Selective preparation of zero- and one-dimensional gold nanostructures in a TiO2 nanocrystal-containing photoactive mesoporous template

Nanocrystallized SiO2-TiO2 with tubular mesopores was prepared via the sol-gel technique. Gold was deposited in the tubular mesopores of the nanocrystallized SiO2-TiO2. The shape of the gold was varied from one-dimensional [1-D] to zero-dimensional [0-D] nanostructures by an increase in TiO2 content and ultraviolet [UV] irradiation during gold deposition. 1-D gold nanostructures [GNSs] were mainly obtained in the mesopores when a small amount of TiO2-containing mesoporous SiO2-TiO2 was used as a template, whereas the use of a template containing a large amount of TiO2 led to the formation of shorter 1-D or 0-D GNSs. UV irradiation also resulted in the formation of 0-D GNSs

Electrophoretic deposition of Ag nanoparticles into TiO2 nanotube arrays and their performance as photoanode of dye-sensitized solar cells

Dye-sensitized solar cells (DSSCs) are known as next-generation solar cells because their production process costs low and is environmentally friendly compared to silicon-type solar cells, which are currently most widely used in the world. However, power conversion efficiency (PCE) of DSSCs is still lower than 12%, which is much lower than that of silicon-type solar cells. Since one of the main reasons of such a low PCE of DSSCs is a weak light absorption ability of dye molecules, researchers have been studying to improve the light harvesting ability of DSSCs by, for instance, producing new dyes, designing new DSSC structures, adding light absorbing/scattering elements/materials, etc. The addition of metal nanoparticles (NPs) to an photoanode is one of the ways to improve light harvesting ability of DSSCs, because the NPs exhibit surface plasmon resonance (SPR) which absorb and scatter light strongly. SPR is a collective oscillation of free electrons of metal, thus strong electro-magnetic (EM) field is created near the surface of metal NPs. The electrons of dyes can be easily excited by the enhanced EM field and thus the PCE of DSSCs improved. However, the improvement of PCE of DSSCs by metal NPs is generally not as high as expected, because it is difficult to control dispersion state of metal NPs in an photoanode. In this work, Ag NPs were used as metal NPs because Ag NPs are known to create the strongest EM field by SPR among all metals. Anodic TiO2 nanotube (TNT) arrays were employed as a photoanode since the morphology of TNT arrays is known to be appropriate to reduce an electrical resistivity at photoanode. Several methods of Ag NP deposition on TNT arrays were investigated for controlling the dispersion state of Ag NPs Please click Additional Files below to see the full abstract

EPD FOR COMPOSITE CATHODE LAYER IN ALL-SOLID-STATE LITHIUM ION BATTERY BASED ON SULFIDE ELECTROLYTE

All-solid-state lithium ion batteries (LIBs), in which liquid-organic electrolytes are replaced with solid state inorganic electrolytes, are expected to be the optimal rechargeable batteries in the next generation because of their higher energy density, cycle stability and ignition safety. In order to develop all-solid-state LIBs with practical performance, controlling architecture in electrode layer consisting of active materials and solid electrolyte, to obtain good contact of the solids interfaces, with high packing ratio is necessary. However, there are few studies on controlled fabrication of macrostructure. We would like to propose a novel method which is employs electrophoretic deposition (EPD) for preparing composite cathode layer, with LiNi1/3Mn1/3Co1/3O2 (NMC) and 75Li2S-25P2S5 (LPS) used as the cathodic active material and solid electrolyte, respectively. The EPD technique can be used to prepare a cathodic layer with a desired structure because its equipment set up is simple but can be used to obtain complex composite structures. Please click Additional Files below to see the full abstract

Effects of cesium-substituted silicotungstic acid doped with polybenzimidazole membrane for the application of medium temperature polymer electrolyte fuel cells

Inorganic-organic composite membranes were prepared by using partly cesium-substituted silicotungstic acid (CHS-WSiA) and polybenzimidazole (PBI, MRS0810H) for medium temperature polymer electrolyte fuel cells (MT-PEFCs). Cesium hydrogen sulfate (CsHSO4, CHS) and silicotungstic acid (H4SiW12O40, WSiA) were milled to obtain 0.5CHS-0.5WSiA composites by dry and wet mechanical millings. N,Ndimethylacetamide (DMAc) was used as a disperse medium in the preparation of the inorganic solid acids by wet mechanical milling and also a casting agent for fabrication of membrane. Finally, flexible and homogeneous composite membranes with several phosphoric acid doping levels (PADLs) were obtained. The wet mechanical milling using DMAc was found to effectively promote good substitution of H+ ion in WSiA by Cs+ ion of CHS and promoted the formation of smaller grain sizes of composites, compared with dry milling. A high maximum power density of 378 mWcm-2 and a good constant current stability test were obtained from a single cell test using the PBI composite membrane containing 20 wt% of 0.5CHS-0.5WSiA from wet milling and phosphoric acid doping level (PADL) of 8 mol, at 150 °C under an anhydrous condition. Wet milling CHS-WSiA crystallites were highly dispersed in PBI to give homogenized membranes and played a significant role in the enhancemance of acidity by increasing the number of proton sites in the electrolyte membrane. After the addition of CHS-WSiA into PBI membrane, the acid and water retention properties were improved and incorporated as new proton conduction path by adsorbing phosphoric acid in these composite electrolyte membranes. These observations suggest that composite membranes with 8 mol of PADL are good promising PA dopedmembranes with effective electrochemical properties for the medium temperature fuel cells

SOCS1 is essential for regulatory T cell functions by preventing loss of Foxp3 expression as well as IFN-γ and IL-17A production

SOCS1 is required to restrict IFN-γ and IL-17 expression and maintain Foxp3 expression in and function of regulatory T cells

Freshwater Sponges Have Functional, Sealing Epithelia with High Transepithelial Resistance and Negative Transepithelial Potential

Epithelial tissue — the sealed and polarized layer of cells that regulates transport of ions and solutes between the environment and the internal milieu — is a defining characteristic of the Eumetazoa. Sponges, the most ancient metazoan phylum [1], [2], are generally believed to lack true epithelia [3], [4], [5], but their ability to occlude passage of ions has never been tested. Here we show that freshwater sponges (Demospongiae, Haplosclerida) have functional epithelia with high transepithelial electrical resistance (TER), a transepithelial potential (TEP), and low permeability to small-molecule diffusion. Curiously, the Amphimedon queenslandica sponge genome lacks the classical occluding genes [5] considered necessary to regulate sealing and control of ion transport. The fact that freshwater sponge epithelia can seal suggests that either occluding molecules have been lost in some sponge lineages, or demosponges use novel molecular complexes for epithelial occlusion; if the latter, it raises the possibility that mechanisms for occlusion used by sponges may exist in other metazoa. Importantly, our results imply that functional epithelia evolved either several times, or once, in the ancestor of the Metazoa