摘要：
CeO2 and Sc2O3 co-stabilized ZrO2 ceramics have attracted much attention as potential thermal barrier coatings (TBCs) materials for applications above 1300 degrees C. In this study, a series of Sc0.04CexZr0.96-xO1.98 (SCZ, x = 0.08, 0.10, 0.12, 0.16) ceramic materials were synthesized with the solid-state method and their phase stability, microstructures and thermo-physical properties were systemically investigated by x-ray diffraction (XRD), Raman spectra, field emission scanning electron microscopy (SEM), thermal dilatometer, laser flash apparatus (LFA), and Vickers hardness tester. The results showed that Sc0.04Ce0.12Zr0.84O1.98 (4S12CZ) and Sc0.04Ce0.16Zr0.80O1.98 (4S16CZ) ceramic materials still maintained stable tetragonal phase structure after 100 h high temperature treatment at 1500 degrees C. SCZ had a high thermal expansion coefficient (TEC), low thermal conductivity, and high fracture toughness. The TEC of the ceramics increased with CeO2 addition because lattice energy reduced with increasing substitution of Zr4+ by bigger Ce4+ while thermal conductivity decreased due to the increase of lattice distortion. Compared with 4S12CZ, 4S16CZ exhibited a higher fracture toughness of 6.48 +/- 0.04 MPa m(1/2) and showed the better anti-sintering property. Besides, the thermal conductivity, TEC and thermal cycling lifetime of 4S16CZ were optimal. The comprehensive performance of 4S16CZ suggested it could be explored as a promising TBC material for high-temperature application.
期刊：
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY,2021年253:119561 ISSN：1386-1425
通讯作者：
Biao Gu<&wdkj&>Youming Shen
作者机构：
[Shen, Youming; Liu, Qingheng; Zhang, Chunxiang] Hunan Univ Arts & Sci, Prov Engn Res Ctr Electroplating Wastewater Reuse, Hunan Prov Cooperat Innovat Ctr Construct & Dev D, Coll Chem & Mat Engn,Hunan Prov Key Lab Water Tre, Changde 415000, Peoples R China.;[Liu, Mengqin; Gu, Biao; Han, Lujiao] Hengyang Normal Univ, Coll Chem & Mat Sci, Key Lab Funct Organometall Mat Coll Hunan Prov, Hengyang 421008, Peoples R China.
通讯机构：
[Biao Gu] K;[Youming Shen] P;Key Laboratory of Functional Organometallic Materials of College of Hunan Province, College of Chemistry and Materials Science, Hengyang Normal University, Hengyang 421008, PR China<&wdkj&>Province Engineering Research Center of Electroplating Wastewater Reuse Technology, Hunan Province Cooperative Innovation Center for the Construction & Development of Dongting Lake Ecological Economic Zone, Hunan Provincial Key Laboratory of Water Treatment Functional Materials, College of Chemistry and Materials Engineering, Hunan University of Arts and Science, Changde 415000, PR China
摘要：
Bisulfite (HSO3-) and sulfite (SO32-) are involved in numerous physiological processes of living systems. However, high levels of these substances are often correlated to many diseases. Herein, we designed and synthesized a simple full water-soluble colorimetric and far-red fluorescent probe (E)-1-methyl-4-(2-(1-methylquinolin-1-ium-3-yl)vinyl)quinolin-1-ium iodide trifluoromethanesulfonate (DQ) for HSO3-/SO32- detection by coupling 1,4-dimethylquinolinium with 3-quinolinium carboxaldehyde for the first time. The probe DQ showed high selectivity for HSO3- detection via a 1,4-nucleophilic addition reaction with distinct color changes from colorless to purple-red and remarkable far-red fluorescence enhancement in pure aqueous solutions. Specifically, the probe displayed a fast response (<15 s) for bisulfite, which renders it suitable for real time detection of HSO3-. Under the optimized conditions, the far-red fluorescence intensity was linear to the concentrations of HSO3- in the range from 0 to 25 mu M and the detection limit was as low as 0.11 mu M. Additionally, the probe could be applied to sense HSO3- on paper strips, real sample including vermicelli and sugar and image HSO3- in living cells, which indicated that probe DQ has potential application in food samples and living systems. (C) 2021 Elsevier B.V. All rights reserved.
