Octahedral Crystal Structure Research Articles

Structural Phase Transition and Disproportionation of MnF3 Under High Pressure and High Temperature.

Materials that once suffered under high-pressure and high-temperature conditions often display unusual phenomena that challenge traditional understanding. MnF3, an intermediate valence state Mn-F compound, exhibits a distorted octahedral crystal structure influenced by the Jahn-Teller effect. Here we report the structural phase transition and self-disproportionation of MnF3 under high pressure and high temperature. The initial octahedra phase I2/a-MnF3 transforms into the hendecahedra Pnma phase under high pressure. Subsequently, we found that molten Pnma-MnF3 self-disproportionate into MnF2 and MnF4 with the aid of laser heating at a pressure above 57.1 GPa. Raman spectra and UV-vis absorption experiments confirmed these changes that were ultimately confirmed by synchrotron radiation XRD. The equation of states for the volume with the pressure of these Mn-F compounds was also given. This work expands the study of Mn-F systems and provides guidance for the behavior of transition metal fluorides under high pressures and high temperatures.

Novel Carbon-Coated Zirconium (IV) Oxide Nanocomposite for the Electrochemical Determination of Rutin

ZrO2 coated highly porous biomass carbon nanocomposites (ZrO2@KHPC) were synthesized by calcination. The ZrO2 was derived from an amino-functionalized metal-organic framework and the porous biomass carbon material was derived from waste sunflower products. A selective electrochemical sensor was fabricated by modifying glass carbon electrodes (GCE) using ZrO2@KHPC to determine rutin. KHPC with a porous structure exhibited strong adsorption, high specific surface area, and superior electrical conductivity, whereas ZrO2 nanoparticles with an octahedral crystal structure and high electrocatalytic activity promote the specific recognition of rutin. The ZrO2@KHPC/GCE sensor demonstrated exceptional performance with a low detection limit of 0.008 µM and a sensitivity of 28.45 µA·µΜ−1·cm−2 from 0.01 to 40 µM. This excellent performance is attributed to the synergistic combination of ZrO2 and KHPC. In addition, the electrochemical sensor demonstrated suitable stability, good selectivity, high reproducibility, and satisfactory recovery for practical analysis.

Rapid development of Nb-BIPA-TC-MOF film based optical wave- guides for the ‘turn-on-off’ detection of acidic-basic gases

Metal-organic frameworks (MOFs), constructed from organic ligands that are rich in conjugated π bonds, have been gaining significant attention for gas sensing. This paper reports the synthesis of Nb-H2BIPA-TC, an octahedral MOF, starting from niobium as the metal centre and benzoimidephenanthroline tetracarboxylic acid (H4BIPA-TC) as the ligand. The Nb-H2BIPA-TC-MOF was grown under light irradiation on the surface of a lithium niobate waveguide substrate and assessed for its ability to sense acidic and basic gases. The Nb-H2BIPA-TC-MOF formed an octahedral crystal structure after being grown for only 20 min. The obtained film was optically transparent and featured low light attenuation (< 1.28 dB mm−1). Owing to the Lewis acid-base nature of the Nb-H2BIPA-TC-MOF, the designed sensor exhibited a specific ‘turn on-off’ sensing response to H2S, SO2, and ethylenediamine (EDA) gases. The host-guest interaction between the gas-sensitive Nb-H2BIPA-TC -MOF and different analyte gases induced different degrees of ‘on-off’ switching in its refractive index. The designed MOF showed a significant and reproducible ‘turn on-off’ response to H2S and EDA gases in the 0.1–100 ppm concentration range. The designed MOF responded to these two gases for at least 28 days with a 10–23 % reduction in the sensing response per 7 days. Owing to its low immunity to relative humidity, the designed MOF can be employed under low humidity conditions for the detection of H2S/SO2 and EDA.

Synthesis of a high-iron fly-ash-based Na-X molecular sieve and its application in the adsorption of low concentration of CO2.

In addressing the environmental challenges posed by the accumulation of fly ash (FA), efforts have been geared towards its high-value utilization. By the use of high-iron FA as a raw material, a high-iron fly-ash-based Na-X molecular sieve was successfully synthesized by hydrothermal method. We combined pretreatment methods such as high-temperature calcination, acid leaching and alkali fusion activation. The as-synthesized product was used for the adsorption of a low concentration of CO2, and the adsorption data were fitted by a physical model. The changes in iron content in pretreatment and molecular sieve synthesis were revealed by SEM-mapping, UV-Raman and UV-Vis. The results showed that the pretreatment process reduces the iron content from 32.3% to 13.3%, and converts the inactive phases to active phases, with n (SiO2/Al2O3) = 4.94. The activated product was transformed further to a Na-X molecular sieve using a hydrothermal method. The product has a single crystal phase and octahedral crystal structure. Its specific surface area was 646.634 m2 g-1, and micropores were distributed between 0.46 nm and 0.71 nm, with a mesoporous phase of 4.6 nm. When used to adsorb a low concentration of CO2, the Na-X molecular sieve has a high adsorption capacity of 3.70 mmol g-1, which reaches 95.11% that of the commercial Na-X molecular sieve. The adsorption breakthrough time and adsorption capacity decreased with an increase in temperature. The adsorption kinetics were consistent with the Bangham model for surface pore adsorption and Weber-Morris model for internal diffusion. During the synthesis process, iron was converted from highly dispersed iron oxide to four-coordinated framework iron. Thus, this paper paves a path for the high-quality transformation and utilization of high-iron fly-ash.

Electrical Properties of Vanadium-doped LiNi0.5Mn1.5O4 as Cathode Materials for High Voltage for Lithium- ion Batteries

The spinel based LiNi0.5Mn1.5O4 cathode material shows noteworthy advantages despite its inherent disadvantages. To overcome the weaknesses they have, they are challenged to get superior materials. This was carried out on the LiNi0.5Mn1.5O4 cathode material synthesized by doped vanadium metal elements into Nickel using the solid-state method, emphasizing the specific composition LiNi0.5-xVxMn1.5O4 (x=0.05) (y = 0.05), and sintering results at 600°C produces the expected single-phase structure in the Fd-3m space group. XRD analysis revealed the characteristic octahedral crystal structure of spinel type. SEM scanning showed non-uniform grain sizes (&lt;10 □ m), indicating the possibility of grain coalescence caused by the sintering process. Additionally, irregular pore sizes were observed, potentially affecting conductivity. The activation energy obtained using Impedance Spectroscopy shows that all the prepared cathode materials are classified as semiconductors with an activation energy of about 0.13 eV, indicating good conductivity of the cathode materials.

Preparation and properties of UiO-66 based hybrid materials via surface initiated metal-free ATRP

A metal-organic framework (MOFs) material UiO-66-Br was synthesized via hydrothermal method, and the surface initiated metal-free atom transfer radical polymerization (SI-metal-free ATRP) of methyl methacrylate (MMA) and Eu complex were initiated on UiO-66-Br surface with UiO-66-Br as initiator and 10-phenylphenthiazine (PTH) as catalyst, and UiO-66 based hybrid materials (UiO-66-g-PMMA and UiO-66-g-PMMA-co-Eu complex) were obtained. The materials were characterized by fourier infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD) thermogravimetry analysis (TGA), gel permeation chromatography (GPC), scanning electron microscopy (SEM) and so on. The results showed that the MOFs material UiO-66-Br with octahedral crystal structure was successfully synthesized, the PMMA and Eu complex chains were successfully grafted from the surface of the UiO-66-Br, the polymer grafting rate of UiO-66-g-PMMA reached 3.01 %, and the Eu content of UiO-66-g-PMMA-co-Eu complex reached 11.81 %. Water wettability test indicated that the contact angles of the hybrid materials were 155.4° and 153.3° respectively. The oil-water separation and self-cleaning experiment confirmed that the UiO-66 based hybrid materials had good oil-water separation and self-cleaning properties.

Polyethylene glycol and chitosan functionalized manganese oxide nanoparticles for antimicrobial and anticancer activities

Biocompatible polymer-functionalized magnetic nanoparticles could offer promising applications in biomedical sciences. We fabricated polymer functionalized tri-manganese tetra oxide (Mn3O4) nanoparticles with the co-precipitation method and an octahedral crystal structure having a crystallite size of 10–17 nm was identified via XRD analyses. The SEM graph depicted the non-uniform and smooth surface of PEG-functionalized Mn3O4 NPs as compared to Mn3O4 and chitosan-coated Mn3O4 NPs. Elemental composition in the prepared sample was examined by EDX analysis. Various modes such as MnO, MnOH, OH, symmetric, and anti-symmetric of CH2 attached to the spectrum of Mn3O4 NPs were observed with FTIR analysis. The magnetization factor decreased and increase the coreacivity and retentivity of surface functionalized Mn3O4-NPs was calculated via VSM analysis. In-vitro bioassay, antibacterial activity was tested against Escherichiacoli, Bacillus cereus, and anti-fungal activities against two Fusarium strains indicated clear antimicrobial activities. The MTT assay to examine the anticancer activity against the MCF-7 cancer cell line was performed and the T1 MRI contrast agent demonstrated that PEG-coated Mn3O4 NPs exhibited anti-cancer activities. We propose that surface-functionalized magnetic NPs used for the treatment of cancer by using a remote controlled process of hyperthermia therapy.

Ce Site in Amorphous Iron Oxyhydroxide Nanosheet toward Enhanced Electrochemical Water Oxidation.

Iron oxyhydroxide has been considered an auspicious electrocatalyst for the oxygen evolution reaction (OER) in alkaline water electrolysis due to its suitable electronic structure and abundant reserves. However, Fe-based materials seriously suffer from the tradeoff between activity and stability at a high current density above 100mA cm-2 . In this work, the Ce atom is introduced into the amorphous iron oxyhydroxide (i.e., CeFeOx Hy ) nanosheet to simultaneously improve the intrinsic electrocatalytic activity and stability for OER through regulating the redox property of iron oxyhydroxide. In particular, the Ce substitution leads to the distorted octahedral crystal structure of CeFeOx Hy , along with a regulated coordination site. The CeFeOx Hy electrode exhibits a low overpotential of 250mV at 100mA cm-2 with a small Tafel slope of 35.1 mVdec-1 . Moreover, the CeFeOx Hy electrode can continuously work for 300h at 100mA cm-2 . When applying the CeFeOx Hy nanosheet electrode as the anode and coupling it with the platinum mesh cathode, the cell voltage for overall water splitting can be lowered to 1.47V at 10mA cm-2 . This work offers a design strategy for highly active, low-cost, and durable material through interfacing high valent metals with earth-abundant oxides/hydroxides.

Evaluation of thermal/morphological performance of SSPCM based nanoclay: Influence of the interlayer microstructure of hydrophilic and hydrophobic

The COVID-19 pandemic has led to an increase in construction energy consumption and indoor occupancy; this, in turn, has increased the demand for energy efficiency. Thermal energy storage is an effective method for energy saving and improving efficiency. In this study, improved shape-stabilized phase change materials (SSPCMs) for enhancing the energy efficiency of buildings were manufactured and evaluated. These SSPCMs were prepared via the vacuum impregnation of n-octadecane into bentonite nanoclay. Bentonite exhibits a layered tetrahedral and octahedral crystal structure with Na + cations (which feature high cation exchange capacity) in the interlayer space. The Na + ion is a hydrophilic ion that affects the properties of the interlayer. However, paraffin-PCMs are hydrophobic and have poor compatibility with water. Therefore, hydrophobicity is induced in the organic nanoclay by using an organic modifier as the PCM container. Cloisite Na + , Cloisite 15, Cloisite 20, and Cloisite 93 were used to fabricate the SSPCMs. This study compares the amount of PCM impregnated depending on the compatibility of different PCMs between hydrophilic/hydrophobic nanoclays and also evaluates the thermal performance. The observed reduction in peak temperature and the time lag effect of the PCMs confirmed that the organically modified nanoclay and the PCM composites significantly improved the amount of PCM impregnated, thermal conductivity, and latent heat characteristics. The latent heat of the hydrophobic organic nanoclay was 209% higher than that of the SSPCM-based hydrophilic nanoclay. • Composites using paraffin PCM and nanoclay were fabricated and analyzed. • Hydrophobic nanoclay showed 124% higher PCM impregnation than hydrophilic nanoclay. • It was observed that PCM impregnation was affected by the microstructure. • SSPCMs showed up to 84% improved thermal conductivity than pure PCM. • The overall thermal performance in the SSPCM based hydrophobic nanoclay were high.

Effect of carbonization temperature in the production and utilization of green carbons for chromium (VI) removal

The paper has focused on the challenges/impacts of tannery effluent and evaluates the alternative treatment options used to treat, recover or recycle chromium from the waste water. The study on performance of vetiver root biomass (VRB) powder in this study investigates the production of using chemical activation in the removal of Chromium (VI) ion from aqueous solution in continuous mode using fixed bed column. Activated carbon (VRB-AC) was prepared from the pyrolysis at different temperatures (550 ⁰C, 750 ⁰C and 900 ⁰C, 1 h)‎ using impregnated with 1:1 KOH under inert atmosphere (Nitrogen). Resulting in an activated carbon ‎with the highest surface area was chosen for subsequent studies and was characterized for its functional groups using FTIR spectrum. It can‎ be concluded that adsorbent VRB prepared using a 1:1 impregnation ratio has the highest … Spectrum. Thus, this study demonstrated ‎the potential of using VRB as cheap and efficient raw materials to produce activated ‎carbon for the treatment of industrial effluents.‎Optimal conditions for the activation stage ‎were obtained at 800 °C and a hold time of 1 h in the case of activation with carbon dioxide and at 700 °C and a ‎hold time of 1 h in the case of activation with steam. The maximum functional groups were present in ‎ VRB achieved by Nitrogen activation were of 789m2/g and 0.3268 cm3/g. The ‎characterization of materials was done using TGA, BET, XRD, SEM, and FTIR. The SEM images ofMIL-101 showed ‎octahedral crystal structure and composite materials exhibited the same morphology asMIL-101(Cr) crystals on‎an activated carbon bed. The BET surface area of AC and AC/MIL-101(Cr)5% was measured 1096.83 and‎2412.1 m2/g, respectively. A comparative study has also been done on the adsorption capacity of VRB powder of various particle sizes. It was found that the metal uptake capacity (amount of removal) of Chromium (VI) ion decreased but the adsorption capacity (percentage of removal) increased with the decrease in the concentration of chromium (VI) in the initial sample solution. It was also observed that the order of metal uptake capacity & adsorption capacity of VRB powder passing through various sieve sizes for removal of Chromium (VI) removal was as follows: 150 micron > 300 micron > 600 micron.

Effects of Lithium Salt Addition Methods on the High-Temperature Electrochemical Performance of LiMn2O4

The poor high-temperature stability of spinel LiMn2O4 cathode material has become a bottleneck hindering its large-scale application. To enhance its high-temperature electrochemical performance, the effects of two different methods of lithium salt addition on its high-temperature electrochemical performance were studied. Two methods, Li+ infiltration and solid phase mixing, were used to prepare spinel LiMn2O4 cathode material by the same high-temperature solid phase method, respectively. The obtained materials were characterized by X-ray diffraction, scanning electron microscopy, Raman, and particle size analysis. Electrochemical performance tests were carried out on the electrochemical equipment by assembling into a half-battery. The results show that the material obtained by the lithium salt solid phase mixing method presents a loose structure composed of small primary particles to form a spherical secondary particle. However, the material obtained by the Li+ infiltration method presents an octahedral crystal structure, showing a trend toward single crystal. At the same time, its calcination time is greatly shortened (from 26 to 6 h) at the same calcination temperature. The electrochemical performance test results at 55 °C show that the LiMn2O4 prepared by Li+ infiltration has a better high-temperature electrochemical performance.

Synthesis of Cu2O and Cu2O-C3N4 nanomaterials for the photodegradation of organic dyes under visible light irradiation

These experiment fabricated C3N4 powdermaterials by the calcinational method and fabricated Cu2O, Cu2O-3%C3N4, Cu2O-5%C3N4 nanomaterials by the hydrothermal method. The powdermaterials characteristics were studied by methods such as: X-ray diffraction (XRD); raman shift; scanning electron microscope (SEM); UV-vis solid absorption spectra. The photocatalytic activity of samples was studied by decomposition of methylene blue dye under visible light radiation. The results showed that the fabricated C3N4 sample was single phase with high porosity cotton structure. The Cu2O, Cu2O-3%C3N4 andCu2O-5%C3N4 samples had octahedral crystal structure with the crystal particle size was about 200-300 nm. The C3N4 doped Cu2O samples had octahedral crystal particles arranged more closely than that of Cu2O and filled in gaps by cotton, porous clusters of C3N4. The materials all had the absorption spectra expanded in the visible light region (l» 450-900 nm). The C3N4 doped Cu2O samples achieved the better photocatalytic efficiency than Cu2O and C3N4 samples in visible light region. The highest photocatalytic efficiency achieved 100% was of the Cu2O-3%C3N4 sample in the photodegradation of methylene blue dye after 30 minutes under visible light irradiation.

Plasmonic nanoparticles on metal-organic framework: A versatile SERS platform for adsorptive detection of new coccine and orange II dyes in food

Synthetic dyes have been widely applied to food processing, but abuse of colourants in food may pose risks to human health. To analyze new coccine (NC) and orange II (OII) in food, a versatile surface-enhanced Raman scattering (SERS) platform was proposed. A metal-organic framework (MOF, UiO-66(NH2)) with octahedral crystal structure was synthesized and gold nanoparticles were grown on the MOF surface to fabricate UiO-66(NH2)@Au versatile SERS platform. The UiO-66(NH2)@Au displayed much better SERS performance than gold nanoparticles with high R2 of 0.9684 for NC and 0.9912 for OII and low LOD of 0.4015 mg/L for NC and 0.0546 mg/L for OII. The recoveries of NC and OII in Mirinda soft drink and paprika ranged from 82.92 to 109.63%. This study provided a sensitive and rapid method for determination of NC and OII through UiO-66(NH2)@Au, and the proposed SERS platform revealed great potential for analyzing synthetic colourants in food samples.

Drastic enhancement in the rate and cyclic behavior of LiMn2O4 electrodes at elevated temperatures by phosphorus doping

Herein we provide an effective strategy for drastically improving the cyclic behavior and rate capability of an LiMn2O4 (LMO) electrode at elevated temperature through P element doping. The P-doped LiMn2O4 materials are characterized by X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectrometry analysis. The results show that the P element is effectively and uniformly doped within the LiMn2O4 crystal lattice and is beneficial for growth of the truncated octahedral crystal structure. The electrochemical results reveal that P doping can greatly improve the cycling performance of LiMn2O4 electrodes, especially improving the rate capability at elevated temperatures. At a high 10C rate of current density and 55 °C, the optimized LMO (1.5 wt% P) electrode shows the highest initial specific capacity of 101.2 mAh g−1, which become 74.4 mAh g−1 after 500 cycles, corresponding to 73.5% capacity retention. Under similar conditions, the LMO (2.5 wt% P) electrode shows an initial discharge capacity of 78.5 mA g−1, which become 72.2 mAh g−1 after 500 cycles, corresponding to 92.3% capacity retention.

Electronic and Optoelectronic Applications Based on ReS2

With continuous research into two‐dimensional transition metal dichalcogenides (TMDs), a great number of high‐performance devices are emerging due to the unique structures and versatile properties of TMDs. As a representative of the group‐VII TMDs, rhenium disulfide (ReS2) has attracted increasing attention because the distorted octahedral crystal structure makes it distinctive from more widely known TMDs members, such as MoS2 and WSe2. It features layer‐independent electrical and anisotropic optical properties which are suitable for the applications of field effect transistors (FETs) and photodetectors. This review focuses on the recent research work about the electronic and optoelectronic applications based on novel 2D ReS2. In the first part, the unique crystal structures and properties are introduced. This is followed by the various preparation methods. Next, high‐performance FETs and photodetectors based on ReS2 are presented. Finally, conclusions are drawn and prospects proposed.

Superior Sensor for Be2+ Ion Recognition via the Unprecedented Octahedral Crystal Structure of a One-Dimensional Coordination Polymer of Crown Fused Zinc Phthalocyanine.

The unprecedented one-dimensional (1-D) coordination polymer of crown fused zinc phthalocyanine (P-CfZnPc) with an octahedral crystal structure and with intermolecular packing that has superior multichannel sensor ability for Be2+ ion recognition was prepared and characterized by single-crystal X-ray diffraction analysis (XRD) and a wide range of spectroscopic and voltammetric methods. An exceptional feature of the crystal structure of P-CfZnPc is that each zinc ion in the phthalocyanine (Pc) polymer is coordinated by the four isoindole nitrogen atoms and an outer oxygen atom of the Pc molecule. This structure is the first example of an octahedral arrangement in a 1-D polymeric chain for zinc phthalocyanines (ZnPcs) and zinc porphyrins (ZnPs) reached without the presence of a coordinating solvent, which was confirmed by XRD analysis. Interestingly, this (1-D) coordination polymer preserves its conformation in THF (tetrahydrofuran) solution, thereby effectively preventing aggregation. This result was confirmed by the particle size of the molecule (125 nm) using dynamic light scattering (DLS) and matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectra as well as UV-vis spectroscopy. The sensor has long-term stability (more than 3 months in solution), a very low response time (less than 1 s), and nonaggregating ability, facilitating the accurate determination of ultra-trace amounts of Be2+ (lower than 1 ppb), which is extremely important in terms of human health and environmental protection. The sensor can highly selectively and sensitively bind Be2+ among Li+, Na+, K+, Cs+, Mg2+, Ca2+, Ba2+, Al3+, Co2+, Hg2+, Ni2+, Pb2+, and Zn2+ ions via Be2+-induced J aggregation of Pc molecules. Such a binding leads to not only a significant decrease in Pc absorption (677 nm) as well as the creation of new absorption (720 nm) but also fluorescence emission quenching (690 nm). Furthermore, the sensor displayed highly selective voltammetric recognition for Be2+ following J aggregation/disaggregation in the second reduction process. The binding mechanism of the sensor and Be2+ ion was also explained on the basis of TD-DFT calculations.

Activated carbon/metal-organic framework composite as a bio-based novel green adsorbent: Preparation and mathematical pollutant removal modeling

Herein, the novel green MOF's nanocomposite based on cucumber peel activated carbon (AC) and chromium-based metal-organic framework (MIL-101(Cr)) with different AC ratios (2, 5 and 10 wt%) was synthesized and used for removing Acid Green 25 (AG25) and Reactive Yellow 186 (RY186) dyes from the binary systems. The characterization of materials was done using TGA, BET, XRD, SEM, and FTIR. The SEM images of MIL-101 showed octahedral crystal structure and composite materials exhibited the same morphology as MIL-101(Cr) crystals on an activated carbon bed. The BET surface area of AC and AC/MIL-101(Cr)_5% was measured 1096.83 and 2412.1 m2/g, respectively. The results showed that the Response Surface Methodology (RSM) model predicted the actual data with high correctness. The reliability of the RSM model was validated by the high values of R2 (AG25: 0.961 and RY186: 0.957). The obtained data from this research are well-fitted with the Langmuir isotherm and the pseudo-second order kinetics. The desorption process indicates that the adsorption capacity changes are <9% after five cycles.

Effective removal of ruthenium (III) ions from wastewater by amidoxime modified zeolite X

In this study, Zeolite X was prepared by hydrothermal method, and the amidoxime group was loaded on the zeolite X to prepare amidoxime-modified zeolite X. The effective removal of ruthenium by amidoxime-modified zeolite X in simulated wastewater was investigated. The raw and modified zeolite X were characterized systematically using the BET method, the SEM, the FTIR, the XRD and the XPS to understand the physicochemical changes of the materials, and its sensitivity to Ru3+ adsorption. Batch adsorption experiments were carried out to investigate the effects of adsorbent dose, contact time, solution pH, different initial Ru3+ concentrations, temperature and the effect of competitive ions on Ru3+ adsorption. The modified zeolite X exhibited fast removal performance reaching equilibrium within 30 min at the pH of 3, and the maximum adsorption capacity was found to be 175.4 mg/g. The XRD patterns demonstrated that the modified adsorbent still has the characteristic peak of zeolite NaX, and from the SEM, it can be seen that the modified adsorbent shown the same regular octahedral crystal structure as the zeolite X. In addition, the characterization result of FTIR and XPS indicated the amidoxime group was successfully loaded onto zeolite X. Kinetic parameters were fitted by the pseudo-second order model (R2 = 0.9999), and the adsorption process by the modified zeolite X was chemical adsorption. The adsorption isotherms data of modified zeolite X were well-fitted to the Langmuir (R2 = 0.9834).In the competitive ions effect, the modified zeolite X effectively captured the Ru3+ ion in the presence of Na+ and K+. Therefore, the amidoxime-modified zeolite X could be effectively used as a potential adsorbent for Ru3+ adsorption from wastewater.

Abnormal photothermal effect of laser radiation on highly defect oxide bronze nanoparticles under the sub-threshold excitation of absorption

The mechanism of abnormal photo-thermal effect of laser radiation on nanoparticles of oxide bronzes has been proposed in this paper. The basic features of the observed effect are: a) sub-threshold absorption of laser radiation by the excitation of donor-like levels formed in the energy gap due to superficial defects of the oxide bronze nano-crystals; b) an interband radiationless transition of energy of excitation on deep triplet levels and c) consequent recombination occurring at the plasmon absorption. K or Na atoms thermally intercalated to the octahedral crystal structure of TiO2 in the wave SHS combustion generate acceptor levels in the gap. The prepared oxide bronzes of the non-stoichiometric composition NaxTiO2 and KxTiO2 were examined by high resolution TEM, and then grinded in a planetary mill with powerful dispersion energy density up to 4000 J/g. This made it possible to obtain nanoparticles about 50 nm with high surface defect density (1017–1019 cm-2 at a depth of 10 nm). High photo-thermal effect of laser radiation on the defect nanocrystals observed after its impregnation into cartilaginous tissue exceeds 7 times in comparison with the intact ones.

Carbon Dioxide Adsorption Behavior of Modified HKUST-1

A kind of typical metal-organic frameworks (MOFs) material, HKUST-1 was prepared by hydrothermal method and characterized by XRD and SEM. The results of characterizations manifested that HKUST-1 showed a regular octahedral crystal structure. The as-prepared HKUST-1 was modified by several kinds of organic base materials and the CO 2 adsorption behaviors of modified HKUST-1 materials were evaluated. The CO 2 adsorption capacities of different base modified HKUST-1 varied with the base intensity of modified organic base materials.