Surface Analysis of Perovskite Oxynitride Thin Films as Photoelectrodes for Solar Water Splitting.

Perovskite oxynitride semiconductors have attracted huge interest recently as promising photoelectrode materials for photoelectrochemical (PEC) water splitting. Depicted by, the extensive studies of the PEC activity of oxynitride powder-based photoelectrodes and/or deposited thin-film electrodes. High-crystalline-quality, oxynitride thin films grown by physical vapor deposition are ideal model systems to study the fundamental physical and chemical properties of the surface of these materials, including their evolution. In this work, using a combination of high-sensitivity low-energy ion scattering (LEIS) and X-ray photoelectron spectroscopy (XPS), we monitor surface evolution of LaTiOxNy (LTON) and CaNbOxNy (CNON) thin films before and after the PEC characterizations. The as-prepared epitaxial LTON films show a preferential LaO termination at the surface layers, followed by a Ti-enriched subsurface. Whereas, the polycrystalline CNON thin films exhibit a non-uniform surface, with a mixed surface termination and a significant Ca-segregated subsurface. After the PEC characterizations, additional precipitated LaO species are found on the outer surface of the LTON epitaxial films. However, no significant surface change is observed on the polycrystalline CNON films by LEIS. The XPS analysis shows, an increase of the oxidized Ti and Nb cations (Ti4+ and Nb5+) after the PEC reaction in the LTON and CNON films, respectively. The initial drops in photocurrent for the LTON and CNON films are attributed to the changes in the surface chemical status. This work provides insight into the surface characteristics and evolution of LTON and CNON oxynitride thin films as photoelectrodes for PEC applications.

Nanostructured manganese oxides electrode with ultra-long lifetime for electrochemical capacitors.

We describe the instantaneous fabrication of a highly porous three-dimensional (3D) nanostructured manganese oxides-reduced graphitic oxide (MnO x -rGO) electrode by using a pulse-photonic processing technique. Such nanostructures facilitate the movement of ions/electrons and offer an extremely high surface area for the electrode/electrolyte interaction. The electrochemical performance was investigated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) with 1 M KOH as the electrolyte. The as-prepared thin film electrode exhibits excellent electrochemical performance and an ultra-long lifetime by retaining 90% of the initial capacitance even after 100 000 GCD cycles at constant areal current density of 0.4 mA cm-2. We attribute this excellent lifetime performance to the conductive reduced graphitic oxide, synergistic effects of carbon composite and the metal oxides, and the unique porous nanostructure. Such highly porous morphology also enhances the structural stability of the electrode by buffering the volume changes during the redox processes.

Pulsed photoinitiated fabrication of inkjet printed titanium dioxide/reduced graphene oxide nanocomposite thin films.

This work reports a new technique for scalable and low-temperature processing of nanostructured TiO2 thin films, allowing for practical manufacturing of TiO2-based devices such as perovskite solar cells at low-temperature or on flexible substrates. Dual layers of dense and mesoporous TiO2/graphitic oxide nanocomposite films are synthesized simultaneously using inkjet printing and pulsed photonic irradiation. Investigation of process parameters including precursor concentration (10-20 wt%) and exposure fluence (4.5-8.5 J cm-2) reveals control over crystalline quality, graphitic oxide phase, film thickness, dendrite density, and optical properties. Raman spectroscopy shows the E g peak, characteristic of anatase phase titania, increases in intensity with higher photonic irradiation fluence, suggesting increased crystallinity through higher fluence processing. Film thickness and dendrite density is shown to increase with precursor concentration in the printed ink. The dense base layer thickness was controlled between 20 and 80 nm. The refractive index of the films is determined by ellipsometry to be 1.92 ± 0.08 at 650 nm. Films exhibit an energy weighted optical transparency of 91.1%, in comparison to 91.3% of a thermally processed film, when in situ carbon materials were removed. Transmission and diffuse reflectance are used to determine optical band gaps of the films ranging from 2.98 to 3.38 eV in accordance with the photonic irradiation fluence and suggests tunability of TiO2 phase composition. The sheet resistance of the synthesized films is measured to be 14.54 ± 1.11 Ω/□ and 28.90 ± 2.24 Ω/□ for films as-processed and after carbon removal, respectively, which is comparable to high temperature processed TiO2 thin films. The studied electrical and optical properties of the light processed films show comparable results to traditionally processed TiO2 while offering the distinct advantages of scalable manufacturing, low-temperature processing, simultaneous bilayer fabrication, and in situ formation of removable carbon nanocomposites.

