Synthesis of 2D hollow hematite microplatelets with tuneable porosity and their comparative photocatalytic activities

State Key Development Program for Basic Research of China [2007CB935603]; National Natural Science Foundation of China [51372212]alpha-Fe2O3 2D hollow microplatelets were synthesized by a facile one-pot template-free solvothermal method. The effect of synthetic parameters on the morphology and structure of the product was systematically studied. And the possible formation mechanism was proposed. Interestingly, by simply varying the concentration of NH4F, alpha-Fe2O3 hollow microstructures with similar platelet-like shapes but different porosities can be readily obtained. Their comparative photocatalytic activities were also investigated

Hematite concave nanocubes and their superior catalytic activity for low temperature CO oxidation

Hematite (α-Fe2O3) concave nanocubes bound by high-index {1344} and {1238} facets were synthesized and their catalytic activity for CO oxidation were also investigated. ? 2014 the Partner Organisations

Fabrication of Au/Pd alloy nanoparticle/Pichia pastoris composites: a microorganism-mediated approach

Fundamental Research Funds for Central Universities [2010121051]; NSFC projects [21106117, 21036004]Synthesis of metal nanoparticles (NPs) is in the limelight in modern nanotechnology. In this present study, bimetallic Au/Pd NP/Pichia pastoris composites were successfully fabricated through a one-pot microbial reduction of aqueous HAuCl4 and PdCl2 in the presence of H-2 as an electron donor. Interestingly, flower-like alloy Au/Pd NP/Pichia pastoris composites were obtained under the following conditions, NaCl concentration 0.9% (w/v), molar ratio of Au/Pd (1 : 2) and the time for pre-adsorption of Au(III) and Pd(II) ions 15 min, through fresh yeast reduction. The mapping results from scanning transmission electron microscopy (STEM) with a high-angle annular dark field detector confirmed that the Au/Pd NPs on the surface of the yeast were indeed alloy. Furthermore, the energy dispersive X-ray (EDX) and X-ray photoelectron spectroscopy (XPS) measurements showed that the composition of the bimetallic NPs were consistent with the initial molar ratio of the precursors

Biogenic flower-shaped Au-Pd nanoparticles: Synthesis, SERS detection and catalysis towards benzyl alcohol oxidation

～40 nm flower-shaped Au-Pd bimetallic nanoparticles were prepared in a facile and eco-friendly way based on the simultaneous bioreduction of HAuCl 4 and Na2PdCl4 with ascorbic acid and Cacumen Platycladi leaf extract at room temperature. Characterization techniques, such as transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction, were employed to confirm that the as-synthesized nanoparticles were alloys. The obtained flower-shaped Au-Pd alloy nanoparticles exhibited an excellent surface enhanced Raman spectroscopic activity with rhodamine 6G and efficient catalytic ability for the oxidation of benzyl alcohol to benzaldehyde. ? 2014 The Royal Society of Chemistry

Effect of Adjuvants on the Wetting Behaviors of Bifenthrin Droplets on Tea Leaves

The hydrophobic epicuticle wax on fresh leaves of tea tree (Camellia sinensis (L.) 0. Kuntze) leads to the loss of pesticide droplets, reducing efficacy. In this study, four adjuvants were selected to improve the diffusion and adhesion of bifenthrin droplets on the surface of tea leaves at different growth stages. The coupling effect of bifenthrin and adjuvants on the time-dependent and concentration-dependent wettability of droplets was investigated, and the difference in the wettability between bud and leaf was explained by observing the surface morphology. It was found that adjuvants effectively reduced the contact angle of droplets and accelerated the diffusion speed, and the above phenomenon became obvious with the increase in the adjuvant concentration. The wetting promotion of young leaves was more significant due to the reduced epicuticle wax and the greater roughness compared with fresh buds. The surface tension of the pesticide mixture was negatively correlated with the cosine of contact angle after adding the four adjuvants regardless of the growth stage of tea leaves. The contact angle of 0.2% Silwet L-77 decreased to 0° within 10 s, but the extreme wettability led to the decrease in adhesion with the increase in concentration. However, the wettability and adhesion on the surface of tea leaves were simultaneously suitable with more than 0.1% nonionic surfactant. The minimum concentration of the optimal adjuvant proposed in this study can provide an experimental basis and guide more efficient plant protection in tea gardens

Effect of Adjuvants on the Wetting Behaviors of Bifenthrin Droplets on Tea Leaves

The hydrophobic epicuticle wax on fresh leaves of tea tree (Camellia sinensis (L.) 0. Kuntze) leads to the loss of pesticide droplets, reducing efficacy. In this study, four adjuvants were selected to improve the diffusion and adhesion of bifenthrin droplets on the surface of tea leaves at different growth stages. The coupling effect of bifenthrin and adjuvants on the time-dependent and concentration-dependent wettability of droplets was investigated, and the difference in the wettability between bud and leaf was explained by observing the surface morphology. It was found that adjuvants effectively reduced the contact angle of droplets and accelerated the diffusion speed, and the above phenomenon became obvious with the increase in the adjuvant concentration. The wetting promotion of young leaves was more significant due to the reduced epicuticle wax and the greater roughness compared with fresh buds. The surface tension of the pesticide mixture was negatively correlated with the cosine of contact angle after adding the four adjuvants regardless of the growth stage of tea leaves. The contact angle of 0.2% Silwet L-77 decreased to 0° within 10 s, but the extreme wettability led to the decrease in adhesion with the increase in concentration. However, the wettability and adhesion on the surface of tea leaves were simultaneously suitable with more than 0.1% nonionic surfactant. The minimum concentration of the optimal adjuvant proposed in this study can provide an experimental basis and guide more efficient plant protection in tea gardens

