Construction of a type-II BiVO4/BiOI heterojunction for efficient photoelectrocatalytic degradation of ß-naphthol and coal gasification wastewater under visible-light irradiation.

Herein, a novel type-II BiVO4/BiOI (BVOI) heterojunction electrode material was successfully fabricated by using a facile two-step electrodeposition approach. The experimental results revealed that BiOI nanosheets were deposited onto the surface of BiVO4 particles successfully, with the special morphology providing more active sites, which was beneficial to the improvement of PEC performance. According to the electrochemical performance tests, it could be observed that the construction of a heterojunction effectively promoted the separation of photoinduced electron-hole pairs and increased the transfer rate of surface charges. Under visible-light irradiation, the BVOI-300 photoanode possessed the highest PEC ß-naphthol degradation rate at pH = 7, which approximately reached 82%, whose corresponding kinetic constant was 1.4 and 1.5 times higher than those of pure BiVO4 and BiOI. After five cycles, the degradation rate still remained at 64.61%. The band structure of the BVOI electrode was deduced, and the PEC mechanism of the BVOI electrode was investigated through the radical trapping quenching experiments and ESR test, which indicated that the ˙OH, h+ and ˙O2- radicals were crucial active species in the PEC ß-naphthol degradation process. For the BVOI-300 working electrode, the TOC content of coal gasification wastewater (CGW) decreased from 94.44 to 54.4 mg L-1, and the removal rate reached 42.4%. GC-MS was used to identify the organic components of coal gasification wastewater, which was expected to provide reference for remedying actual gasification wastewater containing refractory organic pollutants and offer a new development direction for the treatment of actual coal chemical wastewater.

Characterization of the migration of organic contaminants in laboratory-scale groundwater polluted by underground coal gasification.

Underground coal gasification (UCG) is a promising technology, but the groundwater pollution caused by UCG is a potential risk to the environment. The measured results of the stratum in the combustion cavity resulting from UCG had proven that the combustion cavity would be filled with some UCG residues and caving rocks when UCG was finished. The pollutants in underground water around the combustion cavity include organic pollutants, inorganic pollutants, and ammonia nitrogen, and one of the primary organic pollutants is phenol. The migration and diffusion characteristics of organic pollutants (taking phenol as a representative) in the groundwater of the combustion cavity were investigated by breakthrough experiments and numerical simulations. The results show that the hydraulic conductivity of the coarse UCG residues is much higher than that of fine residues, and the hydraulic conductivity of the UCG residues with the size of - 0.15 mm and 0.15-0.3 mm are 4.68 × 10-6 m/s and 1.91 × 10-4 m/s respectively. The dispersivity λ for the migration of organic pollutants will be influenced significantly by the size of UCG residues in fractures of the combustion cavity, while the distribution coefficient Kd will not. The dispersivity of organic pollutants in the fine UCG residues is more significant than that in the coarse residues, and the λ for the two kinds of residues are 3.868 cm and 1.765 cm, respectively. The shape of the migration path slightly affects the pollutant concentration distribution along the path, but the width of a path has a more pronounced influence on the concentration distribution. In this research, the influence was formulated by a new technical term, MPWIT, which is related to transverse dispersion. Specifically, while the transverse dispersion values account for 20% and 10% of the longitudinal dispersion, respectively, the corresponding MPWIT values are 39.48 mm and 33.96 mm.

Construction of nitrogen vacant g-C3N4 nanosheet supported Ag3PO4 nanoparticle Z-scheme photocatalyst for improved visible-light photocatalytic activity.

The superior photocatalytic activity of semiconductor-based photocatalytic materials has attracted great attention. In this work, a series of novel Ag3PO4/g-C3N4-x (APO/CNx) composites with the Z-scheme structure were fabricated through a facile precipitation method. B naphthol, a typical phenolic compound, was selected to evaluate the photocatalytic activity of all as-prepared photocatalysts. The obtained APO/CNx composites exhibited excellent photocatalytic activity for degradation of B naphthol under visible-light irradiation. Experimental results showed that the degradation rate toward B naphthol could reach to 90.5% for 180 min, which was almost 3.66 times higher than pure g-C3N4, indicating that the presence of nitrogen vacancies and Z-scheme structure could efficiently improve the photocatalytic performance of pure g-C3N4. Furthermore, the results of trapping experiments and electron spin resonance (ESR) spectroscopy manifest that •O2- and •OH radicals were the predominant active substances for B naphthol degradation, and the possible mechanism of improved photocatalytic performance was elucidated. This work will provide an innovative perspective for constructing Z-scheme photocatalysts for the application of photocatalytic in the field of wastewater treatment.

