Hydrothermal synthesis of boehmite (γ-AlOOH) nanoplatelets and nanowires: pH-controlled morphologies

Under hydrothermal conditions, we have prepared boehmite (γ-AlOOH) with two distinct nanostructures—2D nanoplatelets and 1D nanowires (or nanowire bundles)—simply by manipulating the acidity of the reaction solution without adding any templates or seeds. The 2D nanoplatelets with a thickness of ~20 nm and the 1D nanowires with a high aspect ratio of 400-700 were synthesized at pH = ~10 and ~5, respectively. One possible mechanism for the formation of these nanostructures was proposed on the basis of acidity conditions. The PL spectra of these nanostructures display different emission bands, and this difference might be due to their distinct sizes and morphologies.