A Microwave Route for the Synthesis of Nanoflakes and Dendrites-Type β-In₂S₃ and their Characterization

Abstract

In this article, a simple microwave route was applied for the synthesis of nanoflakes and dendrite-type beta-indium sulfide (In2S3) in high yield (> 97%), using a homogeneous mixture of indium(lll)chloride and thiourea in an ethylene glycol (EG)/polyethylene glycol (PEG400) solvent. The reaction was conducted in a simple domestic microwave oven (DMO). Powder X-ray diffraction (XRD), low resolution and high resolution transmission electron microscopy (LRTEM and HRTEM), selected area electron diffraction (SAED), and energy dispersive X-ray spectroscopy (EDS), were applied to investigate the crystallinity, structure, morphology, and composition of the In2S3 nano-materials. Both the as-synthesized and calcined In2S3 products were a body-centered tetragonal (bct) phase, observed by XRD and HRTEM. The length and width of the resulting nanoflakes were in the range of 70-600 nm and 4-10 nm, respectively. The optical band gap of the powder was determined by diffuse reflectance spectroscopy (DRS) and was found to be 2.44 eV. The electronic properties of the products were studied by measuring the optical absorption spectra using photoacoustic spectroscopy. The band gap calculated by this method was found to be 2.52 eV. A possible mechanism for the formation of nanoflakes/dendrites-type In2S3 was also discussed.

Microwave chemistry for inorganic nanomaterials synthesis

“…149 The group of Gedanken was particularly active in the field of metal chalcogenide preparation, including aqueous (e.g., II-VI binary chalcogenides such as CdSe, PbSe, and Cu 2Àx Se), 150 as well as nonaqueous systems. Especially the adaptation of the polyol route gave access to a large variety of binary chalcogenides such as PbTe, 151 PbSe, 151 CdSe, 152 SnS, 153 SnS 2 , 153 CdSe, 152 In 2 S 3 , 154 159 and Cd 1-x Zn x Se. 160 Another organic solvent suitable for the preparation of metal chalcogenides is formaldehyde.…”

Synthesis of In2S3microspheres using a template-free and surfactant-less hydrothermal process and their visible light photocatalysis

“…[9][10][11] Phase-controlled synthesis and stabilization of a particular In 2 S 3 phase at room temperature depend on the growth process (by impurity incorporation). 7 Various architectures of In 2 S 3 such as 3D flower-like structures, 12 hollow nanospheres, 13 nanosheets, 14 urchin-like nanostructures, 15 and nanoflake structures 16 have been prepared using microwave, 17 sonochemical, 18 hydrothermal and solvothermal methods. 14 These solution-based techniques are particularly attractive because of their low-temperature synthesis and potential for large-scale production.…”

In2S3 nanostructures: semi-batch synthesis and characterization and its photovoltaic applications

“…In 2 S 3 nanoparticles can also have medical applications as bioconjugates for cancer diagnosis [14,15]. So far, various morphologies and architectures In 2 S 3 nanostructures have been reported, such as nanoparticles [11,16,17], dendrites [18][19][20], dendritic patterns [18], hollow nanospheres [21], nanowires and micro-and nano-rods [22][23][24][25], films [26,27], nanosheets [28], bulk powder [11,13,27], 3D Flowerlike Structures [29], nano-flake structures [30], and urchin-like nanostructures [31]. Many efficient techniques were developed for preparing semiconductor micro and nano-size In 2 S 3 , mainly including microwave route [20], Sonochemical method [32], hydrothermal and solvothermal method [11,28], precipitation [16], solvent-reduction route [17], metalorganic chemical vapor deposition approach [23], oxidization-sulfidation growth route [18], thermal decomposition [33], a direct reaction of the elements in a quartz container at a high temperature [34], the laser-induced synthesis [35] and so on.…”