[Construction of automatic elucidation platform for mechanism of traditional Chinese medicine].

Aim at the two problems in the field of traditional Chinese medicine (TCM) mechanism elucidation, one is the lack of detailed biological processes information, next is the low efficient in constructing network models, we constructed an auxiliary elucidation system for the TCM mechanism and realize the automatic establishment of biological network model. This study used the Entity Grammar Systems (EGS) as the theoretical framework, integrated the data of formulae, herbs, chemical components, targets of component, biological reactions, signaling pathways and disease related proteins, established the formal models, wrote the reasoning engine, constructed the auxiliary elucidation system for the TCM mechanism elucidation. The platform provides an automatic modeling method for biological network model of TCM mechanism. It would be benefit to perform the in-depth research on TCM theory of natures and combination and provides the scientific references for R&D of TCM.

Single-crystalline metal germanate nanowire-carbon textiles as binder-free, self-supported anodes for high-performance lithium storage.

Single-crystalline metal germanate nanowires, including SrGe4O9, BaGe4O9, and Zn2GeO4 were successfully grown on carbon textile via a simple low-cost hydrothermal method on a large scale. The as-grown germanate nanowires-carbon textiles were directly used as binder-free anodes for lithium-ion batteries, which exhibited highly reversible capacity in the range of 900-1000 mA h g(-1) at 400 mA g(-1), good cyclability (no obvious capacity decay even after 100 cycles), and excellent rate capability with a capacity of as high as 300 mA h g(-1) even at 5 A g(-1). Such excellent electrochemical performance can be ascribed to the three-dimensional interconnected conductive channels composed of the flexible carbon microfibers, which not only serve as the current collector but also buffer the volume change of the active material upon cycling. Additionally, the one-dimensional nanostructures grown directly on the carbon microfibers also ensure fast charge carrier (e(-) and Li(+)) transport, large surface areas, better permeabilities, and more active sites, which also contributed to the improved electrochemical performance.

Highly reversible lithium storage in hierarchical Ca2Ge7O16 nanowire arrays/carbon textile anodes.

Aligned Ca2Ge7O16 nanowire arrays were successfully grown on carbon textiles to form hierarchical 3D structures by using a facile hydrothermal method on a large scale. Typical Ca2Ge7O16 nanowires are single crystals that show preferred growth along the [001] direction. The 3D hierarchical structures were used as binder-free anodes for lithium-ion batteries, which showed the features of highly reversible capacity (900-1100 mA h g(-1) at a current density of 300 mA g(-1)), remarkable cycling stability, even over 100 cycles, and good rate capability, with a capacity of about 500 mA h g(-1) at 3 A g(-1). Furthermore, highly bendable full cells were also fabricated, which showed high flexibility, with little voltage change after bending 600 times, and superior temperature tolerance within the range 4-60 °C, thus demonstrating their promising potential for applications in high-performance lithium-ion batteries.

TCM grammar systems: an approach to aid the interpretation of the molecular interactions in Chinese herbal medicine.

ETHNOPHARMACOLOGICAL RELEVANCE: Interpreting the molecular interactions in Chinese herbal medicine will help to understand the molecular mechanisms of Traditional Chinese medicines (TCM) and predict the new pharmacological effects of TCM. Yet, we still lack a method which could integrate the concerned pieces of parsed knowledge about TCM. MATERIALS AND METHODS: To solve the problem, a new method named TCM grammar systems was proposed in the present article. The possibility to study the interactions of TCM at the molecular level using TCM grammar systems was explored using Herba Ephedrae Decoction (HED) as an example. RESULTS: A platform was established based on the formalism of TCM grammar systems. The related molecular network of Herba Ephedrae Decoction (HED) can be extracted automatically. The molecular network indicates that Beta2 adrenergic receptor, Glucocorticoid receptor and Interleukin12 are the relatively important targets for the anti-anaphylaxis asthma function of HED. Moreover, the anti-anaphylaxis asthma function of HED is also related with suppressing inflammation process. The results show the feasibility using TCM grammar systems to interpret the molecular mechanism of TCM. Although the results obtained depend on the database absolutely, recombination of existing knowledge in this method provides new insight for interpreting the molecular mechanism of TCM. CONCLUSIONS: TCM grammar systems could aid the interpretation of the molecular interactions in TCM to some extent. Moreover, it might be useful to predict the new pharmacological effects of TCM. The method is an in silico technology. In association with the experimental techniques, this method will play an important role in the understanding of the molecular mechanisms of TCM.