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Tungsten I 5700Synthesis of Single-Crystalline Potassium-Doped Tungsten Oxide Nanosheets as High-Sensitive Gas Sensors. -Single-crystalline K 0.475 WO 3 nanosheets are synthesized by heating a W foil treated with an aqueous solution of KOH, AIBN, and acetone (610°C, 2 h). The as-grown products are characterized by SEM, EDX, SAED, TEM, and powder XRD. The width of the nanosheets reaches 30 µm and thicknesses of about 80 nm. The as-prepared nanosheets exhibit good stability, high sensitivity, and fast response times to H 2 S, acetone, and other gases, and may have promising applications as gas sensors. -(ZHANG, B.; LIU*, J.; GUAN, S.; WAN, Y.; ZHANG, Y.; CHEN, R.;

Hierarchical MnO₂ nanostructures were prepared through the reaction between KMnO₄ and oleic acid at room temperature in the surfactant-free microemulsion system. The obtained samples were characterized by powder X-ray diffraction, N₂ adsorption, scanning electron microscopy, and transmission electron microscopy. The results indicated that the flowerlike nanospheres were three-dimensional (3D) porous microstructures consisting of nanoplates. The surface area of the sample was 171.5 m(2)/g and the distribution of pore diameter lay within the range of 5-15 nm. The prepared hierarchically structured MnO₂ showed excellent adsorption capacity and rapid adsorption rate for methylene blue ions in water. The maximum adsorption capacity of methylene blue was as high as 273.9 mg/g and 97.5% of the dye was removed within initial 5 min of contact time. Compared with other adsorbents, the synthesized hierarchical MnO₂ nanostructures displayed a faster adsorption rate and higher adsorption capacity, which implied potential application for removing dye pollutants from waste water.

Enzymes have already been extensively applied to degrade various organic pollutants in industrial wastewater, and how to improve the stability and reusability of the enzymes is critical to their practical application. In this study, poly(glycidyl methacrylate-methacrylic acid), poly(GMA-MAA), microspheres were prepared by suspension polymerization, and were used as a new support to immobilize Trametes versicolor laccase. The maximum loading capacity to immobilize enzyme reached as high as 44.78 mg protein/g support. The stability and reusability of laccase were greatly improved after immobilization on the microspheres. While the immobilized laccase was used as catalyst to remove p-benzenediol from wastewater, the removal efficiency reached 88.5%.

To remedy the widespread chromium (Cr) pollution in the environment, this study mainly used the ultrasonic-assisted co-precipitation and precipitation methods to prepare FeS-modified Fe-Al-layered double hydroxide (FeS/LDH) composite material. The experimental results showed that FeS/LDH has higher removal efficiency of Cr in aqueous solution and stronger anti-interference ability than unmodified LDH. Under the same reaction conditions, the removal efficiency of total Cr(Cr(T)) using LDH was 34.85%, and the removal efficiency of Cr(VI) was 46.76%. For FeS/LDH, the removal efficiency of Cr(T) and Cr(VI) reached 99.57% and 100%, respectively. The restoration of Cr(T) and Cr(VI) by FeS/LDH satisfied the Langmuir adsorption isotherm. The maximum adsorption capacity of Cr(T) and Cr(VI) achieved 102.9 mg/g and 147.7 mg/g. The efficient removal of Cr by FeS/LDH was mainly based on the triple synergistic effect of anion exchange between Cr(VI) and interlayer anions, redox of Cr(VI) with Fe2+ and S2−, and co-precipitation of Fe3+ and Cr3+.