期刊：
Journal of Food Composition and Analysis,2021年96:103708 ISSN：0889-1575
通讯作者：
He, Quanguo;Deng, Peihong
作者机构：
[Li, Guangli; He, Quanguo; Tian, Yaling; Wu, Yiyong; Xiao, Jinyun; Liu, Jun; Feng, Jinxia] Hunan Univ Technol, Sch Life Sci & Chem, Zhuzhou 412007, Peoples R China.;[Tian, Yaling; Deng, Peihong; Wu, Yiyong; Li, Junhua; Xiao, Jinyun; Feng, Jinxia] Hengyang Normal Univ, Dept Chem & Mat Sci, Key Lab Funct Organometall Mat Hunan Prov Univ, Key Lab Funct Metal Organ Cpds Hunan Prov, Hengyang 421008, Peoples R China.
通讯机构：
[He, Quanguo; Deng, Peihong] H;Hunan Univ Technol, Sch Life Sci & Chem, Zhuzhou 412007, Peoples R China.;Hengyang Normal Univ, Dept Chem & Mat Sci, Key Lab Funct Organometall Mat Hunan Prov Univ, Key Lab Funct Metal Organ Cpds Hunan Prov, Hengyang 421008, Peoples R China.
关键词：
Oxygen-functionalized multi-walled carbon nanotubes;Tyrosine;Acetylene black paste electrode;Voltammetric determination
摘要：
In this paper, acetylene black paste electrode (ABPE) was prepared and modified by oxygen-functionalized multi walled carbon nanotubes (MWCNT-COOH). The fabricated MWCNT-COOH/ABPE was further used for the investigation on the electrochemical behavior of tyrosine by cyclic voltammetry and second-order derivative linear sweep voltammetry. In 0.1 M pH 2.6 phosphate buffer solution, a well-defined anodic peak appeared at 924 mV, which was attributed to the electrooxidation of tyrosine on the modified electrode. The electrochemical parameters of tyrosine on the modified electrode were calculated. Under the optimal conditions, the oxidation peak current of tyrosine varies linearly with its concentration in the range of 0.04-1.0 mu M, 1.0-60 mu M and 60-600 mu M, and the detection limit is 0.02 mu M. The MWCNT-COOH/ABPE was applied to the determination of tyrosine in food with satisfactory results.
摘要：
Two Th (IV) complexes {[4-NO2-C6H4(O)C= N-N = C(R)-(R)C= N-N = C(O)-(4-NO2-C6H4)](2)Th(CH3OH)(2)} ( R = Ph ( I ); CH3 (II))were synthesized and characterized by IR, elemental analysis and thermal stability analysis, and the crystal structures were determined by X-ray diffraction. The Th in the complexes I and II adopt ten coordination configuration. Complex I and II also forms a two-dimensional network structure through the abundant hydrogen bond interaction of C -H on the benzene ring with O atom on NO2- groups. The UV-vis and quantum chemical calculations of I and II have been investigated. (c) 2021 Elsevier B.V. All rights reserved.
摘要：
Two new bearing Bi（Ⅲ） supramolecular compounds [Bi（pydcH）3(Bi（pydcH）（pydcH2）（pydc）(Bi（pydcH）（pydcH2）（pydc）]（1） and {[Bi（pydcH）3]·（H2O）5（Dmap）}2（2） have been successfully synthesized via hydrothermal reaction（pydcH2 = 2,6-pyridine dicarboxylate, Dmap = 4-dimethylamiopyridine）. They have been structurally determined by single-crystal X-ray analysis, and characterized by fluorescence analysis and thermogravimetric analysis（TG）. Both compounds 1 and 2 are of the same triclinic system with different structures. The decomposition mechanisms of compounds 1 and 2 are discussed. Compared to 1, lots of small molecules were possibly removed from compound 2 below 250 ℃. In addition, the photoluminescence properties were also investigated.
作者机构：
[Deng, Peihong; Li, Junhua] Hengyang Normal Univ, Key Lab Funct Organometall Mat Hunan Prov Univ, Dept Chem & Mat Sci, Key Lab Funct Met Organ Cpds Hunan Prov, Hengyang 421008, Peoples R China.;[He, Quanguo; Tian, Yaling; Wu, Yiyong; Xiao, Jingyun; Feng, Jinxia] Hunan Univ Technol, Sch Life Sci & Chem, Zhuzhou 412007, Peoples R China.
通讯机构：
[Peihong Deng] D;[Quanguo He] S;School of Life Science and Chemistry, Hunan University of Technology, Zhuzhou 412007, China<&wdkj&>Department of Chemistry and Material Science, Hengyang Normal University, Key Laboratory of Functional Metal-Organic Compounds of Hunan Province, Key Laboratory of Functional Organometallic Materials of Hunan Provincial Universities, Hengyang 421008, China
摘要：
In recent years, small-sized electrodes have drawn widespread attraction in electroanalysis due to high sensitivity, rapid response and low cost. Hereby, a sub-millimeter paste electrode with inner diameter of 0.8 mm was prepared by combining the excellent properties of reduced graphene oxide (rGO) and acetylene black (AB), and the electrochemical behavior of tyrosine (Tyr) on the modified electrode (denoted as rGO/ABPE) was investigated in detail. The electrochemical responses obtained on the sub-millimeter rGO/ABPE were compared with that obtained on a conventional size electrode with diameter of 3 mm. The results showed that the 0.8 mm one has better performance than that of 3 mm. Compared with the paste electrode made of graphite powder, the oxidation peak current of Tyr increased significantly due to the synergistic effect of rGO and AB. Under the optimized experimental conditions, the calibration curve of Tyr showed a linear relationship between 0.1 and 100 ?M (R = 0.9995) with good sensitivity of 3.314 ?A ?M-1 cm-2, and the detection limit was 0.06 ?M. By comparison with conventional size electrode, the detection of Tyr on the sub-millimeter electrode shows higher sensitivity, wider linear range and lower detection limit. In addition, the excellent reproducibility, stability and selectivity of the sub-millimeter rGO/ABPE make it suitable for Tyr analysis in both food and biological samples.
期刊：
JOURNAL OF THE ELECTROCHEMICAL SOCIETY,2021年168(12):126529 ISSN：0013-4651
通讯作者：
Deng, Peihong
作者机构：
[He, Quanguo; Deng, Peihong; Li, Junhua] Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.;[He, Quanguo; Deng, Peihong; Li, Junhua] Univ Hunan Prov, Key Lab Funct Organomet Mat, Hengyang 421008, Peoples R China.;[He, Quanguo; Deng, Peihong; Li, Junhua] Key Lab Funct Metal Organ Cpds Hunan Province, Hengyang 421008, Peoples R China.;[He, Quanguo; Deng, Peihong; Li, Junhua] Key Lab Chem Sensing & Catalysis, Hengyang 421008, Peoples R China.;[He, Quanguo; Zuo, Jinsong; Wei, Yanping; Feng, Jinxia; Xiao, Jingyun; Ding, Jianhua] Hunan Univ Technol, Sch Life Sci & Chem, Zhuzhou 412007, Peoples R China.
通讯机构：
[Deng, Peihong] H;[Deng, Peihong] U;[Deng, Peihong] K;Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.;Univ Hunan Prov, Key Lab Funct Organomet Mat, Hengyang 421008, Peoples R China.
