固态氢分子基质隔离高分辨光谱实验装置及其应用

建立了用傅立叶变换红外光谱和中红外差频激光光谱方法研究氢基质隔离光谱的测量装置. 作为装置的测试, 观测了3 cm长的固态氢分子晶体在1-5 μm波段的吸收光谱. 并用中红外差频激光测量其在2410 cm-1附近的W0(0)(v=0→0, J=6→0)谱线的高分辨精细结构. 通过在低温基片上喷溅沉积氢分子晶体薄膜的方法, 对氢基质隔离的CO2分子的高分辨红外吸收光谱进行了研究.     

Analysis of Isomeric Alkylated Polycyclic Aromatic Hydrocarbons by Matrix Isolation Fourier Transform Infrared Spectroscopy

Abstract

Matrix isolation Fourier transform infrared spectra of isomeric methylnaphthalenes and methylbiphenyls, in N₂ matrices at 15 K, are compared with each other and with those of the respective parent hydrocarbons. The applicability of matrix isolation Fourier transform infrared spectroscopy to both identification and quantitative analysis of individual alkylated polycyclic aromatic hydrocarbon isomers in mixtures is demonstrated.     

Reactions of Group V Metal Atoms with Hydrogen Sulfide:Argon Matrix Infrared Spectra and Theoretical Calculations

The reaction of laser-ablated vanadium, niobium and tantalum atoms with hydrogen sulfide has been investigated using matrix isolation FTIR and theoretical calculations. The metal atoms inserted into the H-S bond of H₂S to form the HMSH molecules (M=V, Nb, Ta), which rearranged to H₂MS molecules on annealing for Nb and Ta. The HMSH molecule can also further react with another H₂S to form the H₂M(SH)₂ molecules. These new molecules were identified on the basis of the D₂S and H₂³⁴S isotopic substitutions. DFT (B3LYP and BPW91) theoretical calculations are used to predict energies, geometries, and vibrational frequencies for these novel metal dihydrido complexes and molecules. Reaction mechanism for formation of group V dihydrido complex was investigated by DFT internal reaction coordinate calculations. The dissociation of HVSH gave VS+H₂ on broad band irradiation and reverse reaction happened on annealing. Based on B3LYP calculation releasing hydrogen from HVSH is endothermic only by 13.5 kcal/mol with lower energy barrier of 16.9 kcal/mol.     

CNT/Fe-Ni/TiO_2/ZnO阵列修饰Ni阳极的制备及光催化制氢性能

采用层层自组装方法在Ni片阳极上构建TiO2/Zn O纳米棒阵列,以二氧化钛前驱体溶胶中掺杂的铁和镍为催化剂,通过气相沉积法在TiO2/Zn O纳米棒阵列间原位生长碳纳米管(CNTs),得到CNT/Fe-Ni/TiO2/Zn O复合光催化剂修饰的光活性Ni片阳极.以碱性电解池为基础,用紫外线辐照修饰的Ni阳极实现光催化和电解水的有机耦合制氢过程.通过场发射扫描电子显微镜(FESEM)、透射电子显微镜(TEM)、拉曼光谱(Raman)和电化学阻抗谱(EIS)对CNT/Fe-Ni/TiO2/Zn O复合膜光催化剂的结构进行了表征,并测试了其光催化辅助电解水制氢(WEAP)活性.结果表明,生长了碳纳米管的光催化复合膜CNT/Fe-Ni/TiO2/Zn O修饰的Ni阳极的产氢速率分别比Fe-Ni/TiO2/Zn O修饰的Ni阳极和纯Ni片提高了93.7%和533.0%.     