Magnetic graphene-based nanocomposites as highly efficient absorbents for Cr(VI) removal from wastewater.

Due to the merits of their high adsorption and convenient separation, magnetic graphene-based composites have become a promising adsorbent in terms of wastewater treatment. However, recycling and regeneration properties of magnetic graphene-based composites are still a conundrum, which remains to be resolved. Here, Fe3O4/reduced graphene oxide (RGO) (Fe3O4/RGO) nanocomposites were synthesized by one-step solvent-thermal reduction route and used as adsorbents for water purification. It was encouraging to find that the nanocomposites possessed many intriguing properties in removing of Cr(VI) ions, including high adsorption efficiency and excellent recycling and regeneration property. The results indicated that the magnetic separation process of the Fe3O4/RGO nanocomposites only took less than 5 s and the maximum removal efficiency of Cr(VI) reached 99.9% under the optimum experimental conditions. Most significantly, the adsorption rate of Cr(VI) can still be as high as 98.13% after 10 cycles and the single recycle quality of the nanocomposites can maintain at more than 80%. As a result, the Fe3O4/RGO nanocomposites could be a potential adsorbent for removing heavy metal ions effectively, especially in environmental protection and restoration.

Hydrothermal-template synthesis and electrochemical properties of Co3O4/nitrogen-doped hemisphere-porous graphene composites with 3D heterogeneous structure.

Despite the high capacity of Co3O4 employed in lithium-ion battery anodes, the reduced conductivity and grievous volume change of Co3O4 during long cycling of insertion/extraction of lithium-ions remain a challenge. Herein, an optimized nanocomposite, Co3O4/nitrogen-doped hemisphere-porous graphene composite (Co3O4/N-HPGC), is synthesized by a facile hydrothermal-template approach with polystyrene (PS) microspheres as a template. The characterization results demonstrate that Co3O4 nanoparticles are densely anchored onto graphene layers, nitrogen elements are successfully introduced by carbamide and the nanocomposites maintain the hemispherical porous structure. As an anode material for lithium-ion batteries, the composite material not only maintains a relatively high lithium storage capacity (the first discharge specific capacity can reach 2696 mA h g-1), but also shows significantly improved rate performance (1188 mA h g-1 at 0.1 A g-1, 344 mA h g-1 at 5 A g-1) and enhanced cycling stability (683 mA h g-1 after 500 cycles at 1 A g-1). The enhanced electrochemical properties of Co3O4/N-HPGC nanocomposites can be ascribed to the synergistic effects of Co3O4 nanoparticles, novel hierarchical structure with hemisphere-pores and nitrogen-containing functional groups of the nanomaterials. Therefore, the developed strategy can be extended as a universal and scalable approach for integrating various metal oxides into graphene-based materials for energy storage and conversion applications.

Synthesis of cyclobutane-fused oxygen-containing tricyclic framework via thermally promoted intramolecular cycloaddition of cyclohexadienone-tethered allenes.

We have developed a unique approach for the thermally promoted cycloaddition of cyclohexadienone-tethered allenes to form a versatile cyclobutane-fused oxygen-containing tricyclic framework in an environmentally friendly and atomic economic fashion with high regioselectivity. The reaction encompasses a broad substrate scope and functional group tolerance of cyclohexadienone moieties. Moreover, the cycloaddition was also applicable to the late-stage functionalization of pharmaceutically relevant compounds.

Quantitative phosphoproteomic analysis of soft and firm grass carp muscle.