摘要：
High levels of uric acid (UA) in the human body usually cause diabetes, hypertension and atherosclerosis, kidney diseases, and neurological diseases. Hence, it is important to develop sensitive methods for UA determination. In this paper, nanocomposite composed of ceria nanoparticles and reduced graphene was successfully modified on the surface of glassy carbon electrode (ceria NPs-rGO/GCE) by a simple electroreduction method. The morphology, structure and property of the ceria NPs-rGO/GCE was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The electrocatalytic activity of the ceria NPs-rGO/GCE for uric acid (UA) oxidation was studied in detail. The results showed that the ceria NPs-rGO/GCE exhibited excellent selectivity and high sensitivity for UA detection. In 0.05 M H2SO4 solution, a linear range of 0.02-20 mu M and a low detection limit of 8.0 nM of UA were obtained on the ceria NPs-rGO/GCE. This developed method was successfully applied for the detection of UA in human serum and urine samples, and its recoveries reached 95.8%-105.0%. (C) 2021 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.
期刊：
Microporous and Mesoporous Materials,2021年323:111240 ISSN：1387-1811
通讯作者：
Xia Xiaohong
作者机构：
[Deping, Wang] Hengyang Normal Univ, Coll Chem & Mat Sci, Hengyang 421008, Hunan, Peoples R China.;[Deping, Wang] Key Lab Funct Met Organ Cpds Hunan Prov, Hengyang, Peoples R China.;[Hongbo, Liu; Wufeng, Fan; Wenming, Hu; Xiaohong, Xia] Hunan Univ, Coll Mat Sci & Engn, Changsha 410082, Hunan, Peoples R China.;[Junqiang, Liu] Hunan Univ, Hunan Joint Int Lab Adv Mat & Technol Clean Energ, Changsha 410082, Hunan, Peoples R China.;[Hongbo, Liu] Chenzhou Shanshan Corp, Chenzhou 423400, Hunan, Peoples R China.
通讯机构：
[Xia Xiaohong] C;College of Material Science and Engineering, Hunan University, Changsha, Hunan, 410082, China<&wdkj&>Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy, Hunan University, Changsha, Hunan, 410082, China
摘要：
Metal-organic frameworks (MOFs) have attracted numerous attentions as anode materials for lithium-ion batteries (LIBs) owing to their unique tunable structures. However, utilizing MOFs in electrochemical devices has been hampered by the inferior electrical conductivity and poor stability that dominate the cycling stability and rate performance of electrodes. Herein, a Ni-PTA/graphene hybrid with porous spherical structure has been successfully constructed by interconnected needle-like Ni-MOFs nanocrystals after the introduction of amine functionalized graphene (NG). The conductivity and structural stability of the composites have been greatly improved due to the chemical bonds formed between the N-containing graphene and the MOFs. When used as anode materials for LIBs, the synthesized Ni-PTA/NG composite shows a superior Li storage with a reversible capacity of 1585 mAh g-1 at a current density of 200 mA g-1. In addition, Ni-PTA/NG composite demonstrates an ameliorative rate performance (340 mAh g-1 at 5 A g-1) and long-term cyclability (570 mAh g-1 at 1 A g-1 after 420 repeated cycles), significantly higher than traditional graphene/MOF composite materials. The novel method in this work paves a new way to form 3D structure by using NG to induce MOF germination, which may be extended to preparing other metal/metal oxides materials for electrochemical energy-storage systems.
作者机构：
[Yuan, Ze; Cui, Ying; Song, Minghui; Zhen, Deshuai; Hu, Jiawen] Hunan Univ, Hunan Key Lab Two Dimens Mat, Adv Catalyt Engn Res Ctr, Minist Educ, Changsha 410082, Hunan, Peoples R China.;[Yuan, Ze; Cui, Ying; Song, Minghui; Zhen, Deshuai; Hu, Jiawen] Hunan Univ, Coll Chem & Chem Engn, Changsha 410082, Hunan, Peoples R China.;[Cui, Ying; Li, Junhua] Hengyang Normal Univ, Coll Chem & Mat Sci, Hengyang 421001, Peoples R China.;[Zhu, Baode] Xiangnan Univ, Coll Chem Biol & Environm Engn, Chenzhou 423043, Peoples R China.;[Qian, Dong] Cent South Univ, Coll Chem & Chem Engn, Hunan Prov Key Lab Chem Power Resources, Changsha 410083, Peoples R China.
