Solvothermal synthesis and growth mechanism of ultrathin Sb2Te3 hexagonal nanoplates with thermoelectric transport properties

Abstract

Uniform single-crystalline hexagonal-shaped Sb 2 Te 3 nanoplates with a thickness of 30-40 nm have been successfully synthesized by a glucose-assisted solvothermal process in the mixed solvents of ethanediamine and water. It is found that the reaction time, concentration of glucose, reaction temperature and the volume ratio of ethanediamine to water play important roles in the formation of the uniform Sb 2 Te 3 nanoplates. Based on the experimental results, the possible reaction process and formation mechanism of these hexagonal nanoplates is proposed. Different from previous reports, the growth process of such Sb 2 Te 3 nanoplates can be reasonably explained by a self-assembly process and an Ostwald ripening mechanism. The thermoelectric transport properties are investigated by measuring the electrical conductivity and the Seebeck coefficient in the temperature range of 300-600 K. The samples show much more enhanced Seebeck coefficients than that of bulk Sb 2 Te 3 . Meanwhile, the size of the sample has much impact on both the electrical conductivity and the Seebeck coefficient.

A Facile Route to Flowerlike Bi2S3 Constructed by Polycrystalline Nanoplates with Enhanced Electrochemical Properties

“…As reported in the literature, the temperature has much effect on the reaction rate, which results in the different sizes and morphologies of the final products. [39][40][41] In our experiment, a similar phenomenon can be observed. Lower reaction temperature leads to the formation of Bi 2 S 3 microspheres.…”

“…Such an aggregation process and anisotropic growth mechanism can be observed in the formation of CaCO 3 mesocrystals and Sb 2 Te 3 nanoplates. [38,39] Figure 4 shows the FESEM images and the XRD pattern of the final product prepared at different reaction temperatures. The XRD pattern of the sample synthesized at 100°C is shown in Figure 4a.…”

Twin-induced one-dimensional homojunctions yield high quantum efficiency for solar hydrogen generation

“…It is also noteworthy that EN has played a crucial role for in the formation our 1D-nanorod structure. In fact, similar role of EN has also been found for the formation of many anisotropic structures on various materials, such as nanowire, nanorod, and nanosheet/plate and so on [41][42][43][44][45] . It was proposed that atoms on coherent {111} twin plane possessed high coordination number and had relatively low formation energy even comparable to the normal {111} facets 27,[46][47][48] .…”

Hydrothermal method for the synthesis of Sb2Te3, and Bi0.5Sb1.5Te3 nanoplates and their thermoelectric properties

“…The obtained Seebeck coefficient for Sb 2 Te 3 nanobulk at room temperature was 145 μV/K, which is significantly higher than undoped Sb 2 Te 3 single crystals (83 μV/K at room temperature), and Sb 2 Te 3 nanostructures produced by surfactant‐assisted reflux method (103 μV/K at room temperature) . The maximum S value reached 181 μV/K at 400 K, which is larger than that of an Sb 2 Te 3 hexagonal nanoplates by Solvothermal process (161.7 μV/K at 400 K) . The shifting of peak Seebeck coefficient to higher temperature for Sb 2 Te 3 nanobulk samples can be attributed to preferential scattering of minority carriers by nanostructured grain boundaries .…”