Morphology-controllable synthesis and photoluminescence properties of t-LaVO 4 :Ln 3+ nanostructures on glass substrates

Tetragonal t-LaVO 4 :Ln 3+ (Ln 3+ = Eu 3+ , Dy 3+ , Sm 3+ ) microrod array and 3D hierarchical nanostructures with sheaf-like, flower-like, cauliflower-like, and spherical morphologies have been successfully synthesized on glass substrate through a simple hydrothermal process assisted by ethylenediaminetetraacetic acid disodium salt (Na 2 H 2 L). The morphologies of the products varied dramatically when Na 2 H 2 L/La 3+ molar ratio and reaction time were changed in system. A possible crystal growth mechanism is proposed for the self-assembly of nanorods into the observed microstructures based on detailed experiments. Due to an efficient energy transfer from VO 4 3− to the Ln 3+ dopants, the self-assembled t-LaVO 4 :Ln 3+ (Ln 3+ = Eu 3+ , Dy 3+ , Sm 3+ ) superstructures showed strong characteristic dominant emissions of the Eu 3+ , Dy 3+ , Sm 3+ ions at 616 nm ( 5 D 0 → 7 F 2 , strong red), 573 nm ( 4 F 9/2 → 6 H 13/2 , yellow), 603 nm ( 4 G 5/2 → 6 H 7/2 , orange-red) under ultraviolet excitation, respectively. This work not only gives insight into understanding the hierarchical growth behaviour of t-LaVO 4 :Ln 3+ nanoarchitectures in a solution-phase system, but also provides a potential route to building other superstructures assembled from one-dimensional nanoparticles.