Shape-controlled synthesis and photocatalytic activity of In2O3 nanostructures derived from coordination polymer precursors

In（BTC）（phen）（H₂O）nanocrystals with controllable morphology and size were successfully obtained by solvothermal method.Hierarchical straw-sheaf-like architectures,nanorods and elongated hexagons have been synthesized by varying the volume ratio of DMF:H₂O:C₂H₅OH.Phase-pure In₂O₃nanocrystals were obtained by the calcination of the precursors without significant alteration of the morphology.The products were characterized by PXRD,SEM,TEM,TGA,IR and gas adsorption measurements.The photocatalytic effect was investigated for the In₂O₃ nanocrystals with different morphology on the degradation of rhodamine B（Rh B）and it was found that the nanorods exhibited the best photocatalytic activity,which shows the degradation efficiency of 94%for 8 h.The results showed that the photocatalytic activity increased with the increase of BET surface area and pore volume.     

BTC/DMF辅助的1-取代苯基-3,4-二取代吡唑类衍生物的合成

室温条件下,以各种取代苯肼和环状酮为起始原料,经脱水成腙和Vilsmeier试剂(BTC/DMF)环合两步反应合成了1-取代苯基-3,4---取代吡唑类衍生物(4a～4i),其结构经1H NMR,13C NMR,IR和MS表征,其中4b,4c,4e,4f和4h为新化合物.     

Evaluation of copper-1,3,5-benzenetricarboxylate metal-organic framework (Cu-MOF) as a selective sorbent for Lewis-base analytes

The metal-organic framework copper-1,3,5-benzenetricarboxylate (Cu-BTC) was evaluated for its ability to selectively interact with Lewis-base analytes by examining retention on gas-chromatographic columns packed with Chromosorb W HP that contained 3.0% SE-30 along with various loadings of Cu-BTC. Scanning electron microscopy images of the support material showed the characteristic Cu-BTC crystals embedded in the SE-30 coating on the diatomaceous support. The results indicated that the Cu-BTC-containing stationary phase had limited thermal stability (220 °C) and strong general retention for analytes. Kováts index calculations showed selective retention (amounting to about 300 Kováts units) relative to n-alkanes for many small Lewis-base analytes on a column that contained 0.75% Cu-BTC compared with an SE-30 control. Short columns that contained lower loadings of Cu-BTC (0.10%) allowed elution of nitroaromatics; however, selectivity was not observed for aromatic compounds (including nitroaromatics) or nitroalkanes. Observed retention characteristics are discussed.     

Nano/Micro HKUST-1 Fabricated by Coordination Modulation Method at Room Temperature

A simple and fast route for the synthesis of metal-organic framework(MOF) particles was presented.Cu 3(BTC) 2(HKUST-1,BTC=1,3,5-benzenetricarboxylate),one of the most well-known MOFs,was synthesized at room temperature via coordination modulation method.By adding different modulators(monocarboxylic acids) into the reaction system,the morphologies of HKUST-1 crystals were tuned from nano spheres to micro octahedrons at room temperature without any complex equipment.X-Ray diffractions and gas sorption measurements revealed highly crystalline particles with large Brunauer-Emmett-Teller(BET) surface areas(1116―1273 m 2 /g) and total pore volumes(0.62―0.73 cm 3 /g).The significantly small particle sizes and high capacity of gas sorption are considered advantageous for envisaged application in practical industrial process.     

Voltammetric Determination of Captopril on a Glassy Carbon Electrode Modified with Copper Metal‐organic Framework

We report in this work, a new method for the determination of captopril by differential pulse voltammetry using a glassy carbon electrode modified with a copper metal‐organic framework (H‐Kust‐1 or Cu₃(BTC)₂ or Cu‐BTC), immobilized on the surface by a copolymer of acrylamide and sodium acrylate. This compound is detected by the formation of a copper(II)‐captopril complex that is observed in an oxidation potential at ca. +0.28 V vs . Ag/AgCl. A linear dynamic range is obtained for a captopril concentration of 0.5 μM to 7.0 μM and the voltammetric response is highly reproducible within 3.52 % error. The sensitivity of 9.71±0.37 nA μM⁻¹ and the limit of detection of 0.20±0.01 μM make this methodology highly applicable for practical applications. The determination of captopril in a commercial pharmaceutical sample showed a recovery of 93.3 %.     

Ethylene Epoxidation with Nitrous Oxide over Fe–BTC Metal–Organic Frameworks: A DFT Study

The epoxidation of ethylene with N₂O over the metal‐organic framework Fe–BTC (BTC=1,3,5‐benzentricarboxylate) is investigated by means of density functional calculations. Two reaction paths for the production of ethylene oxide or acetaldehyde are systematically considered in order to assess the efficiency of Fe–BTC for the selective formation of ethylene oxide. The reaction starts with the decomposition of N₂O to form an active surface oxygen atom on the Fe site of Fe–BTC, which subsequently reacts with an ethylene molecule to form an ethyleneoxy intermediate. This intermediate can then be selectively transformed either by 1,2‐hydride shift into the undesired product acetaldehyde or into the desired product ethylene oxide by way of ring closure of the intermediate. The production of ethylene oxide requires an activation energy of 5.1 kcal mol^?1, which is only about one‐third of the activation energy of acetaldehyde formation (14.3 kcal mol^?1). The predicted reaction rate constants for the formation of ethylene oxide in the relevant temperature range are approximately 2–4 orders of magnitude higher than those for acetaldehyde. Altogether, the results suggest that Fe–BTC is a good candidate catalyst for the epoxidation of ethylene by molecular N₂O.     

