Improvement of the UV-Sensing Performance of Ga-Doped ZnO Nanostructures via a Wet Chemical Solution at Room Temperature

In this investigation, ultraviolet (UV) photodetectors (PDs) were fabricated from zinc oxide (ZnO) and Ga-doped ZnO nanostructures on a Corning glass substrate by a simple wet chemical solution method at room temperature. The prepared devices contained two-dimensional (2-D) nanosheet (NS) structures, which could provide a large surface-area-to-volume ratio for UV-sensing. The ZnO and Ga-doped ZnO materials were respectively named ZPD and ZPD-G. All of the samples revealed a hexagonal wurtzite structure and grew preferentially along the (002) crystal plane. Compared with the photoluminescence (PL) spectrum of the ZPD NSs, the corresponding spectra of the ZPD-G NSs in the 380 nm region and green emission were clearly red-shifted and the number of oxygen vacancies slightly decreased. Under 380 nm UV illumination and a 3 V applied bias, the ZnO UV PDs doped with Ga elements exhibited much higher photoresponsivity and stability compared with the un-doped ZnO PDs, indicating good electrical performance. The ZPD-G samples possessed higher rise and recovery times compared with the ZPD samples; this finding could be attributed to the ability of the former to generate numerous electrons.

Visualizations of Berea sandstone pores using neutron tomography

Sandstone is a reservoir rock commonly found by oil and gas companies. Oil and gas usually trap inside the sandstone pores. A Destructive-Testing (DT) method or chemical solution method is usually used to measure the porosities of the sandstone sample. On the other hand, neutron computed tomography (NCT) can visualise and quantify all the porosities of the sandstone non-destructively. Neutron tomography is an imaging technique that employs neutron generated by a nuclear research reactor. The NCT produces cross-sectional images of the object that was used to visualise the Barea sandstone porosities distribution. The results show that each rock sample possesses connected and concentrated pores in the middle part of the rock with total porosity of ± 20%.

A Facile Chemical Solution Route to Synthesize ZnO/Graphene Composite and the Improved Photocatalytic Property

ZnO/graphene composite was synthesized through a facile and economical chemical solution method at moderate temperature of 90 °C. The as-synthesized composite was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectrum. Results indicated that in the growth process graphene oxide was reduced to graphene, in which ZnO was embedded in the form of nanoparticles. As an application, the photocatalytic performance of the composite was investigated using the methylene blue (MB) in aqueous solution under ultraviolet (UV) light irradiation. The photocatalytic experiment showed that the as-synthesized ZnO/graphene composite exhibited improved photocatalytic property in comparison with that of the pure ZnO powder.

Synthesis and Characterization of Cu2O Nanofluid

<p>This research paper objects is synthesis and characterization of Cu2O nanofluid by using the chemical solution method. Characterization includes Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM). The absorption peaks of FTIR spectrum can express the characterization of Cu2O nanofluids. The SEM image graph can be expressed size d shape of the Cu2O sample on the surfactant and pH of the mixture solution respectively. Cu2O Nanofluids will be studied for their thermal conductivity and their electrical, magnetic and optical properties.</p>

Performance of Graphene–CdS Hybrid Nanocomposite Thin Film for Applications in Cu(In,Ga)Se2 Solar Cell and H2 Production

A graphene–cadmium sulfide (Gr–CdS) nanocomposite was prepared by a chemical solution method, and its material properties were characterized by several analysis techniques. The synthesized pure CdS nanoparticles (NPs) and Gr–CdS nanocomposites were confirmed to have a stoichiometric atomic ratio (Cd/S = 1:1). The Cd 3d and S 2p peaks of the Gr–CdS nanocomposite appeared at lower binding energies compared to those of the pure CdS NPs according to X-ray photoelectron spectroscopy analyses. The formation of the Gr–CdS nanocomposite was also evidenced by the structural analysis using Raman spectroscopy and X-ray diffraction. Transmission electron microscopy confirmed that CdS NPs were uniformly distributed on the graphene sheets. The absorption spectra of both the Gr–CdS nanocomposite and pure CdS NPs thin films showed an absorption edge at 550 nm related to the energy band gap of CdS (~2.42 eV). The Cu(In,Ga)Se2 thin film photovoltaic device with Gr–CdS nanocomposite buffer layer showed a higher electrical conversion efficiency than that with pure CdS NPs thin film buffer layer. In addition, the water splitting efficiency of the Gr–CdS nanocomposite was almost three times higher than that of pure CdS NPs.