Homogeneous Ag nanosheet-assembled film was successfully fabricated by using Cu plate through a simple modified solution method, where weak reductive Cu2O layer and complexing agent citrate ions were both introduced into the reaction system to control the reaction process. Meanwhile, citrate ions were used as morphology-controlled reagent to lead Ag units to grow in the form of nanosheet. The growth process exhibited that Ag nanosheet-assembled film formed slowly with reaction proceeding. Additionally, the pack density of nanosheets in the final product was found to be adjusted by the concentrations of Ag(+) ions in precursor solution. Using Rhodamine 6G (R6G) as probing molecules, the surface-enhanced Raman scattering (SERS) experiments showed that the Ag film assembled by nanosheets with high pack density exhibited excellent detecting performance, which could be used as effective SERS substrate for ultrasensitive detecting. Besides, a novel quintuplet SERS substrate could be synthesized in one batch by our method, which showed good reproducibility and a linear dependence between analyte concentrations and intensities, revealing the advantage of this method for easily scale-up production.

We present successful fabrication of single n-ZnO/p-AlGaN heterojunction nanowires with excellent optoelectronic properties. Because of the formation of high-quality interfacial structure, heterojunction nanowire showed a diodelike rectification behavior and an electroluminescence (EL) ultraviolet (UV) emission centered at 394 nm from a single nanowire was observed when the injection current is 4 μA due to high exciton efficiency in the interfacial layer between ZnO and AlGaN. With the increase of the applied current, the EL peak at 5 μA becomes weaker revealing an optimal injection current of less than 5 μA. These results are expected to open up new application possibilities in nanoscale UV light-emitting devices based on single ZnO heterostructure.

The Mn3O4 nanostructures having low temperature Curie point (45 K) disqualify them for most practical applications. In this work, single-crystalline Cr-doped Mn3O4 nanowires with ferromagnetic Curie point at room temperature (305 K) have been investigated. Our experimental results show an increase in effective magnetic moment per gram as Cr3+ replaces Mn3+ and oxygen vacancies, which result in a transition from paramagnetic (Mn3O4) to ferromagnetic. The doped Cr3+ and oxygen vacancies reveal the remarkable ferromagnetic in Mn3−xCrxO4 nanowires may be ascribed to bound magnetic polarons model. Our experimental results suggest these obtained nanowires are promising nanoscale building blocks in spintronic devices.

Single crystalline one-dimensional (1D) nanostructures of silver telluride (Ag2Te) with well-controlled shapes and sizes were synthesized via the hydrothermal reduction of sodium tellurite (Na2TeO3) in a mixed solution. The morphological evolution of various 1D nanostructures was mainly determined by properly controlling the nucleation and growth process of Ag2Te in different reaction times. Based on the transmission electron microscopy and scanning electron microscopy studies, the formation mechanism for these 1D nanostructures was rationally interpreted. In addition, the current–voltage (I-V) characteristics as a function of magnetic field of the highly single crystal Ag2Te nanowires were systematically measured. From the investigation of I-V characteristics, we have observed a rapid change of the current in low magnetic field, which can be used as the magnetic field sensor. The magneto-resistance behavior of the Ag2Te nanowires with monoclinic structure was also investigated. Comparing to the bulk and thin film materials, we found that there is generally a larger change in R (T) as the sample size is reduced, which indicates that the size of the sample has a certain impact on magneto-transport properties. Simultaneously, some possible reasons resulting in the observed large positive magneto-resistance behavior are discussed.