New isolate of Trichoderma viride strain for enhanced cellulolytic enzyme complex production

Singapore Totalisation Board; Ngee Ann KongsiA new Trichoderma viride stain was isolated from Singapore soil samples. Its mutants were developed by using ethyl methyl sulfonate (EMS) treatment and UV-irradiation followed by a semi-quantitative plate clearing assay on phosphoric-acid-swollen cellulose plates. Mutant EU2-77 proved to be the most promising extracellular cellulase producer among 20 mutants in a screening program performed in shake flask fermentation after plate screening. Soluble protein content, filter paper cellulase (FPase) activity, beta-glucosidase activity and endoglucanase (CMCase) activity of the fermentation broths of the mutant strain were increased to 1.67, 2.49, 2.16, and 2.61 folds, respectively, compared with the wild strain. This enzyme complex produced by mutant EU2-77 contained FPase (2.19 IU/ml), CMCase (16.46 IU/ml), beta-glucosidase (4.04 IU/ml), xylanase (42.37 IU/ml), and beta-xylosidase (0.12 IU/ml). The soluble protein concentration in the enzyme complex was 1.69 mg/ml. The hydrolytic capacities of fermentation supernatants of T. reesei Rut-C30, the wild strain T. vi ride NP13a and mutant T. viride EU2-77 were compared with the commercial enzymes on the hydrolysis of waste newspaper. The crude enzymes prepared by T. vi ride EU2-77 showed much higher hydrolysis performance than that from the commercial strain Rut-C30 and demonstrated much comparable hydrolytic performances with the commercial enzyme mixtures. T. vi ride mutant EU2-77 produced high levels of extracellular cellulases as well as beta-glucosidase, rendering the supplementation of beta-glucosidase unnecessary in waste newspaper hydrolysis. (C) 2010, The Society for Biotechnology, Japan. All rights reserved

α-Fe2O3/Pt hybrid nanorings and their enhanced photocatalytic activities

In this paper, α-Fe2O3 nanorings were synthesized and used as a support to further synthesize hybrid Pt/α-Fe2O3 nanorings. Transmission electron microscopy (TEM) analyses clearly suggest that Pt nanoparticles are deposited on the surface of α-Fe2O3 nanorings in a well-dispersed state. This metal-semiconductor hybrid system is expected to show high photocatalytic activity towards the degradation of environmental pollutants. Because of the Schottky contact between semiconductor and metal particles, the holes prefer to localize in energetically lower semiconductor, whereas the electrons can move through the heterointerface. This interfacial charge transfer and separation facilitate the redox reactions, results in a high photocatalytic activity. In our case, the as obtained α-Fe 2O3/Pt hybrids exhibit enhanced photocatalytic performance with a degradation rate of 86.7% for methyl orange, which is much higher than that of pure α-Fe2O3 (33.2%). ? 2013 Elsevier Ltd and Techna Group S.r.l

Properties of oriented carbon fiber/polyamide 12 composite parts fabricated by fused deposition modeling

This paper reports the thermal and mechanical properties of carbon fiber (CF) reinforced polyamide 12 (PA12) composites for fused deposition modeling (FDM) process. The printable filaments of carbon fiber/PA12 composites with different mass fraction were fabricated and applied in FDM. The results indicate that the tensile strength and flexural strength of 10 wt% CF/PA12 composites are enhanced by 102.2% and 251.1% respectively. The laser-flash diffusivity analysis measurements exhibit remarkable improvements on thermal conductivity (lambda) of carbon fiber/PA12 composites. Moreover, the carbon fiber/PA12 composites mechanical properties are greatly improved. Our work presents a kind of anisotropic high performance composite for FDM. (C) 2017 Elsevier Ltd. All rights reserved

alpha-Fe2O3/Pt hybrid nanorings and their enhanced photocatalytic activities

State Key Development Program for Basic Research of China [2007CB935603]In this paper, alpha-Fe2O3 nanorings were synthesized and used as a support to further synthesize hybrid Pt/alpha-Fe2O3 nanorings. Transmission electron microscopy (TEM) analyses clearly suggest that Pt nanoparticles are deposited on the surface of alpha-Fe2O3 nanorings in a well-dispersed state. This metal semiconductor hybrid system is expected to show high photocatalytic activity towards the degradation of environmental pollutants. Because of the Schottky contact between semiconductor and metal particles, the holes prefer to localize in energetically lower semiconductor, whereas the electrons can move through the heterointerface. This interfacial charge transfer and separation facilitate the redox reactions, results in a high photocatalytic activity. In our case, the as obtained alpha-Fe2O3/Pt hybrids exhibit enhanced photocatalytic performance with a degradation rate of 86.7% for methyl orange, which is much higher than that of pure alpha-Fe2O3 (33.2%). (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved