Growth mechanism and photoluminescence properties of controlled PbWO4 micro- and mesocrystals obtained by the surfactant-assisted solvothermal method

In this paper, we report on the ortho-hexaclaval and size-controlled spherical PbWO 4 micro- and mesocrystals synthesized by the surfactant-assisted solvothermal method with cationic surfactant cetyltrimethylammonium bromide (CTAB), deionized water or ethylene glycol solvents. The resulting hierarchical PbWO 4 crystals were characterized by X-ray diffraction, field emission scanning electron microscopy, high-resolution transmission electron microscopy and selected area electron diffraction. Experimental results indicated that CTAB played a critical role in the formation of specific structures. Finally, the optical properties were investigated at room temperature by means of ultraviolet-visible diffuse reflectance and photoluminescence measurements. High-magnification FE-SEM images of the final products: (a) ortho-hexaclaval, (b) 2 μm spherical, (c) 3 μm spherical, and (d) 4 μm spherical PbWO 4 crystals, respectively.