Effect of synthesis conditions on luminescence properties of PbWO4 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.