Atomic Interface-Exciting Catalysis on Cobalt Nitride-Oxide for Accelerating Hydrogen Generation.

The rational design of the interface structure between nitride and oxide using the same metallic element and correlating the interfacial active center with a determined catalytic mechanism remain challenging. Herein, a Co4 N-Co3 O4 interface structure is designed to determine the effect of interfacial active centers on hydrogen generation from ammonia borane. An unparalleled catalytic activity toward H2 production with a turnover frequency up to 79 min-1 is achieved on Co4 N-Co3 O4 @C catalyst for ten recycles. Experimental analyses and theoretical simulation suggest that the atomic interface-exciting effect (AieE) is responsible for the high catalytic activity. The Co4 N-Co3 O4 interface facilitates the targeted adsorption and activation of NH3 BH3 and H2 O molecules to generate H* and H2 . The two active centers of Co(N)* and Co(O)* at the Co4 N-Co3 O4 interface activate NH3 BH3 and H2 O, respectively. This proof-of-concept research on AieE provides important insights regarding the design of heterogeneous catalysts and promotes the development of the nature and regulation of energy chemical conversion.

Ru@Carbon Nanotube Composite Microsponge: Fabrication in Supercritical CO2 for Hydrogenation of p-Chloronitrobenzene.

Novel heterogeneous catalysts are needed to selectively anchor metal nanoparticles (NPs) into the internal space of carbon nanotubes (CNTs). Here, supercritical CO2 (SC-CO2) was used to fabricate the Ru@CNT composite microsponge via impregnation. Under SC-CO2 conditions, the highly dispersive Ru NPs, with a uniform diameter of 3 nm, were anchored exclusively into the internal space of CNTs. The CNTs are assembled into a microsponge composite. The supercritical temperature for catalyst preparation, catalytic hydrogenation temperature, and time all have a significant impact on the catalytic activity of Ru@CNTs. The best catalytic activity was obtained at 100 °C and 8.0 MPa: this gave excellent selectivity in the hydrogenation of p-chloronitrobenzene at 100 °C. This assembly strategy assisted by SC-CO2 will be promising for the fabrication of advanced carbon composite powder materials.

The study of zirconium vanadate as a cathode material for lithium ion batteries.

The electrochemical properties of ZrV2O7 (ZVO) and ZVO@C were investigated in lithium ion batteries. The first charge (or discharge) specific capacity of ZVO and ZVO@C are 279 mA h g-1, 392 mA h g-1, 208 mA h g-1 and 180 mA h g-1 for 0%, 3%, 5% and 9% of carbon, respectively. The capacity retention rates (with 0% 3%, 5% and 9% carbon content) are 33.0%, 52.5%, 56.4% and 76.1% after ten cycles, respectively. The low inner resistance relates to the good contact of the electrode rather than the high content of carbon, and the specific capacity retention rate increases with the increase of the carbon content.

Structure and Negative Thermal Expansion in Zr0.3Sc1.7Mo2.7V0.3O12.

A2M3O12-based materials have received considerable attention owing to their wide range of negative thermal expansion (NTE) and chemical flexibility toward novel materials design. However, the structure and NTE mechanism remain challenging. Here, Zr4+ and V5+ are used as a unit to compensatorily replace Sc3+ and Mo6+ in Sc2Mo3O12 to tune its thermal expansion. Its crystal structure, phase transition, NTE property, and corresponding mechanisms are studied by high-resolution synchrotron X-ray diffraction, powder X-ray diffraction, ultralow-frequency Raman spectroscopy, and density functional theory calculations. The results show that Zr0.3Sc1.7Mo2.7V0.3O12 adopts an orthorhombic (Pbcn) structure at room temperature, with V atoms occupying the position of Mo1 atoms and Zr atoms occupying the position of Sc atoms, and transforms to monoclinic (P21/a) structure at ∼133 K (45 K lower than that of Sc2Mo3O12). It exhibits excellent NTE in a broader range. Most of the phonon modes below 350 cm-1 have negative Grüneisen parameters, of which the lowest and next-lowest frequency (38.5 and 45.8 cm-1) optical phonon modes arising from the translational vibrations of the Sc/Zr and Mo/V atoms in the plane of the nonlinear linkage Sc/Zr-O-Mo/V have the largest and next-largest negative Grüneisen parameters and positive total anharmonicity, and contribute most to the NTE.