The Role of Multiwall Carbon Nanotubes in Cu‐BTC Metal‐Organic Frameworks for CO2 Adsorption

The discovery of natural gas fields with a high content of CO₂ in world gas reservoirs poses new challenges for CO₂ capture. This work investigates the use of the metal‐organic framework (MOF) Cu‐BTC and hybrid MWCNTs@Cu‐BTC for CO₂ adsorption. Cu‐BTC and hybrid MWCNTs@Cu‐BTC were synthesized by the solvothermal method. The results of imaging of intact MOF pores in Cu‐BTC and hybrid MWCNTs@Cu‐BTC nanocrystals by high‐resolution transmission electron microscopy (HRTEM) under liquid nitrogen conditions are presented. Physical characterizations of the solid adsorbents were made by using a selection of different techniques, including field‐emission scanning electron microscopy (FESEM), X‐ray powder diffraction (XRD), Fourier transform infrared (FT‐IR) spectroscopy, thermogravimetric analysis (TGA), Brunauer–Emmet–Teller (BET) surface area, and CO₂ adsorption and physisorption measurements. HRTEM and FESEM confirmed that Cu‐BTC has an octahedral shape and that the surface morphology of Cu‐BTC changes by the intercalation of MWCTNs. The results show that the modified Cu‐BTC improved the CO₂ adsorption compared to pure Cu‐BTC. The increase in the CO₂ uptake capabilities of hybrid MWCNTs@Cu‐BTC was ascribed to the intercalation of MWCNTs with Cu‐BTC crystals. The CO₂ sorption capacities of Cu‐BTC and hybrid MWCNTs@Cu‐BTC were found to increase from 1.91701 to 3.25642 mmol/g at ambient conditions.     

Zn3(BTC)2 as a Highly Efficient Reusable Catalyst for the Synthesis of 2‐Aryl‐1H‐Benzimidazole

Zn₃(BTC)₂ metal‐organic frameworks as recyclable and heterogeneous catalysts were effectively used to catalyze the synthesis of benzimidazole derivatives from o‐phenylendiamine and aldehydes in ethanol. This method provides 2‐aryl‐1H‐benzimidazoles in good to excellent yields with little catalyst loading. The catalyst was characterized using different techniques such as X‐ray diffraction (XRD), energy dispersive X‐ray (EDX) analysis, scanning electron microscopy (SEM), and Fourier transform infrared (FT‐IR) spectroscopy.     

A novel block turbo code for high-speed long-haul DWDM optical communication systems

A novel super forward error correction (SFEC) coding scheme, based on the block turbo code (BTC) of Bose–Chaudhuri–Hocguenghem (BCH)(64,57)×BCH(64,57), in high-speed long-haul dense wavelength division multiplexing (DWDM) optical communication systems is proposed. The simulation results and its analyses show that the net coding gain (NCG) of the novel SFEC code at iteration 6 is, respectively, 0.31 and 0.34 dB more than those of the BCH(3860, 3824)+BCH(2040, 1930) code and Reed–Solomon (RS)(255,239)+convolutional–self-orthogonal code (CSOC)(k₀/n₀=6/7, J=8) code in the Recommendation of ITU-T G.975.1 at iteration 3 for the bit error rate (BER) of 10⁻¹². The performance analyses for the novel SFEC code show that it has excellent advantages such as the shorter component code and rapid encoding/decoding speed; thus, both the complexity to implement its software/hardware and the delay time for its encoding/decoding can be greatly reduced. As a result, the novel SFEC coding scheme can better be applicable in high-speed long-haul DWDM optical communication systems. In addition, the design and implementation of the novel BTC are also analyzed and probed.     

氨基修饰的金属有机框架Cu_3(BTC)_2的制备及其CO_2吸附性能研究

首先制备了嫁接氨基的均苯三甲酸,同时以其为原料通过溶剂热法合成了金属有机框架材料Cu_3(NH_2BTC)_2,利用XRD、N_2吸附-脱附、热重、红外、原位红外分析等表征手段对吸附剂进行了表征,并通过固定床测量穿透曲线的方法研究其CO_2吸附性能。结果表明,氨基被成功引入Cu_3(BTC)_2骨架中。氨基修饰的Cu_3(BTC)_2对CO_2有着较高的吸附容量,在10 kPa,50℃的条件下CO_2吸附量为1.41 mmol/g,这源于材料对于CO_2同时存在着物理吸附和化学吸附。