Semiconducting M 3 (hexahydroxytriphenylene) 2 (M = Ni, Co, Cu; hexahydroxytriphenylene (HHTP)) was uniformly coated onto BiVO 4 thin films via a facile solvothermal process, and the ...photoelectrochemical performance of the BiVO 4 /M 3 (HHTP) 2 photoanodes was investigated. All three BiVO 4 /M 3 (HHTP) 2 photoanodes exhibited higher photocurrent densities than pristine BiVO 4 . This can be attributed to the formation of type-II heterojunctions, as confirmed by ultraviolet photoelectron spectroscopy (UPS) and ultraviolet-visible spectroscopy. BiVO 4 /Ni 3 (HHTP) 2 exhibited the highest photocurrent density of 4.66 mA cm −2 at 1.23 V vs. a reversible hydrogen electrode (RHE), an approximately 3.2-fold increase from that of pristine BiVO 4 . The results suggest that the type of metal ion in M 3 (HHTP) 2 affects the electrical conductivity, which significantly influences the charge transport kinetics in the photoelectrochemical reactions of BiVO 4 . The mechanism underlying the enhanced photoelectrochemical reaction was also investigated.
Control of Polyaniline Particle Shapes Jung, Woo-Hyuk; Lee, Young Moo; Jo, Nam-Ju ...
Macromolecular chemistry and physics,
June 5, 2008, Volume:
209, Issue:
11
Journal Article
Peer reviewed
Needle‐like poly(aniline p‐toluenesulfonic acid) complex aggregates were synthesized by oxidative polymerization, yielding conductivities of up to 3 S · cm−1 and maximum aspect ratios of 26. Rod‐like ...aggregates as precursors to be developed into needle‐like aggregates were obtained with 1 to 2 h APS addition time at 15 °C. Flake‐like polyanilines were prepared at −2 or +20 °C with 1.9 to 2.5 h of APS addition time, giving aspect ratios of 2 to 10. Plate‐like polyaniline aggregates emerged when xylene was added, and an optimum xylene concentration was 15 vol.‐%, giving 1.3 S · cm−1 conductivity. The polyanilines were characterized by optical microscopy, SEM and UV‐vis/NIR spectroscopy.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Reproductive disorders in cows cause economic loss in livestock farms. Reproductive diseases, such as follicular cyst, luteal cyst, endometritis, pyometra, and repeat breeding cause infertility. ...Among these diseases, endometritis and pyometra are uterine infections that are leading causes of infertility. This study was performed to investigate the causative agents of uterine diseases using bacterial culture. Bacteria were obtained from the reproductive organs (vagina, uterine cervix, and uterine horn) of dairy cow diagnosed with endometritis or pyometra, and cultured on blood agar. The colonies obtained from cultivation for 24 hours were passaged. To identify the bacteria, the colonies grown in passaged culture Gram stained and applied to an automatic biochemical microbial identification system. Escherichia coli were commonly detected in vagina, uterine cervix, and uterine horn of dairy cows diagnosed to pyometra. The cows having endometritis showed not only Escherichia coli but also Pantoea spp. and Klebsiella spp. strains. Dairy cows that were infected with Escherichia coli in uterus caused mastitis or digestive disease. These results suggest that sanitary feeding and management beforehand are needed to prevent bacterial infections
Metal-organic frameworks (MOFs) are promising materials for gas sensing but are often limited to single-use detection. We demonstrate a hybridization strategy synergistically deploying conductive ...MOFs (cMOFs) and conductive polymers (cPs) as two complementary mixed ionic-electronic conductors in high-performing stand-alone chemiresistors. Our work presents significant improvement in i) sensor recovery kinetics, ii) cycling stability, and iii) dynamic range at room temperature. We demonstrate the effect of hybridization across well-studied cMOFs based on 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP) and 2,3,6,7,10,11-hexaiminotripphenylene (HITP) ligands with varied metal nodes (Co, Cu, Ni). We conduct a comprehensive mechanistic study to relate energy band alignments at the heterojunctions between the MOFs and the polymer with sensing thermodynamics and binding kinetics. Our findings reveal that hole enrichment of the cMOF component upon hybridization leads to selective enhancement in desorption kinetics, enabling significantly improved sensor recovery at room temperature, and thus long-term response retention. This mechanism was further supported by density functional theory calculations on sorbate-analyte interactions. We also find that alloying cPs and cMOFs enables facile thin film co-processing and device integration, potentially unlocking the use of these hybrid conductors in diverse electronic applications.
In article number 2100438, Jong‐Heun Lee and co‐workers report transparent gas sensors composed of aligned one‐dimensional Au–SnO2 nanofibers with extremely low coverage, transparent electrode, and ...glass substrate, which can detect harmful NO2 at room temperature under visible light illumination or natural sunlight. The transparent sensor design enables the unnoticeable installation of gas sensors on windows without external heaters and light sources.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The lack of gas selectivity in oxide semiconductor chemiresistors has long been an obstacle to realizing discriminative detection of indoor volatile organic compounds (VOCs) with different health ...impacts. A simple and reliable algorithm to discriminate between critically harmful aromatic VOCs (benzene, xylene, and toluene) and less harmful ethanol is suggested by the simple combination of sensor signals from pure In2O3 and Au-loaded In2O3 2D inverse opal (IO) thin films prepared by heat-treating the precursor-dipped self-assembled polystyrene templates and Au deposition. The Au-loaded In2O3 IO sensor showed unprecedentedly high responses to 5 ppm ethanol (resistance ratio = 1640.2) and comparably high responses to 5 ppm benzene, p-xylene, and toluene (resistance ratio range of 674.5–1012.9). Such high gas responses were attributed to the periodically porous and thus highly gas-accessible structures, while the clear discrimination between aromatic VOCs and ethanol was achieved by tuning gas selectivity through systematic control of the size, morphology, and loading concentration of Au nano-catalysts. The results of this study can be used for reliable and precise monitoring of indoor air pollutants.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Unlike isolated beta-cells, which usually produce continuous spikes or fast and irregular bursts, electrically coupled beta-cells are apt to exhibit robust bursting action potentials. We consider the ...noise induced by thermal fluctuations as well as that by channel-gating stochasticity and examine its effects on the action potential behavior of the beta-cell model. It is observed numerically that such noise in general helps single cells to produce a variety of electrical activities. In addition, we also probe coupling via gap junctions between neighboring cells, with heterogeneity induced by noise, to find that it enhances regular bursts.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
PDF
