Gelatin-mediated hydrothermal synthesis of apple-like LaCO3OH hierarchical nanostructures and tunable white-light emission

Abstract

A fabrication of uniform apple-like LaCO₃OH hierarchical nanostructures was achieved by a facile hydrothermal route using gelatin as the reactant and structure-directing agent. The hierarchical nanostructures with diameters of 2–5 μm are built from numerous nanoplatelets with thicknesses of 10–20 nm and lengths of 30–80 nm. Influential factors such as reaction time, reaction temperature, dosage of gelatin and potassium hydroxide were systematically investigated. A dipole-field-driven process was suggested for the formation of the apple-like LaCO₃OH hierarchical nanostructures. Strong emission centring at 432 nm was realized in the apple-like LaCO₃OH hierarchical nanostructures on excitation with 365 nm ultraviolet light. It turns out that it is easy to tune the luminescent characteristics of the LaCO₃OH hierarchical nanostructures in a wide spectral range by simply varying excitation lines or doping concentration of Eu³⁺ and Tb³⁺. Particularly, white light emission can be obtained in the Eu³⁺ and Tb³⁺ codoped LaCO₃OH hierarchical nanostructures on excitation in a wide ultraviolet band.