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The synergistic effect between MoOx and Fe markedly promoted the activity on deoxygenation of lactic acid to bio-propionic acid.

We described herein a unique dual emission switching process from o-carborane–tetraphenylethene (TPE) dyads induced by twisted intramolecular charge transfer (TICT) in the crystalline state. Two novel o-carborane–tetraphenylethylene dyads, composed of a TPE core bearing o-carborane units, were designed, synthesized and characterized. Crystalline o-1 and o-2 were obtained with mono-substituted and bi-substituted o-carborane units, respectively. Both dyads presented locally excited (LE) emission and TICT induced emission in solutions. Crystalline o-1 demonstrated aggregation-induced emission (AIE), crystallization-induced emission (CIE), thermochromism, vapochromism, and mechanical luminescence (MCL) properties via TICT, while crystalline o-2 showed only the AIE and CIE properties orginating from the inherent ICT states. From the mechanistic investigations and theoretical calculations, it was demonstrated that the emission was reversible and switchable between green and orange colors for o-1, which was assigned to the facile TICT modulation in the solid state. The results manifest that the unique three-dimensional o-carborane cluster's structure plays an important role in precisely controlling the molecular packing patterns and conformations to achieve TICT emission.

Germanium (Ge) has been considered as a promising anode material for Li-ion batteries because of its theoretical capacity (1600 mA h g−1). However, its poor electrochemical performances resulting from the large volume variation during Li–Ge alloy/dealloy processes prevent its practical application. Herein, we designed a 3D core/shell structure by encapsulation of Ge in a sulfur (S) and nitrogen (N) co-doped three-dimensionally (3D) interconnected macroporous carbon matrix (denoted as Ge@S,N-3DPC). The 3D porous structure can not only buffer the volume change during alloy/dealloy processes, but also facilitate the electrolyte to soak in, offering fast ion/electron pathways. What's more, the co-doping of S and N in carbon could introduce more defects and active sites, which can also help to improve the interfacial adsorption and electrochemical behaviors. When used as an anode material for LIBs, the Ge@S,N-3DPC shows excellent electrochemical performances (1000 mA h g−1 at 200 mA g−1), outstanding cycling stability (94% capacity retention after 300 cycles) and high rate capability (358 mA h g−1 at 10 A g−1). This work develops a general strategy to improve the electrochemical performance of these alloy-type electrode materials with huge volume change in the energy storage area.

Solvent-dependent self-assemblies of an amphiphilic molecule based on perylene bisimide were employed in the fabrication of well-defined millimeter long nanorods and high density nanofibers, respectively. Moreover, the fabricated memory device demonstrated good behaviours with a low operating voltage, high ON/OFF ratio, long retention time, and good stability.

The already established technique of pulsed glow discharge spectroscopy is extended in these studies to the application of a second pulse applied at a variable delay after a first pulse. The net discharge then consists of a series of double pulses in which each second pulse in the series enhances the emission intensity of the analyte atoms produced by the first pulse. A copper hollow cathode is used to show high emission enhancement for atom and ion lines of the sputtered species and the neon discharge gas species. The technique shows promise for further study by both atomic emission and mass spectrometry.

The development of microsecond pulsed glow discharge atomic emission spectrometry (GD-AES) for quantitative depth profile analysis is described. The quantification method, which is based on sputtering rates, has been previously applied to depth analysis employing a dc glow discharge source. Optimal conditions of the glow discharge source, including voltage, pressure, pulse width and pulse frequency, are utilized in order to give the best depth resolution. Pulsed operation of the glow discharge affords the advantages of two additional parameters, pulse width and pulse frequency, which allow better control over the amount of sample being removed via cathodic sputtering. This allows thin layer samples to be analyzed that are very difficult using the dc source. Under the optimized parameters, thin coatings of varying depths of Cu deposited on steel were quantified. The quantitative method predicted Cu deposition depths in accord with the nominal depths.

A Grimm-type glow discharge ion source has been constructed for a time-of-flight mass spectrometer (TOF-MS). This source was operated in the microsecond-pulsed mode. Special features of pulsed Grimm GD-TOF-MS are described, including resolving power, stability, sensitivity and the temporal separation of discharge gas species and analyte ions. The analytical characteristics of a pulsed Grimm GD-TOF-MS system were also evaluated. These preliminary studies demonstrate the potential of this technique for the elemental analysis for solids.

A high voltage, microsecond regime, pulsed glow discharge has been applied to a standard Grimm type source on a LECO SA-2000 multichannel optical spectrometer. The spectrometer system has been equipped with fast time-resolved electronics in order to study the temporal response of the elemental emission lines. The aim of the research was to investigate possible gains in signal-to-background ratio (S/B) and detection limits compared to a conventional direct current (dc) mode of operation. It was found that the high instantaneous pulse power in itself gives approximately a factor 2 increase in S/B. By utilising time-resolved detection, gains in the range 5–10 are achieved. For nitrogen, it was found that the background from leakage of air could be reduced to approximately 1/3 compared with the dc mode. Another interesting observation was that certain nearly non-conducting materials, which cannot be run in dc mode, could be run in the microsecond pulsed mode.

Investigations have been performed using microsecond pulsed glow discharge atomic emission spectrometry (GD-AES) to determine the effect of the glow discharge parameters, including applied pulse voltage, pulse width, pulse frequency and gas pressure, on the resolution of depth profiling. The results indicate that a concave crater profile is obtained for low voltage, whereas the curvature is convex for high voltage. The criteria of a flat crater bottom and good depth resolution are fulfilled only with a limited range of voltages at each operating pressure. The results also imply that the pulse frequency and pulse width have little effect on the resolution of depth profiling; thus a wide dynamic range of layers from several nanometers to tens of micrometers can be analyzed by increasing or decreasing the pulse frequency and width. Under the optimized parameters, a thin coating of Cu (50 nm) on steel, an electroplated steel and a computer hard-disk with multiple thin layers were analyzed.

A high voltage, microsecond regime pulse dc glow discharge was applied to a standard Grimm source on a modified LECO SA-2000 direct reader spectrometer and to a duplicate Grimm source coupled to a scanning monochromator. The effects of experimental conditions, including pulse voltage, pulse frequency, pulse width and Ar pressure, on Cu atomic and ionic emission intensities were examined and compared with continuous discharge results. The pulsed Grimm source has a higher sputtering rate, greater signal intensity and lower detection limits. The pulsed signal for atomic lines shows a different temporal response from ionic lines. Pulsed Grimm GD-AES also offers control features advantageous in the measurement of thin surface layers.