Effect of synthesis conditions on luminescence properties of PbWO ₄ nanospheres and nanoflakes

Lead tungstate (PbWO₄) nanospheres and nanoflakes have been prepared by template directed synthesis using a biotemplate based on a new egg shell. The product was characterised by X-ray diffraction, scanning electron microscopy and luminescence spectrophotometer. The product morphology could be transformed from nanospheres to nanoflakes via a simple change of solvent. A green emission peak at 480 nm was observed for the flake PbWO₄, whereas the emission peak was blue for the PbWO₄ nanospheres. The effect of solvent type on the morphology and properties of the synthesised PbWO₄ was investigated and a possible formation mechanism for nanospheres or sheets is proposed. The PbWO₄ nanocrystals have potential optical applications.