Cu nanostructures with different shapes were synthesized via a simple reduction approach from CuO nanoleaves at room temperature. The purity and morphology of samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements. By changing the dosage of reducing agent, Cu flowers and Cu octahedral cages were obtained successfully. The growth mechanism of morphology evolvement to different shaped Cu nanostructures is discussed. Thermo-gravimetric and differential thermal analysis (TG–DTA) results illuminated that Cu flowers sample has relatively higher activity to oxygen in air atmosphere compared to Cu octahedral cages. A well-defined, stable and fast amperometric response of glucose was observed when the Cu nanostructures were constructed as non-enzymatic glucose sensors. The Cu flowers modified electrode has higher sensitivity than Cu octahedral cages modified one.Graphical abstractCu flowers and Cu octahedral cages were synthesized by changing the dosage of reducing agent from CuO nanoleaves at room temperature. Cu flowers were obtained from the aggregated growth of Cu particles, while Cu octahedral cages were obtained by morphology heredity from the intermediate Cu2O. Cu flowers have relatively higher activity compared to Cu octahedral cages.Highlights► Cu flowers and octahedral cages were prepared by reducing CuO nanoleaves. ► Cu flowers have relatively higher activity compared to Cu octahedral cages. ► The Cu-constructed non-enzymatic sensor had good responses to glucose.

An aqueous reduction method was successfully used to prepare Bi nanoparticles at 90 °C with bismuth nitrate pentahydrate [Bi(NO3)3·5H2O] and sodium-hypophosphite (NaH2PO2·H2O) as reactants. The diameters of Bi nanoparticles were controlled in the range of 10–50 nm under varied experimental parameters. And Bi nanobelts can also be constructed through self-assembly of Bi nanoparticles, which had typical lengths of up to 10 μm and widths of up to 100 nm. Tartaric acid (TA, H2C4H4O6) and NaOH are key factors in our preparation. These Bi nanostructures are expected to find potential applications in a variety of areas due to their optical characteristics. Various techniques such as X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) were used to characterize the obtained nanostructures.Graphical abstractDifferent Bi nanostructures (nanoparticles and nanobelts) have been prepared by controlling experimental parameters. The optical absorption spectra of the shape-controlled Bi nanostructures show distinguished absorptions in the range of 200–1100 nm.Highlights► Bi nanostructures have been mildly synthesized via an aqueous reduction method. ► Tartaric acid introduction is necessary for the reducing process in basic condition. ► The quantity of NaOH has a key role for the shape evolution of Bi nanostructures. ► The optical properties changed with varied morphologies of Bi nanostructures.

This work focused on a synthetic method to produce flower-like nickel nanostructures under the induction of magnetic field. Flower-like nickel nanostructures were obtained by using nontoxic reactants, nontoxic solvents, and low reaction temperature. It was improved, comparing to other methods previously described. The XRD patterns showed an fcc-like structure and the thermal analysis showed the purity of flower-like nickel nanostructures. Flower-like structure was assigned by high-resolution scanning electron microscopy (HRSEM). The magnetic field induced the construction of nickel nanopowders. We also found the resultant nickel nanostructures as catalyst promoted the combustion of ammonium perchlorate.

In this work, we report a mild chemical procedure to synthesize rice ear-like cobalt microstructures using hydrazine hydrate as the reductive agent. The as-obtained products were characterized by X-ray diffraction, scanning electron microscopy, and vibrating sample magnetometry. The results show that the samples are hexagonal-close-packed (hcp) Co dendritic structures composed of a pronounced trunk and multiple ears. The length of the main trunk is tens of micrometers, and that of each ear is 3–5 μm with a width of about 1 μm. It was found that the chain length of surfactant PEG as directing agent drastically influenced the morphologies of the produced cobalt crystals. The morphologies of samples can be manipulated from cauliflower to flower and then to rice ear-like structures only by choosing PEG of different molecular weight as surfactant. These microstructures exhibited a ferromagnetic behavior at 300 K and might have potential applications in microdevices and other related magnetic devices.

We report here a simple approach to the synthesis of Cu2O/TiO2 core-shell nanocomposites with uniform octahedral structure in solution phase. First, fresh synthesized Cu2O octahedra were used as precursor, and butyl titanate (Ti(OBu)4) diluted by ethanol was preliminary hydrolyzed by the water adsorbed on the surface of Cu2O, so a very thin TiO2 condensed on the Cu2O surfaces. Then, when a mixture of water and ethanol was dropped into the reaction system, the Ti(OBu)4 would further hydrolyze and condense around the Cu2O to form TiO2, so octahedral Cu2O/TiO2 core-shell composites with uniform and compact TiO2 shells were obtained. This method is suitable for the formation of uniform integrated TiO2 shells and their thickness can be controlled by adjusting the ratio of water/ethanol (W/E). According to the surface photovoltage spectroscopy of the Cu2O/TiO2 composites, we think the material would have a potential application in photocatalysis and photoelectric transition.

Cobalt microspheres constructed by the assembly of nanoplatelets have been synthesized by a wet chemical reductive procedure at room temperature with the help of glycerin and citric acid and without additional surfactants. The size of the microspheres is about 2–5 μm and that of the nanoplatelets assembled the microspheres is tens of nanometers in thickness. In this synthetic system, cobalt acetate was employed as Co source, sodium hydroxide was used to manipulate the pH value of the reaction system, and hydrazine hydrate was used as a reducing agent. A series of experiments were performed with different amounts of glycerin, from 0.5 mL to 4 mL, the results reveal that the formation of cobalt microspheres is assisted by glycerin. The shape, structure, and magnetic properties of the final products were investigated by XRD, SEM and VSM. This kind of Co nanostructures shows a ferromagnetic behavior at room temperature with enhanced coercivity, and has potential uses in magnetic recording devices and other related nanodevices. A possible mechanism for the formation of microspheres is proposed.