Structural, vibrational and thermal expansion properties of Sc2W4O15.

A novel oxide material with the formula of Sc2W4O15 and orthorhombic symmetry is synthesized by solid state reactions and its structure, composition, vibrational properties and thermal expansion are investigated and identified by temperature-dependent X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray photoelectron spectrometry (XPS) and dilatometry. It is shown that the oxide material with an orthorhombic symmetry shows a similar structure to that of Sc2W3O12, but with W partially occupying the position of Sc, leading to not only the corner-sharing ScO6-WO4 connections but also the corner-sharing WO6-WO4 connections. Raman spectroscopic studies show that compared to Sc2W3O12, the FWHMs of most Raman modes in Sc2W4O15 increase due to the occupation of W6+ in the Sc3+ position. Besides, the W-O bonds in Sc2W4O15 are slightly harder than those in Sc2W3O12. An intrinsic thermal contraction in a wide range of temperatures (93-572 K) is demonstrated, which is attributed to the librational and translational vibrations of the corner-sharing polyhedra as well as the transverse vibrations of the bridging O atoms in the Sc-O-W and W-O-W linkages.

Near-Zero Thermal Expansion and Phase Transitions in HfMg1-x Zn x Mo3O12.

The effects of Zn2+ incorporation on the phase formation, thermal expansion, phase transition, and vibrational properties of HfMg1-x Zn x Mo3O12 are investigated by XRD, dilatometry, and Raman spectroscopy. The results show that (i) single phase formation is only possible for x ≤ 0.5, otherwise, additional phases of HfMo2O8 and ZnMoO4 appear; (ii) The phase transition temperature from monoclinic to orthorhombic structure of the single phase HfMg1-x Zn x Mo3O12 can be well-tailored, which increases with the content of Zn2+; (iii) The incorporation of Zn2+ leads to an pronounced reduction in the positive expansion of the b-axis and an enhanced negative thermal expansion (NTE) in the c-axes, leading to a near-zero thermal expansion (ZTE) property with lower anisotropy over a wide temperature range; (iv) Replacement of Mg2+ by Zn2+ weakens the Mo-O bonds as revealed by obvious red shifts of all the Mo-O stretching modes with increasing the content of Zn2+ and improves the sintering performance of the samples which is observed by SEM. The mechanisms of the negative and near-ZTE are discussed.

Avoiding the invasion of H2O into Y2Mo3O12 by coating with C3N4 to improve negative thermal expansion properties.

The hygroscopicity of Y2Mo3O12 has serious influences on its mechanic and negative thermal expansion (NTE) properties. The reported partial ion substitution for Y3+ in Y2Mo3O12 could reduce the hygroscopicity, however, the expected NTE properties disappear disappointedly. In this investigation, it is found that avoiding the invasion of crystal water and extending the NTE temperature range of Y2Mo3O12 to room temperature could be realized together by heating with CO(NH2)2. The X-ray diffraction patterns, infrared absorption spectra, scanning electron microscopy images and X-ray photoelectron spectra suggest the formation of small hydrophobic molecules (C3N4, C, etc.) coated on the surface, which could clog the microchannels in Y2Mo3O12 to avoid the invasion of crystal water. The investigation paves a way to improve the NTE properties by neglecting the influences of water molecules on the stretching vibrations of MoO4 tetrahedra and the transverse vibrations of bridge oxygen atoms.

Negative thermal expansion and broad band photoluminescence in a novel material of ZrScMo2VO12.

In this paper, we present a novel material with the formula of ZrScMo2VO12 for the first time. It was demonstrated that this material exhibits not only excellent negative thermal expansion (NTE) property over a wide temperature range (at least from 150 to 823 K), but also very intense photoluminescence covering the entire visible region. Structure analysis shows that ZrScMo2VO12 has an orthorhombic structure with the space group Pbcn (No. 60) at room temperature. A phase transition from monoclinic to orthorhombic structure between 70 and 90 K is also revealed. The intense white light emission is tentatively attributed to the n- and p-type like co-doping effect which creates not only the donor- and acceptor-like states in the band gap, but also donor-acceptor pairs and even bound exciton complexes. The excellent NTE property integrated with the intense white-light emission implies a potential application of this material in light emitting diode and other photoelectric devices.

