Xueyi Guo

Black Phosphorus Based Photocathodes in Wideband Bifacial Dye-Sensitized Solar Cells

Ultrasmall black phosphorus quantum dots (BPQDs) serve as the near-infrared light absorber and charge transfer layer in the photocathode of a bifacial n-type dye sensitized solar cell. Wideband light absorption and ≈20% enhancement in the light-to-electron efficiency are accomplished due to the fast carrier transfer and complementary light absorption by the BPQDs demonstrating that BP has large potential in photovoltaics.

Sulfhydryl-Modified Fe3O4@SiO2 Core/Shell Nanocomposite: Synthesis and Toxicity Assessment in Vitro

The objectives of this study are to prepare sulfhydryl-modified Fe3O4@SiO2 core/shell magnetic nanocomposites, assess their toxicity in vitro, and explore their potential application in the biomedical fields. Fe3O4 nanoparticles synthesized by facile solvothermal method were coated with SiO2 via the Stöber method and further modified by the meso-2,3-dimercaptosuccinic acid (DMSA) to prepare Fe3O4@SiO2@DMSA nanoparticles. The morphology, structure, functional groups, surface charge, and magnetic susceptibility of the nanoparticles were characterized by transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy, zeta potential analysis, dynamic laser scattering, and vibrating sample magnetometer. Cytotoxicity tests and hemolysis assay were also carried out. Experimental results show that the toxicity of sulfhydryl-modified Fe3O4@SiO2 core/shell nanoparticles in mouse fibroblast (L-929) cell lines is between grade 0 and grade 1, and the material lacks hemolytic activity, indicating good biocompatibility of this Fe3O4@SiO2@DMSA nanocomposite, which is suitable for further application in biochemical fields.

Mineralogical characterization and pretreatment for antimony extraction by ozone of antimony-bearing refractory gold concentrates

Abstract The mineralogical characterization of antimony-bearing refractory gold concentrates and the antimony extraction by ozone in HCl solution were investigated. The mineralogical study shows that there exist stibnite(Sb 2 S 3 ), arsenopyrite(FeAsS), pyrite(FeS 2 ) and quartz in the concentrates, and the gold is mainly (67.42%) encapsulated in sulfides. The antimony extraction by ozone in hydrochloric acid was employed and the influences of temperature, liquid/solid ratio, HCl concentration and stirring speed on the extraction of antimony were investigated. High antimony extraction (93.75%) is achieved under the optimized conditions. After the pretreatment by ozone, the antimony is recovered efficiently and the gold is enriched in the leaching residue.

Copper smelting mechanism in oxygen bottom-blown furnace

Abstract The SKS furnace is a horizontal cylindrical reactor similar to a Noranda furnace, however, the oxygen enriched air is blown into the furnace from the bottom. Mechanism model of the SKS process was developed by analyzing the smelting characteristics deeply. In our model, the furnace section from top to bottom is divided into seven functional layers, i.e., gas layer, mineral decomposition transitioning layer, slag layer, slag formation transitioning layer, matte formation transitioning layer, weak oxidizing layer and strong oxidizing layer. The furnace along the length direction is divided into three functional regions, that is, reaction region, separation transitioning region and liquid phase separation and settling region. These layers or regions play different roles in the model in describing the mechanism of the smelting process. The SKS smelting is at a multiphase non-steady equilibrium state, and the oxygen and sulfur potentials change gradually in the length and cross directions. The smelting capacity of the SKS process could be raised through reasonably controlling the potential values in different layers and regions.

Leaching kinetics of antimony-bearing complex sulfides ore in hydrochloric acid solution with ozone

Abstract The leaching kinetics of Sb and Fe from antimony-bearing complex sulfides ore was investigated in HCl solution by oxidation–leaching with ozone. The effects of temperature, HCl concentration, stirring speed and particle size on the process were explored. It is found that the recoveries of Sb and Fe reach 86.1% and 28.8%, respectively, when the reaction conditions are 4.0 mol/L HCl, 900 r/min stirring speed at 85 °C with

Designing a large scale synthesis strategy for high quality magnetite nanocrystals on the basis of a solution behavior regulated formation mechanism

The large scale synthesis of magnetite nanocrystals (MNCs) is a sine qua non for supplying the rapidly increasing demand for MNCs in biomedical applications (e.g. magnetic resonance imaging (MRI), magnetic hyperthermia and targeted drug delivery), but it is still difficult to achieve their industrial production due to the operation complexity, strict synthetic conditions and the narrow error tolerance range of existing approaches. Here, we report a facile synthetic procedure using a solvothermal route with an iron acetylacetonate (Fe(acac)3), oleic acid (OA) and oleylamine (OAm) reaction system on a large scale, which is designed under the guidance of the solution behavior regulated formation mechanism of MNCs. Two intermediates, Fe(acac)x(OA)y and N-(cis-9-octadecenyl)-oleamide (OOA), are found to play key roles in adjusting the surface protection status of MNCs and the reducibility of the reaction system. With diverse combinations of surface protection status and reducibility, the final size of MNCs changes from 6.8 nm to 37.4 nm, and the morphology of the MNCs transforms from triangular prismatic to spherical (or quasi spherical), which indicates that the formation of MNCs with distinct sizes and morphologies is attributed to experiencing different pathways from nucleation to growth. Moreover, the reaction system is insensitive to the reaction temperature (220–240 °C) and time (2–6 hours), exhibiting a preferable operation error tolerance range for industrial application. Accordingly, a large scale synthesis is applied for synthesizing high quality MNCs, and 6 grams of spherical and monodispersed MNCs with a diameter of 11.2 ± 0.8 nm are obtained in a single reaction.