Surfactant-Assisted Hydrothermal Synthesis, Physical Characterization, and Photoluminescence of PbWO₄

Abstract

Large-scale selective synthesis of uniform microcrystals lead tungstate (PbWO 4 ) with controlled morphologies has been achieved via a facile surfactant-assisted hydrothermal process. The formation of PbWO 4 crystal is strongly dependent on its reaction parameters. The variation of different types of surfactants (such as P123, cetyltrimethyl ammonium bromide (CTAB), poly (vinyl pyrrolidone) (PVP), and dodecyl benzene sulfonic acid sodium salt (SDBS), respectively), reaction temperature, and reaction time are found to play a crucial role in controlling the particle size and morphology of the products. The growth process has been investigated by carefully following time-dependent experiments, and the oriented attachment process has been proposed for the possible formation mechanism. The optical properties, such as UV-vis spectra and PL spectra of PbWO 4 crystals, were studied and the room-temperature photoluminescence of PbWO 4 samples with different morphologies was investigated.

Hydrothermal synthesis and electronic properties of FeWO4 and CoWO4 nanostructures

“…The tungstates continue attracting considerable attention because they are found to be a fascinating family of materials possessing various technological applications such as microwave, scintillation, optical modulation, magnetic and writing-reading-creasing devices, humidity sensors, optical fibers and photoluminescence materials [3,4]. Therefore, many tungstates such as MWO 4 (M = Mn, Fe, Co, Ni and Cu) [5], MnWO 4 [6,7,8], FeWO 4 [1,3,7], CoWO 4 [2,9], NiWO 4 [7,10,11], CuWO 4 [12,13], ZnWO 4 [7,11,14] and CdWO 4 [15] with a wolframite-type structure as well as CaWO 4 [7,16], AWO 4 (A = Ca, Sr) [17], SrWO 4 [7,18,19], SnWO 4 [20,21], BaWO 4 [7,22,23] and PbWO 4 [4,[24][25][26][27] with a scheelite-type structure have been synthesized employing various novel methods, which allow to obtain well-defined and high-pure materials, mainly nanosize tungstates.…”

Surfactant‐assisted synthesis of novel star‐like PbWO4 hierarchical architectures

“…With continuous reaction, assembled nanoparticles with relatively large sizes form the crystal nucleus. Small nanoparticles dissolve and recrystallize at the site of the large nanoparticles, since smaller particles have significantly higher surface free energies than larger ones [11,19]. At the same time, the growth of some crystal planes becomes restricted to the selective binding of SDBS anions, resulting in the anisotropic growth of PbWO 4 nanocrystals.…”

“…Tungstate crystals belong to the so-called self-activated scintillator family, and their intrinsic luminescence is caused by the radiative annihilation of self-trapped excitons localized in regular WO 4 or WO 6 units of sheelite or wolframite crystals, respectively [7][8][9]. An important scintillating crystal, lead tungstate (PbWO 4 ) features high density (8.3 g/cm 3 ), fast decay time (less than 10 ns for the most part of light output), high irradiation damage resistance, and interesting excitonic luminescence, thermoluminescence, and stimulated Raman scattering behavior [10,11]. Generally, PbWO 4 single crystals are synthesized using expensive methods, such as solid-state reactions [12,13], flux methods for crystal growth [14], and the Czochralski [15] and Bridgman methods [16].…”

“…Moreover, these methods are expensive; they require expensive equipment and high synthesis temperatures. To minimize these problems, soft chemical methods, such as sol-gel [17], sonochemical routes [18], microemulsion [19], and hydrothermal [11] In this paper, we report a facile surfactant-assisted technology for the preparation of star-like PbWO 4 hierarchical architectures that are self-assembled from tiny PbWO 4 nanoellipsoids under mild conditions and in the presence of a mixed solvent of ethylene glycol and water. On the basis of the results obtained, a possible formation mechanism for such hierarchical architectures is suggested.…”

Modeling of the size effect on the hysteresis characteristics of core-shell nanoparticles Co-Au

“…One of such materials are magnetic core-shell nanoparticles with unique properties, which allows their use in various fields [1][2][3][4][5][6][7]. In this paper we will present modeling of the size effect on the coercive force, residual saturation magnetization, saturation magnetization of the Co-Au core-shell nanoparticles, which due to their unique properties are widely used in biomedicine.…”