Solvothermal Synthesis of V−VI Binary and Ternary Hexagonal Platelets: The Oriented Attachment Mechanism

Abstract

General synthesis of both binary and ternary V-VI based thermoelectric alloy hexagonal platelets was carried out for the first time in a unified system using a modified solvothermal method, which adopted convenient oxides as source materials and friendly ethylene glycol as both solvent and reducing agent. The structure and composition analysis reveal that the samples are pure phase with corresponding atomic ratios. Electron microscopy results indicate that the as-prepared products are uniform and highly crystallized. The formation process was studied in detail by observing time-dependent products, and it was found that the oriented attachment mechanism could be responsible for the growth of these hexagonal platelets, which exhibits intrinsic difference compared with the inferred seed-mediated growth mechanism in previous reports. The influence of pH value and polyvinyl pyrrolidone on the morphology of the products was investigated as well. This work may open up a new rationale on designing the solution synthesis of nanostructures for materials possessing similar intrinsic crystal symmetry.

Fabrication of Graphene/Bi2Se3/Graphene heterostructure without the surface oxidation of Bi2Se3

“…Layer-structured Bi 2 Se 3 materials may be applied for the future spintronics and quantum computing devices due to large ratio of surface-to-volume, thus it is urgent to synthesize high-quality Bi 2 Se 3 with defined sizes [2][3][4]. Various methods have been tried to fabricate Bi 2 Se 3 thin film, such as molecular beam epitaxial (MBE) [5,6], solvothermal synthesis [7], mechanical exfoliation [8], metalorganic chemical vapor deposition (MOCVD) [9] and chemical vapor deposition (CVD) [10][11][12][13]. Compared with other methods, CVD is an inexpensive and effective strategy to obtain Bi 2 Se 3 materials.…”

Formation of randomly distributed nano-tubes, -rods and -plates of n-type and p-type bismuth telluride via molecular legation

“…Recently, synthesis of bismuth telluride based thermoelectric nanomaterials in different morphology has attracted lot of interest [1][2][3][4][5][6][7][8][9][10][11][12]. This interest is driven by the performance enhancement of the thermoelectric nanomaterials in diverse morphology at nanoscale [4,13].…”

“…In addition, these processes have been applied mostly to binary bismuth telluride [2][3][4][5][6][7][8][9][10]. However, there are few reports on synthesis of ternary alloys [1,11,12], but these processes yielded platy structure. Of course, nanorod [8] and nanotube [13] morphology have also been obtained in binary bismuth telluride.…”

Two-dimensional nanoplates of Bi2Te3 and Bi2Se3 with reduced thermal stability

“…Therefore, the aspect ratio defined as the width/thickness can be close to 190, which appears to be the highest among the Bi 2 Te 3 nanostructures reported in previous literatures. [24][25][26] On the contrary, when PVP was not present in the reaction, it was verified that Bi 2 Te 3 grew into irregular particle shapes rather than in the platelets. As PVP concentration increased over 0.5 mmol, the effect saturated and further thinning effect was not observed.…”