Xingcai Wu

Crystalline gallium oxide nanowires: intensive blue light emitters

Abstract Gallium oxide nanowires (GaONWs; diameter, ca. 60 nm; length, hundreds of micrometers) have been synthesized by a carbothermal reduction reaction. The nanowires have been confirmed as crystalline β -Ga 2 O 3 by powder X-ray diffraction and selected area electronic diffraction. The GaONWs can emit stable and high brightness blue light at 446 nm (2.78 eV) under excitation at 378 nm (3.28 eV), which may have potential applications in one-dimensional optoelectronic nanodevices.

Preparation and photoluminescence properties of amorphous silica nanowires

Abstract Bulk-quantity amorphous silica nanowires (SiONWs) have been synthesized by carbothermal reduction reaction between silicon dioxide and active carbons. Transmission electron microscopy (TEM) image shows the formation of the nanowires at a diameter of 60–110 nm and a length up to hundreds micrometers. Besides most smooth-surface polyp-shaped nanowires, two other forms of nanowires, named amoeba-shaped and frog-egg-shaped nanowires, have also been observed. The nanowires can emit stable and high brightness blue light at 435 nm (2.85 eV) under excitation at 260 nm (4.77 eV). The formation of the nanowires into different shapes may be explained by the vapor–liquid–solid (VLS) mechanism.

Fabrication and photoluminescence characteristics of single crystalline In2O3 nanowires

Abstract Single crystalline In2O3 nanowires (InONWs) have been synthesized by carbothermal reduction reaction between indium oxide and active carbons at 980 °C in flowing nitrogen atmosphere. Transmission electron microscopy (TEM) image shows the formation of the nanowires at a diameter of about 20–200 nm and a length of up to hundreds of micrometers. The nanowires can emit stable and high brightness blue light at 416 and 435 nm under excitation at 260 nm. The growth process of the nanowires may be explained by vapor–solid mechanism.

Electrical Transport and High‐Performance Photoconductivity in Individual ZrS2 Nanobelts

Individual ZrS(2)-nanobelt field-effect transistors were fabricated using a photolithography process. Temperature-dependent electrical transport revealed different electrical conductivity mechanism at different working temperature regions. ZrS(2)-nanobelt photodetectors demonstrated a high-performance visible-light photoconductivity.

Preparation and photoluminescence properties of crystalline GeO2 nanowires

Abstract Bulk-quantity GeO 2 nanowires (GeONWs) have been synthesized by carbothermal reduction reaction between germanium dioxide and active carbons. Transmission electron microscopy (TEM) image shows the formation of the nanowires at a diameter about 50–120 nm and a length up to hundreds of micrometers. The nanowires can emit stable and high brightness blue light at 485 nm (2.56 eV) under excitation at 221 nm (5.61 eV). The intensity of the emission is one order of magnitude higher than that of GeO 2 powders. The photoluminescence (PL) may originate from radiative recombination between an electron on V O × and a hole on ( V Ge , V O ) × in the GeONWs. The nanowires may have potential applications in one-dimensional optoelectronic nanodevices.

Flexible photodetector from ultraviolet to near infrared based on a SnS2 nanosheet microsphere film

A new flexible ultraviolet (UV) to near infrared (NIR) photodetector based on a SnS2 nanosheet self-assembled microsphere film has been fabricated onto a transparent polypropylene (PP) film using double-side adhesive tape, and its light-induced electric properties were investigated in detail. The detector demonstrates a remarkable photoresponse from 300 to 830 nm, a remarkable photocurrent depending on the optical power and light wavelength, as well as an excellent photoswitch effect and stability. In addition, another new rigid photodetector based on the same SnS2 microsphere film has been fabricated on a SiO2/Si substrate, showing similar photosensitive properties. It suggests that SnS2 nanosheet microspheres are potential candidates for high-performance nanoscale optoelectronic devices, and the SnS2-microsphere-based photodetector can be applied as a photodetector in the range of UV to NIR light because of its low cost and nontoxicity.

Green preparation and catalytic application of Pd nanoparticles

A green strategy for the facile preparation and effective stabilization of Pd nanoparticles has been developed by using D-glucose as the reducing and stabilizing agents. The UV/vis absorption spectroscopy, transmission electron microscopy (TEM), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and zeta potential measurements were used to characterize the as-prepared Pd nanoparticles. It was found that the D-glucose concentration and pH value had an important effect on the size distribution and stability of the nanoparticles. Further, the Pd nanoparticles exhibited good catalytic properties in the degradation of azo dyes.

Aqueous synthesis of color-tunable CuInS2/ZnS nanocrystals for the detection of human interleukin 6.

In this Article, we present a facile microwave-assisted synthesis route for the preparation of water-soluble and high-quality CuInS2/ZnS nanocrystals (NCs) with glutathione as the stabilizer. The as-prepared CuInS2/ZnS NCs exhibited small particle sizes (~3.3 nm), long photoluminescence lifetimes, and color-tunable properties ranging from the visible to the near-infrared by varying the initial ratio of Cu/In in the precursors. The low-toxicity, highly luminescent and biocompatible CuInS2/ZnS NCs were applied to cell imaging, showing that they could be used as promising fluorescent probes. Furthermore, the CuInS2/ZnS NCs were used as the signal labels for a fluoroimmunoassay of the biomarker IL-6, showing their great potential for use as reliable point-of-care diagnostics for biomarkers of cancer and other diseases.

Synthesis and characterization of self-assembling (NH4)0.5V2O5 nanowires

Large-scale long (NH4)0.5V2O5 nanowires have been synthesized by rational hydrothermal treatment of ammonium metavanadate at 170 °C. Scanning electron microscope and transmission electron microscope analyses show that the nanowires have diameters of about 20–80 nm, and lengths up to 0.5 mm. Some self-assembled nanobelts are observed with a thickness of 18 nm and width of 100–200 nm. Electrical transport measurements shows that the nanowires are semiconductors with a conductivity of about 10−3 S cm−1 at room temperature. The conduction mechanism can be explained by small polaron hopping in transition metal oxides.

Flexible Visible-Light Photodetectors with Broad Photoresponse Based on ZrS3 Nanobelt Films

Two new flexible visible-light photodetectors based on ZrS3 nanobelts films are fabricated on a polypropylene (PP) film and printing paper, respectively, by an adhesive-tape transfer method, and their light-induced electric properties are investigated in detail. The devices demonstrate a remarkable response to 405 to 780 nm light, a photocurrent that depends on the optical power and light wavelength, and an excellent photoswitching effect and stability. This implies that ZrS3 nanobelts are prospective candidates for high-performance nanoscale optoelectronic devices that may be practically applied in photodetection of visible to near infrared light. The facile fabrication method is extendable to flexible nanodevices with different nanostructures.