通讯机构：
[Zhen, Deshuai; Li, Junhua] H;[Zhu, Baode] X;Hunan Univ, Hunan Key Lab Two Dimens Mat, Adv Catalyt Engn Res Ctr, Minist Educ, Changsha 410082, Hunan, Peoples R China.;Hunan Univ, Coll Chem & Chem Engn, Changsha 410082, Hunan, Peoples R China.;Hengyang Normal Univ, Coll Chem & Mat Sci, Hengyang 421001, Peoples R China.
关键词：
Electrochemical biosensor;CRISPR-Cas13a system;Catalytic hairpin assembly;Cascade signal amplification;miRNA-21
摘要：
MicroRNAs (miRNAs) are related to many biological processes and regarded as biomarkers of disease. Rapid, sensitive, and specific methods for miRNA assay are very important for early disease diagnostic and therapy. In the present work, an ultrasensitive electrochemical biosensing platform has been developed for miRNA-21 assay by combining CRISPR-Cas13a system and catalytic hairpin assembly (CHA). In the presence of miRNA-21, it would hybridize with the spacer region of Cas13a/crRNA duplex to activate the cleavage activity of CRISPR-Cas13a system, leading to the release of initiator of CHA to generate amplified electrochemical signals. Base on the CRISPR-Cas13a-mediated cascade signal amplification strategy, the developed electrochemical biosensing platform exhibited high sensitivity with a low detection limit of 2.6 fM (S/N = 3), indicating that the platform has great potential for application in early clinical diagnostic.
作者机构：
[Fan, Shanji; Hu, Zecheng; Chen, Hong; Huang, Hong; Xu, Jiachi] Univ South China, Affiliated Hosp 1, Hengyang Med Sch, Hengyang 421001, Hunan, Peoples R China.;[Cui, Ying] Hengyang Normal Univ, Coll Chem & Mat Sci, Hengyang 421001, Peoples R China.
通讯机构：
[Cui, Ying] H;Hengyang Normal Univ, Coll Chem & Mat Sci, Hengyang 421001, Peoples R China.
关键词：
TiO2 Nanotubes;Cytochrome c;Sensitivity;CdS
摘要：
A CdS nanocrystal enhanced TiO2 nanotubes (CdS@TiO2 NATs) photoelectrode was prepared via successive ionic layer adsorption and reaction (SILAR) of CdS on the surface of TiO2 NATs. A HS-aptamer owing a specific binding toward cytochrome c was modified onto the CdS@TiO2 NATs, which resulting a decrease in the photoelectrical current intensity. Cytochrome c is therefore quantified based on the decrease in photoelectrical current. High specificity and high sensitivity were obtained with a linear range from 3 pM to 80 nM, and a limit of detection of 2.53 pM.
摘要：
A electrochemical sensor based on graphene and gold nanoparticles modified glassy carbon electrode (GCE) was developed for the determination of tyrosine (Tyr). The graphene and gold nanoparticles modified glassy carbon electrode (GR/Au NPs/GCE) was prepared by potentiostatic deposition of gold nanoparticles on the grephene coated GCE. Cyclic voltammetry and linear sweep voltammetry were used to study the electrochemical behavior of Tyr on the modified electrode, which showed improved electrocatalytic behavior for oxidation of Tyr due to the significant enhancement of peak current. A linear response between the peak current and the Tyr concentration was detected between 100 nM–100 μM and the detection limit (S/N = 3) was 47 nM. The simple preparation and the good sensitivity make this graphene/gold nanoparticles modified GCE very promising for Tyr analysis in real samples.
