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Flexible, paper-based graphene and graphene oxides are now emerging as a new class of materials with a variety of applications in electrochemical devices, novel composites, antibacterial agents, separation membranes, and so on. But the tight layer and the poor permeability limit their applications in the fields requiring permeable layers and tunable layer spacing. We demonstrate that the temperature-dependent decomposition reaction of ammonium nitrate can be utilized to modulate the layer spacing of graphene oxide paper and modify its permeability. Unlike the commonly used intercalation method, our strategy enables the layer spacing of the paper to be expanded over large range (123%–20 000%) and avoids the occupation of layer room by guest molecules. Dependent on the expansion amplitude, the papers exhibit a variety of interesting applications, including the highly efficient exclusion of small organic molecules, the separation of ultrathin nanoparticles, and the loading of polar and nonpolar guest molecul...

A large-area, nest-like ZnO nanowires (NWs) array was prepared through the oxidation reaction between zinc foil and (NH4)2S2O8 at 150 °C for 18 h. CdTe quantum dots (QDs) were linked chemically to the array to form CdTe/ZnO heterostructures based on the good affinity of carboxyl to zinc ions. The molar content of CdTe in the heterostructures can be controlled at the level of 1.2%, 5.1%, and 11.4%, which depends on the soaking time of ZnO array in CdTe solution. The measurements of the optical properties of the as-prepared CdTe/ZnO heterostructures reveal that they can harvest incident lights more efficiently than can unmodified ZnO NWs arrays, whose reflectance was decreased about 20%. The good light-trapping effect and the attachment of CdTe QDs significantly improve the photovoltaic properties of the heterostructure and result in a good rectifying behavior. The photoanode based on the heterostructures has open-circuit voltages of 0.5−0.6 V and a short-circuit current of 0.3 mA/cm2.

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...

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.