The Single Molecular Precursor Hydrothermal Solvothermal Synthesis Of Chalcogenide Nanomaterials

In this thesis, a series of chalcogenides were synthesized by using complex as precursors via hydrothemal route. By varying reaction condition and choosing the suitable precursors, the nanocrystal with different morphology were obtained. The main point can be summarized as follows:1. Ternary branch-shaped ZnxCd1-xS nanoparticles have been prepared firstly using ZnCd(SCN)4 as a single-source molecular precursor via the hydrothermal route. Transmission electron microscopy and scanning electron microscopy images indicate that the particles are branch-shaped, and X-ray diffraction patterns show the material consisted the hexagonal phases ZnS and CdS. Zn2+ is found to play a crucial role in the formation of branch-shaped ZnxCd1-xS. The nanoparticles exhibit emission band peak at 434 nm.2. A fine solvothermal method was performed to investigate reaction process, and an unexpected CdS xen nanobelts was obtained. The transmission electron microscopy image of the sample shows that the dominant morphology is belt-like appearance with widths in the range of 50-150 nm, lengths in the range of 2-6 um, and typical width-to-thickness ratios of 4 ~ 7. Interestingly, the nanobelts are fragile and unstable under electron beam bombardment, and turn uneven appearance owing to the presence of some bubble. This method might be expended to synthesize other nanomaterial.3. A nonaqueous synthesis route to hexapod PbS nanocrystals has been presented. Surfactant, namely oleic acid, plays a key role in the synthesis of hexapod PbS. Although the exact reason is unknown, it is still noteworthy that the configuration of the symmetry group Oh in PbS nanocrystals is unprecedented.4. Bi2S3 and Sb2S3 nanorods were synthesized from single-source precursors M(S2CNEt2)3 (M = Bi, Sb) via hydrothermal treatment. The X-ray powder diffraction patterns show that both of the products belong to the orthorhombic phase, and are phase-pure. Transmission Electron Microscopic studies reveal the rod-like appearanceof either Bi2S3 or SbiSs with diameters in the range of 50-400 nm and lengths in the range of 1-7 um. The experimental results show the nanorods can be prepared in protic solvent under experimental conditions (at 115-140 C for 10 h). The possible mechanism is discussed.