[Absorption spectrum study of HeLa cells treated with vacuum and low-energy ions implantation].

Mineral oil was selected to protect HeLa cells from water evaporation during low-energy ions implantation in the present paper. Then, HeLa cells having been treated with vacuum and low-energy N+ ions implantation were used to collect ultraviolet absorption spectrum by spectrophotometer. Analytical results indicated that HeLa cells had some characteristic absorption peaks near 202 and 260 nm, respectively. And then the study also found: (1) The spectral intensity increased with the vacuum treatment time. In addition, the effect of vacuum on cellular spectrum was greater than that of mineral oil. (2) The influence of low energy N+ ions on absorption spectrum was far more than that of vacuum. (3) The spectral intensity increased with the implantation dose. According to these results, the effect of low-energy N+ ions implantation and vacuum on tumorous cells (HeLa cells), especially on the molecular configuration and component of tumorous cells (HeLa cells) was discussed. In a word, this study provides a basis for further research on the functionary mechanism of low-energy ions implantation on biomaterial.

[Study the Raman spectroscopy of breast tumor limbic tissue].

The confocal Raman micro-spectra of breast tumor limbic fat tissues of forty cases after surgery were collected. Substantial differences were found among breast infiltrative ductal carcinoma, hyperplasia and fibroadenoma, which is possibly to be used as a character of breast cancer and other breast tumor and offers the evidence for the breast tumor diagnosis. So, the Raman spectroscopy of the breast limbic fat tissue is of great value.

[Study on absorption spectra of malignant plasma of esophagus].

There are too many articles about diagnosing cancers by the content of tumor chemical signs in plasma, but there are few articles about diagnosing them by spectroscopy. The present article belongs to the few. The authors can differentiate the normal and malignant esophagus by the statistic and analysis of absorption spectra after their plasmas are detected by spectrophotometry, which provide a new approach to quickly diagnosing malignant esophagus.

[Fuzzing pattern recognition study on Raman spectrum of tumor peripheral tissue].

On the basis of some theories about fuzzing pattern recognition, the present article studied the data preprocessing of the Raman spectrum of tumor peripheral tissue, and feature extraction and selection. According to these features the authors improved the leaning towards the bigger membership function of trapezoidal distribution. The authors built the membership function of Raman spectrum of tumor peripheral tissue which belongs to malignant tumor on the basis of 40 specimens, and designed the classifier. The test of other 40 specimens showed that the discrimination of malignant tumor is 82.4%, while that of beginning tumor is 73.9%.

[Effect of cancer cells on the spectra of serums].

This article studied the different effects on the spectra of serums by adding different amount of cancer cells into serum, and gives the comparison between CNE cells' serum spectra and Hela' as well as that between abnormal serums and normal ones. Experiment results showed that the intensity of the absorption spectra and the fluorescence spectra exhibits a trend that it increases with the decrease in the cancer cells' number, while begins to drop when it goes up to a certain extent. The intensity of the normal serums' spectra is obviously higher than that of the abnormal one. It is concluded that the changes in the intensity of fluorescence spectra' show that the cancer cells restrain the vibration of some group in the normal serums, and the absorption spectra' reveal that the cancer cells prevent the casein from absorbing light.

[The study of absorption spectrum for cell substrate].

The authors collected the absorption spectrum of RPMI 1640 and DMEM substrates that cultivated Hela and CNE by UV-3101 spectrophotometer and analysed the absorbability of proteins in the substrate. The absorption peaks of the RPMI 1 640 culture medium that cultivated cells for different times shifted from 227 to 222 or 218 nm and from 278 to 280 nm respectively; while during growing course of cultivated cells, one of the absorption peaks of DMEM culture medium shifted from 224 nm to one near 221 nm, and the absorption peak 278 nm almost had no shift. All of these shifts show that the content of each amino acid such as tryptophan and casein has already changed. That is, during the growing course of cultivating cancer cells, the tryptophan and casein were not depleted equivalently. In the growth period of Hela and CNE, they consumed different amino acid. So they need different component proportion for amino acid.