Matrix Isolation and Spectroscopic Characterization of the Phenylperoxy Radical and Its Rearranged Products

The phenylperoxy radical 1 has been synthesized by the reaction of the phenyl radical 2 with ³O₂. Radical 1 could be either generated in the gas phase and subsequently trapped in solid argon at 10 K, or directly synthesized in argon matrices. By reacting 2 as well as its perdeuterated isotopomer [D₅]‐ 2 with ¹⁶O₂ and with ¹⁸O₂, respectively, the four isotopomers [H₅]‐¹⁶O₂‐ 1 , [D₅]‐¹⁶O₂‐ 1 , [H₅]‐¹⁸O₂‐ 1 , and [D₅]‐¹⁸O₂‐ 1 were matrix‐isolated and characterized by IR spectroscopy. The experimental IR spectra are in excellent agreement with results from DFT calculations. Irradiation of 1 with visible light produces the 2‐oxepinoxy radical 5 in a clean reaction. Subsequent irradiation results in ring‐opening and formation of several conformers of ketoketene 6 . The radicals 1 , 5 , and 6 play an important role in the combustion of aromatic hydrocarbons and could now be isolated and spectroscopically characterized for the first time.     

和频与差频振动光谱实验构型的分析模拟

实验构型分析是定量分析和频振动光谱的基础.变换实验构型,不仅要考虑某一振动模式信号强度的大小,还要考虑不同构型下的信号检测效率.现有的和频振动光谱实验构型分析主要考虑前者.本文探讨实验构型分析中所涉及的信号检测效率问题,模拟在共向式和频(差频)及对射式和频(差频)振动光谱实验中选取何种实验构型对采集信号光更加合理有效.利用相干光学过程能量守恒和动量守恒原理,分析了入射角及入射光频率等因素对信号出射角的影响,并模拟了信号出射角与入射角及入射光频率的关系,得到了可选的入射角组合最多、出射角随入射光频率变化最小的实验构型.结果表明,和频振动光谱采取共向式实验构型,差频振动光谱采取对射式实验构型,有利于信号采集,进而有利于用实验构型分析方法对和频(差频)振动光谱进行定量研究.     

An Overview of Metal-Organic Framework Based Electrocatalysts: Design and Synthesis for Electrochemical Hydrogen Evolution,Oxygen Evolution,and Carbon Dioxide Reduction Reactions

Due to the increasing global energy demands, scarce fossil fuel supplies, and environmental issues, the pursued goals of energy technologies are being sustainable, more efficient, accessible, and produce near zero greenhouse gas emissions. Electrochemical water splitting is considered as a highly viable and eco-friendly energy technology. Further, electrochemical carbon dioxide (CO₂) reduction reaction (CO₂RR) is a cleaner strategy for CO₂ utilization and conversion to stable energy (fuels). One of the critical issues in these cleaner technologies is the development of efficient and economical electrocatalyst. Among various materials, metal-organic frameworks (MOFs) are becoming increasingly popular because of their structural tunability, such as pre- and post- synthetic modifications, flexibility in ligand design and its functional groups, and incorporation of different metal nodes, that allows for the design of suitable MOFs with desired quality required for each process. In this review, the design of MOF was discussed for specific process together with different synthetic methods and their effects on the MOF properties. The MOFs as electrocatalysts were highlighted with their performances from the aspects of hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and electrochemical CO₂RR. Finally, the challenges and opportunities in this field are discussed.     

12-磷钨酸及其铯盐的酸位可接近性:固体核磁共振探针分子研究

 固体酸催化剂的酸位可接近性是影响催化剂性能的重要性质. 使用与反应分子大小接近的碱性探针分子三甲基膦和固体核磁共振技术,定量研究了磷钨酸及其铯盐的酸位可接近性. 结果表明,磷钨酸具有“假液相性”,三甲基膦可以接近磷钨酸体相中的酸位,在无水的磷钨酸中,有大约2/5的酸位可以被三甲基膦所接近. 磷钨酸的铯盐没有“假液相性”,探针分子只能接近催化剂表面的酸位,在无水的Cs1.5H1.5PW12O40中,只有大约5%的酸位能够被三甲基膦所接近.     

