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Diverse multipod-shaped CdSe nanocrystals with a high yield and good crystallinity were synthesized via microwave irradiation route, which only needed a period of 10 min. Cd(NO 3 ) 2 and selenium powders were used as raw materials in the preparation, which were safer and greener relative to the commonly used trioctylphosphine-based precursors for synthesizing CdSe tetrapods. By selectively introducing organic additives into the system, the morphology of CdSe nanocrystals could vary from tetrapods to hexapods, octapods, and more complex multipods. The possible growth mechanisms of the multipods were discussed based on the investigations on the structure and shape of intermediates. The present microwave irradiation route should provide an alternative to the rapid and controllable growth of other important selenides with distinct morphologies.

This manuscript describes the low-temperature, solution-based doping of Mn2+ ions into colloidal ZnO nanorods, and the yield of the products is in a gram scale. The structures and chemical compositions of the products were characterized by XRD, XPS, EDS, and FT-IR spectroscopy. The results demonstrate that Mn2+ ions were successfully incorporated into the lattice position of Zn2+ ions in ZnO. The concentration of Mn2+ ions (in molar %) in the products can be controlled in the range of 1.25∼5%. The surfaces of Mn-doped ZnO nanocrystals have very rich hydroxyl groups, which enhance their solubility in many polar and nonpolar solvents. TEM and FESEM were used to characterize the morphology of ZnO and Mn-doped ZnO nanocrystals, and they revealed that both the undoped and doped ZnO nanocrystals are composed of uniform nanorods with a diameter of 8 nm and a length of 95 nm. The doping of Mn2+ ions has significant influences on the optical properties of ZnO nanorods. UV−vis absorption spectroscopy measurements r...

This manuscript describes a self-organization method for the large-scale production of porous ZnS/ZnO composite microspheres and their application as supports of CdTe quantum dots. Through the reaction of Zn 2+ and urea and thioacetamide at 85 °C for 10 min, nanoparticles of cubic ZnS and amorphous ZnO were formed and they present a strong tendency to organize into regular microspheres. The formation of nanopores within the microspheres is related to Ostwald ripening: some small nanoparticles within the microspheres were merged by the larger ones, and as a result, numerous nanopores were generated. Furthermore, when a solvothermal ripening is applied for the porous microspheres, the components within them can be transformed into hexagonal ZnS and ZnO. CdTe quantum dots were introduced into the nanopores to achieve luminescent microspheres through in situ nucleation and growth. And it is expected that, besides semiconducting quantum dots, other functional units, such as magnetic and catalytically activated nanoparticles, can also be introduced into them.

This manuscript describes a simple, environmentally friendly strategy for the rapid and large-scale growth of ultralong nanowires and nanoribbons of wurtzite CdTe. The nanowires and nanoribbons were prepared through the direct hydrothermal treatment of CdTe nanoparticles precoated on ⟨100⟩ Czochralski silicon, which did not involve complicated reactions. The well-crystalline nanowires and nanoribbons were grown along the [102] direction and were up to 100 μm long. The growth of the nanowires and nanoribbons was dominated by the mechanism of oriented attachment, which was clarified through the tracing of the temporal evolution of CdTe nanoparticles coated on the silicon substrate in the process of hydrothermal treatment. Furthermore, the proposed strategy was also effective in the preparation of anisotropic nanostructures of other II−IV group compounds (e.g., ZnO and CdSe).

Morphology-controlled growth of nanomaterials is an important topic in nanosciences because it is the prerequisite of the applications of nanomaterials. In this work, we reported the microwave-enhanced rapid and green synthesis of Sb 2 Se 3 nanorods with a flat cross section through the reaction between selenium powders and sodium antimony tartrate. Microwave irradiation greatly shortened the reaction time, which made the cycle to be as short as 30 min. The intrinsic mechanism for the formation of nanorods with a flat cross section is related to the direction of the unique layer-structured structure of orthorhombic Sb 2 Se 3 .

This work describes the synthesis and magnetic–optical properties of Fe 3 O 4 nanowires decorated by CdTe quantum dots. The composite nanowires with a length of 1 μm and an average diameter of 23±3 nm were prepared in a high yield through the preferential growth of Fe 3 O 4 on CdTe quantum dots using ethylenediamine as template. Their growth mechanism was discussed based on the results of control experiments. Studies on the optical and magnetic properties of the composite nanowires reveal that they assume not only yellow-green emission feature but also room temperature ferromagnetism.

We proposed a general and highly efficient wet strategy for the fabrication of ordered anisotropic nanostructures on the solid substrate. The method involves the pre-deposition of colloidal precursors onto the surface of the silicon substrate and the subsequent hydrothermal crystallization. In the process of crystallization, the colloidal precursors can develop into distinct shapes. The use of the substrate can promote the nucleation and the occurrence of anisotropic growth and induces the products to grow into ordered structures. With this method, regular ZnO nanoellipsoids, SnO 2 and Cd(OH) 2 nanorod clusters, and Bi 2 S 3 nanowires were prepared readily. The growth processes of the four regular nanostructures were studied through the investigations of the morphology of precursors and intermediates.

High-quality Cu3Se2 nanoplates were synthesized in a large scale through microwave-enhanced reaction between selenium and copper(I) oleate. The nanoplates are approximately round with thickness of 17 nm and the diameter in the range of 700∼1000 nm. The distinct shape of the nanoplates provides an ideal site for combining functional units, and as an example, carboxyl-terminated CdTe quantum dots were adsorbed onto Cu3Se2 nanoplates to form Cu3Se2−CdTe nanocluster by the chemical linkage of carboxyl to Cu. The fabricated nanoclusters exhibit an enhanced photovoltaic property (i.e., large photocurrent and short response time). Furthermore, this work provides a rational method to the design and fabrication of quantum dots decorated semiconductor nanocomposites.

In this manuscript we have demonstrated a template-free route to the preparation of hollow In 2 S 3 nanospheres by solvothermally treating solid In 2 S 3 spheres comprised of small particles at 180 °C for 24 h. This method is simple but highly efficient, which can transform the solid precursors into hollow nanostructures in an extremely high yield. Investigations into the intermediates reveal that the formation of hollow spheres is through the mergence of the smaller particles within the solid spheres by the relatively large ones in the ripening process (i.e., Ostwald ripening). The well crystalline hollow nanospheres have the diameters of 40–70 nm and an average wall thickness of 7 nm. Due to the closeness of the size of hollow nanospheres to the Bohr radius (33.8 nm) of the excition in In 2 S 3 , an obvious quantum size confinement and morphology-dependent property are observed. Hollow In 2 S 3 nanospheres show an intense absorption between 318 and 512 nm, which is blue-shifted to shorter wavelengths relative to that of bulk In 2 S 3 . Hollow In 2 S 3 nanospheres also exhibit a strong photoluminescence. The green band centered 518 nm is due to the band-band transitions and the orange emission centered at 624 nm originates from the indium interstitial defect. These hollow In 2 S 3 nanospheres could be used as a distinctive multicolored phosphor and material for producing photoelectrochemical devices.