Fish muscle firmness is an important quality trait for consumer acceptance. Phosphorylation is known to change chemical and physical properties of proteins and is thus expected to affect muscle firmness, but only few such phosphoproteins have been identified. To explore phosphoproteins that affect fish muscle firmness, firm muscle (crisp grass carp) and soft muscle (ordinary grass carp) were analyzed by quantitative phosphoproteomics. We identified 27 up-regulated and 22 down-regulated phosphopeptides in crisp grass carp (ratio ≥1.5 or ≤0.667, and P-value < 0.05) and their potential upstream kinases. Protein-protein interaction analysis clustered these phosphoproteins into four groups, many of which have been suggested to impact muscle firmness and its postmortem changes: muscle fiber, connective tissue, carbohydrate metabolism and signal regulation. These results provide novel insights into the role of protein phosphorylation in fish muscle firmness and will contribute to the quality improvement of fish products.

Nitrogen-Doped Porous Co3O4/Graphene Nanocomposite for Advanced Lithium-Ion Batteries.

A novel approach is developed to synthesize a nitrogen-doped porous Co3O4/anthracite-derived graphene (Co3O4/AG) nanocomposite through a combined self-assembly and heat treatment process using resource-rich anthracite as a carbonaceous precursor. The nanocomposite contains uniformly distributed Co3O4 nanoparticles with a size smaller than 8 nm on the surface of porous graphene, and exhibits a specific surface area (120 m2·g-1), well-developed mesopores distributed at 3~10 nm, and a high level of nitrogen doping (5.4 at. %). These unique microstructure features of the nanocomposite can offer extra active sites and efficient pathways during the electrochemical reaction, which are conducive to improvement of the electrochemical performance for the anode material. The Co3O4/AG electrode possesses a high reversible capacity of 845 mAh·g-1 and an excellent rate capacity of 587 mAh·g-1. Furthermore, a good cyclic stability of 510 mAh·g-1 after 100 cycles at 500 mA·g-1 is maintained. Therefore, this work could provide an economical and effective route for the large-scale application of a Co3O4/AG nanocomposite as an excellent anode material in lithium-ion batteries.

miR-365 Suppresses Cholangiocarcinoma Cell Proliferation and Induces Apoptosis by Targeting E2F2.

Cholangiocarcinoma (CCA) is one of the most malignant adenocarcinomas arising from bile duct epithelial cells. However, the molecular mechanism regulating CCA development and progression still needs to be investigated. Here we found that miR-365 was downregulated in CCA tissues compared with adjacent normal tissues. By functional experiments, we found that overexpression of miR-365 significantly inhibited CCA cell proliferation and promoted cellular apoptosis in vitro. Furthermore, administration with miR-365 markedly suppressed the growth of tumor tissues in vivo. Mechanistically, we identified E2F2 as the target gene of miR-365 in CCA cells. We found that overexpression significantly inhibited the expression of E2F2 in CCA cells, and there was an inverse correlation between the expression levels of E2F2 and miR-365 in CCA tissues. We also found that E2F2 was highly expressed in CCA tissues and cell lines. Restoration of E2F2 in miR-365-overexpressing CCA cells promoted cell viability and reduced cellular apoptosis in CCA. Collectively, our study demonstrated the essential role of miR-365 and its functional mechanism in CCA cells, which provided a new insight on the design of therapeutic targets for CCA treatment.

Selective recovery of vanadium and scandium by ion exchange with D201 and solvent extraction using P507 from hydrochloric acid leaching solution of red mud.

D201 resin and P507 extractant diluted with sulfonated kerosene were used to respectively separate vanadium and scandium, and impurity ions from hydrochloric acid leaching solution of red mud. More than 99% of vanadium was selectively adsorbed from the hydrochloric acid leaching solution under the conditions of pH value of 1.8, volume ratio of leaching solution to resin of 10, and flow rate of 3.33 mL/min. Maximum extraction and separation of scandium was observed from the acid leaching solution at an aqueous pH value of 0.2. More than 99% of scandium can be selectively extracted using 15% P507, 5% TBP at the aqueous solution/organic phase (A/O) ratio of 10:1 for 6 min. The loaded organic phase was washed with 0.3 mol/L sulfuric acid, wherein most impurities were removed. After the process of desorption or stripping, precipitation, and roasting, high-purity V2O5 and Sc2O3 were obtained. Finally, a conceptual flow sheet was established to separate and recover vanadium and scandium from red mud hydrochloric acid leaching solution.