辣根过氧化物酶生物传感器的制备及其应用于过氧化氢的测定

通过将碳纳米管及二氧化钛复合材料(CNT-TiO2)修饰于金电极表面,并借其对辣根过氧化物酶的静电吸附和对羧酸基的高反应特性,使辣根过氧化物酶(HRP)固定在CNT-TiO2表面,制成了辣根过氧化物酶生物传感器(HRP-CNT-TiO2)。对此修饰电极在磷酸盐缓冲介质(pH7.2)中的电催化性质及其电催化反应的最佳条件作了研究。试验结果表明,此电极对过氧化氢有很好的电催化特性,且发现当过氧化氢的浓度在4.2×10-7~3.2×10-4mol.L-1之间与ΔI之间呈线性关系,检出限(S/N=3)为7.2×10-8mol.L-1。为试验方法的精密度,对过氧化氢的浓度水平为5×10-5mol.L-1的条件下进行了8次测定,结果的RSD值为4.5%。     

Non-invasive Monitoring of Biochemical Response of Wheat Seedlings Toward Titanium Dioxide Nanoparticles Treatment Using Attenuated Total Reflectance Fourier Transform Infrared and Laser Induced Fluorescence Spectroscopy

Widespread commercial application of titanium dioxide nanoparticles leads to their dispersion in the environment and inevitable interaction with living organisms. Their presence necessitates the monitoring of nanoparticle interactions with plants using advanced techniques that are capable of noninvasively and sensitively estimating the changes involved in the biochemical profile. The current study aims to investigate the effects of titanium dioxide nanoparticles on biochemicals of wheat leaves using label free, nondestructive, rapid, sensitive, and advanced spectroscopic probes: laser induced fluorescence and attenuated total reflectance Fourier transform infrared spectroscopy coupled with multivariate analysis. The fluorescence and infrared spectra of control and titanium dioxide nanoparticle treated wheat leaves were acquired in the region from 400 to 800?nm and 4000 to 485?cm^?1. The treatment of titanium dioxide nanoparticles decreases the chlorophyll content and the concentrations of cellulose, hemicellulose, xyloglucans, pectin, and lignin indicating interferences in the biosynthesis and structure of cell walls of the wheat leaves. The level of amide I, carbonyl, and methylene groups also increases following the treatment of titanium dioxide nanoparticles indicating lipid and protein peroxidation and the accumulation of carbonyl compounds. The changes in the integrated area ratios of the amide II/amide I, carbonyl/methyl, and methylene/amide II bands demonstrate disorder in the membrane integrity. This study establishes the efficiency of noninvasive, label-free, and rapid protocols based on attenuated total reflectance Fourier transform infrared and laser induced fluorescence to monitor the interactions of nanoparticles with plants at early stage of plant growth before visual signs of toxicity appear.     

烟草近红外光谱分析网络化及其应用进展

该文回顾了近红外光谱(NIRS)分析技术的应用历程以及"近红外光谱分析+互联网"模式在烟草领域中的应用研究与实践,探讨了在近红外光谱分析网络化环境中,近红外光谱仪器设备存在的硬件差异以及常规化学计量学方法(算法)在建模、数据处理存在的不足对近红外光谱的深度应用产生的影响,并提出了近红外光谱分析云计算应用的解决思路。最后,对大数据时代近红外光谱分析网络化模式的应用前景进行了展望。     

HATR-FTIR-排序法识别中药材紫花地丁及其伪品的研究

采用水平衰减全反射傅里叶变换红外光谱(HATR-FTIR)法测定了紫花地丁及其伪品如白花地丁、犁头草、辽宁堇菜及匍伏堇的根木质部和茎外表皮部的傅里叶变换红外光谱,采用主成分分析法(PCA)比较了正伪品之间的差异程度。结果表明：基于傅里叶变换红外光谱的主成分分析在反映同科同属不同种植物化学组成差异程度上具有应用价值。     

Infrared Spectra of Protonated Coronene and Its Neutral Counterpart in Solid Parahydrogen: Implications for Unidentified Interstellar Infrared Emission Bands

Large protonated polycyclic aromatic hydrocarbons (H⁺PAHs) are possible carriers of unidentified infrared (UIR) emission bands from interstellar objects, but the characterization of infrared (IR) spectra of large H⁺PAHs in the laboratory is challenging. IR absorption spectra of protonated coronene (1‐C₂₄H₁₃⁺) and mono‐hydrogenated coronene (1‐C₂₄H₁₃^.), which were produced upon electron bombardment of parahydrogen containing a small proportion of coronene (C₂₄H₁₂) during matrix deposition, were recorded. The spectra are of a much higher resolution than those obtained by IR multiphoton dissociation by Dopfer and co‐workers. The IR spectra of protonated pyrene and coronene collectively appear to have the required chromophores for features of the UIR bands, and the spectral shifts on an increase in the number of benzenoid rings point in the correct direction towards the positions of the UIR bands. Larger protonated peri‐condensed PAHs might thus be key species among the carriers of UIR bands.     