摘要：
More and more attention has been paid to AlCrN coatings with self-lubricating property and high temperature oxidation resistance. In this study, the synergy of V and Si on the microstructure, tribological and oxidation properties of AlCrN coatings is investigated in detail. With V is gradually replaced by Si, coatings' microstructures are transformed from compact columnar to coarse columnar, and a dense fine-grained structure, and finally to a featureless dense structure. When the V content is 10 at.%, the coating is consisted of c-VN and c-Al(Cr)N solid solution phases. As decreasing the ratio of V to Si, there is only a cubic Al-Cr-V-N solid solution phase in Al0.58Cr0.31V0.08Si0.03N coating and the coexistence of c-Al(Cr)N and h-Al(Cr)N phases in Al0.58Cr0.31V0.04Si0.07N coating. The addition of Si can promote the transition from c-Al(Cr)N solid solution to h-Al(Cr)N solid solution, and finally forming a nanocomposite structure composed of h-Al(Cr)N nanocrystalline and alpha-Si3N4 for Al0.58Cr0.32Si0.1N coating. The performance test results indicate that the Al0.58Cr0.31V0.04Si0.07N coating has the best resistance to plastic deformation, the lowest wear rate of 2.72 x 10(-16) m(3).N-1.m(-1) and the oxidation resistance temperature of 1000 degrees C attributing to the synergistic effect of V and Si.
摘要：
Rational design and construction of self-supporting electrodes with high energy exporting densities promise a future of wearable and portable devices. Herein, we demonstrate that, for the first time, a one-pot hydrothermal method for the in-site growth of Co3S4 -Ni3S2 on nickel foam (NF) with the assistance of a chelating agent sodium 5-sulfosalicylate (SSS) (labeled as CS4-Ni3S2@F-SSS) for high-performance super capacitors. Served directly as a self-supporting supercapacitor electrode, CS4-Ni3S2@F-SSS owns a specific capacitance of up to 2825.5 mF cm-2 at a corresponding 2 mA cm(-2) current density and a commendable rate capability of 82% conducted within a current density domain of 2 - 40 mA cm(-2) accompanied by good cyclability. More strikingly, the assembled tow-electrode (CS4-Ni3S2@F-SSS vs. active carbon (AC)@NF) all solid-state asymmetric supercapacitor (ASC) is capable of reaching an energy density of 40.9 Wh kg(-1) at a high power density of 1566.4 W kg(-1) with excellent durability (92.8% retention after 2000 charge-discharge cycles at 8 mA cm(-2)), which are amongst the top of analogous ASCs in peer reports. Additionally, the possible factors that are accountable for the extraordinary supercapacitive performance of CS4-Ni3S2@F-SSS are discussed and analyzed. (C) 2021 Elsevier B.V. All rights reserved.
期刊：
Journal of Hazardous Materials,2021年416 ISSN：0304-3894
作者机构：
[Dai, Cong] Hengyang Normal Univ, Coll Chem & Mat Sci, Hengyang 421001, Peoples R China.;[Dai, Cong] Hunan Engn Res Ctr Monitoring & Treatment Heavy M, Hengyang 421001, Peoples R China.;[Qian, Hai-Long; Yan, Xiu-Ping] Jiangnan Univ, State Key Lab Food Sci & Technol, Wuxi 214122, Jiangsu, Peoples R China.;[Qian, Hai-Long; Yan, Xiu-Ping] Jiangnan Univ, Sch Food Sci & Technol, Inst Analyt Food Safety, Wuxi 214122, Jiangsu, Peoples R China.;[Qian, Hai-Long; Yan, Xiu-Ping] Jiangnan Univ, Sch Chem & Mat Engn, Minist Educ, Key Lab Synthet & Biol Colloids, Wuxi 214122, Jiangsu, Peoples R China.
关键词：
Facile preparation;Nano porous organic cages;Fluorescence sensing;Copper ion
摘要：
Facile synthesis of nano porous organic cages with small size and good fluorescence property is highly desirable, but still challenging and scarce for their sensing applications. Here we report a rapid room-temperature recrystallization method for the preparation of nano porous organic cages with ultra-small size as a fluorescent probe for copper ion. The prepared nano porous organic cages gave the diameter of 2.49 +/- 0.04 nm, and exhibited stable emission at 535 nm with absolute quantum yield of 0.68%. On the basis of the coordination interaction and charge transfer between the nano porous organic cages and copper ion, a simple fluorescent probe for copper ion in aqueous solution was developed. The developed method gave a calibration function of QE = 0.4815lg[Cu2+] + 0.5847 (where QE is the quenching efficiency; [Cu2+] in mu M) (R2 = 0.9987) in a concentration range of 0.1-2 mu M, the limit of detection (3s) of 8 nM, and the relative standard deviation of 0.36% for 10 replicate determinations of 0.5 mu M copper ion. The recoveries of spiked copper ion in tap water samples ranged from 96.8% to 103.0%. The proposed method possesses good sensitivity, selectivity and accuracy.
