology in a heterogeneous system.…”

Synthesis and Characterization of Boehmites Obtained from Gibbsite in Presence of Different Environments

“…Platelets, leaves and all kind of lamellar materials can be labeled as 2D materials 3,6,[16][17][18][19][20][21] . 3D materials comprise crystals with near cubic or spherical morphologies [22][23] , as well as three-dimensional assemblies of 1D or 2D crystals which receive several names as "urchin-like", "canteloup-like", "flower-like", "rosette-like", "hollow microspheres" and "three-quarte-sphere-like" structures [24][25][26][27][28][29][30][31][32] . Boehmite can be prepared by a solid state thermal transformation of gibbsite 2,[33][34][35][36][37][38][39] .…”

Performance Comparison of Steam-Based and Chromate Conversion Coatings on Aluminum Alloy 6060

“…The assignment of the peaks in each FT-IR spectra was performed using the existing literature[35][36][37][38][39] .The comparison of the potentiodynamic polarization curves of the conversion coatings showed a distinct behaviour related to the microstructural changes of AA6060 caused by chromate, chromatephosphate and steam surface treatments. It is reported in the literature 40 that presence of Fe containing intermetallic particles increase the cathodic activity of the surface and they act as preferential sites for pit initiation in the aluminium alloy matrix.…”