Prussian Blue Modified Carbon Ionic Liquid Electrode: Electrochemical Characterization and Its Application for Hydrogen Peroxide and Glucose Measurements

Prussian blue modified carbon ionic liquid electrodes (PB‐CILEs) were fabricated using chemical and electrochemical procedures. Chemically fabricated PB‐CILE exhibited an excellent sensitivity (0.0866 μA μM^?1), low detection limit (0.01 μM) and two linear ranges (0.01–1 and 1–600 μM) toward hydrogen peroxide. Then, glucose oxidase (GOx) was immobilized on the surface of PB‐CILE to fabricate glucose biosensor using three different procedures involving cross linking with glutaraldehyde (GLU) and bovine serum albumin (BSA), entrapment into the Nafion matrix and covering with a sol‐gel layer. Glucose biosensor fabricated using cross linking procedure showed the best sensitivity (0.0019 μA μM^?1) and operational stability for glucose.     

用傅里叶变换红外光谱差减技术自动监测大气毒物的软件及应用

本文介绍了大气毒物傅里叶变换红外光谱自动差减定量软件，介绍了方法的原理和软件的结构与功能。该技术能够进行数据库的实时咨询，差减谱位的智能搜索和光谱自动差减定量，实现了大气毒物自动定量分析。运用于实际样品分析，快速准确，优于其它的傅里叶变换红外光谱定量技术。     

Fabrication and Application of a Sensitive and Highly Stable Copper Hexacyanoferrate Modified Carbon Ionic Liquid Paste Electrode for Hydrogen Peroxide and Glucose Detection

A three‐factor mixture design and response surface methodology were employed to find the optimal weight ratio of graphite powder, n‐dodecylpyridinium hexafluorophosphate and paraffin for the fabrication of a copper hexacyanoferrate modified carbon ionic liquid paste electrode (CuHCFe‐CILPE). The fabricated sensor showed electrocatalytic activity towards oxidation and reduction of hydrogen peroxide. It also was observed that the electrocatalytic activity for hydrogen peroxide oxidation was much higher than the electrocatalytic activity for hydrogen peroxide reduction. Glucose oxidase was then successfully immobilized on the surface of the proposed sensor to examine the possibility of using CuHCFe‐CILPE for the biosensor fabrication.     

Green Synthesis of Ag Nanoparticles by Callicarpa Maingayi: Characterization and Its Application with Graphene Oxide for Enzymeless Hydrogen Peroxide Detection

A facile green synthesis of silver nanoparticles (AgNPs) was achieved using aqueous leaf extract of Callicarpa Maingayi as a reducing and stabilizing agent during the synthesis from its salt solutions. The synthesized silver nanoparticles were analyzed with transmission electron microscopy (TEM), X‐ray diffraction (XRD) and energy dispersive spectrometer (EDS). XRD study shows that the particles are crystalline in nature with face centered cubic geometry. The crystallite size obtained from XRD is about 15 nm which is in agreement well with the TEM results. A new nanostructure sensor was constructed by immobilizing silver nanoparticles and graphene oxide (AgNPs‐GO) composite film on a glassy carbon electrode (AgNPs‐GO/GCE). It was found that the AgNPs‐GO composite exhibits good catalytic activity toward the reduction of hydrogen peroxide (H₂O₂), leading to an enzymeless sensor with a fast amperometric response time of less than 5 s, high selectivity, good reproducibility and stability. The linear range was 5.0 μM to 700 μM with a detection limit of 0.6 μM (S/N = 3).     

固体氧化物燃料电池阳极材料研究及其在高温水电解制氢方面的应用

本文综述了固体氧化物燃料电池阳极材料的研究现状和进展。详细地介绍了国内外固体氧化物燃料电池阳极材料的制备、改性、微观结构与性能关系以及阳极反应动力学机理,并对各种材料适用的条件和优缺点进行了比较。对阳极材料在高温电解制氢领域阴极上的应用前景进行了展望。