摘要：
A method with high sensitivity, good accuracy and fast response is of ever increasing importance for the simultaneous detection of AA, DA and UA. In this paper, a simple and sensitive electrochemical sensor, which based on the polyvinylpyrrolidone (PVP)-graphene composite film modified glassy carbon electrode (PVP-GR/GCE), was presented for detecting ascorbic acid (AA), dopamine (DA) and uric acid (UA) simultaneously. The PVP-GR/GCE has excellent electrocatalytic activity for the oxidation of AA, DA and UA. The second-order derivative linear sweep voltammetry was used for the electrochemical measurements. The peak potential differences of DA-AA, DA-UA, and UA-AA (measured on the PVP-GR/GCE) were 212, 130 and 342 mV respectively. Besides, the over potential of AA, DA and UA reduced obviously, so did the peak current increase. Under the optimum conditions, the linear ranges of AA, DA and UA were 4.0 μM–1.0 mM, 0.02–100 μM, and 0.04–100 μM, respectively. The detection limits were 0.8 μM, 0.002 μM and 0.02 μM for AA, DA, and UA. The electrochemical sensor presented the advantages of high sensitivity and selectivity, excellent reproducibility and long-term stability. Furthermore, the sensor was successfully applied to the analysis of real samples.
摘要：
A new Cd-MOF containing the nucleobase adenine and multicarboxylates, Cd-2(tdc)(2)(1H-ade)(2)(H2O) (H(2)tdc = 2,5-thiophene carboxylic acid, 1H-ade = adenine), was synthesized successfully under hydrothermal condition and characterized by single-crystal X-ray diffraction, infrared spectrum, thermogravimetric analysis and photoluminescence. The two crystallographically unsymmetrical Cd atoms are bridged by 2,5-tdc ligands with (kappa(1)-kappa(1))-(kappa(1))-mu(3) and (kappa(1)-kappa(1))-mu(2) modes into two dimensional extended layers, which are further pillared with the neutral ade molecules to form a 3D frameworks stabilized by extensive pi center dot center dot center dot pi interactions between imidazole-, pyrimidine- and thiophene-rings. Inspection of the structure reveals that the architecture can be simplified as a 3,4,5- connected networks with a Schlafli symbol of (6(2)center dot 8)(4(2)center dot 6(3)center dot 8)(4(2)center dot 6(5)center dot 8(3)). The photochemical property shows that the luminescent emission can be significantly quenched by aromatic azo compounds. The quenching effect coefficient (K-sv) for bis(4-imidazol-1-yl-phenyl)diazene is determined to be 4.1 x 10(4) m(-1), indicating the title compound as a potential fluorescent sensing materials.
摘要：
Here, we report a nano-sized red phosphorous/biomass-derived porous carbon (P@BDPC) which is employed as anode materials for lithium ion batteries (LIBs) via a facile vaporization-condensation-conversion strategy (VCC) with tobacco stem as the carbon precursor. The biomass-derived porous carbon not only acts as the host of red phosphorus to enhance the electrical conductivity, but also minimizes the volume expansion (approximate to 400%) during cycling. The obtained P@BDPC composite with a high red phosphorus content (62.1 wt%) delivers a high specific capacity of 1689 mA h g(-1) at 500 mA g(-1) with an initial Coulombic efficiency (ICE) of 91.7% and superior rate capability of 599 mA h g(-1 )at 30 A g(-1). Furthermore, a high reversible capacity of 918 mA h g(-1) can be retained over 600 cycles at 5 A g(-1), indicating a remarkable cycle stability. More importantly, the introduction of agriculture waste-tobacco stem contributes to building low-cost, high-performance anode materials.
