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双甘膦在纳米TiO2-CNT/Pt复合膜电极电催化氧化 总被引：1，自引：0，他引：1
通过溶胶-凝胶法在Ti表面修饰一层nanoTiO2/CNT复合膜和电化学扫描电沉积法制备在Ti基体上的纳米TiO2-碳纳米管复合膜载Pt（nanoTiO2-CNT/Pt）复合催化剂。透射电镜（TEM）和X射线衍射（XRD）结果表明,锐钛矿型纳米TiO2粒子和Pt纳米粒子（粒径均为5-10nm）均匀地分散在碳纳米管表面。通过循环伏安和电解合成法研究表明,常温常压下nanoTiO2-CNT/Pt复合膜电极对双甘膦的电化学氧化具有高催化活性和稳定性,复合催化剂对双甘膦的电氧化的高催化活性可归因于nanoTiO2、CNT和Pt纳米粒子的协同催化作用。 相似文献
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以电合成前驱体Ti(OEt)4直接水解法和电沉积法制备Ti基纳米TiO2-碳纳米管复合膜载P(tPt/nanoTiO2-CNT)复合电极。透射电镜(TEM)和X射线衍射(XRD)测试表明,锐钛矿型纳米TiO2粒子和Pt纳米粒子(粒径约8nm)均匀地分散在碳纳米管表面。通过循环伏安法研究Pt/nanoTiO2-CNT电极对Ce3+的电催化性能,Ce3+氧化峰电位约为1.27V(vs.SCE),比Pt/nanoTiO2电极负移30mV,峰电流约高45mA·cm-2。 相似文献
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用溶胶-凝胶法在Ti基表面修饰一层的TiO2膜和稀土Pr掺杂的TiO2膜,分别制得空白Ti/nanoTiO2膜电极和Ti/Pr2O3-nanoTiO2膜电极。XRD测试表明Ti/Pr2O3-nanoTiO2膜电极组分晶型为锐钛矿,颗粒粒径计算为15.8 nm。SEM测试形貌表明Ti/Pr2O3-nanoTiO2膜电极表面颗粒尺寸在10~15 nm之间,无团聚,颗粒均匀分布。循环伏安法探究了空白Ti/nanoTiO2膜电极和Ti/Pr2O3-nanoTiO2膜电极分别在无机相H2SO4溶液和有机相DMF溶液中电催化还原活性。结果表明:在两种溶液中,Ti/Pr2O3-nanoTiO2膜电极与空白Ti/nanoTiO2膜电极相比,电催化活性在无机和有机相中分别增强3.0倍和2.8倍,并且该方法制备的电极电催化稳定性高。 相似文献
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In this paper, 2,3,5-trimethyl-1,4-benzoquinone(TMBQ) was synthesized through the direct oxidation of1,2,4-trimethylbenzene(pseudocumene, TMB) in the HCOOH–H_2O_2 system. The influence ofthree active species was studied, including performic acid(PFA) generated in formic acid, peracetic acid(PAA) generated in acetic acid, and trifluoroperacetic(TFPA) acid generated in trifluoroacetic acid. The effects ofsulfuric acid and sodium formate addition were investigated, the overoxidation ofTMB was discussed, and the main reason for the decreasing selectivity was revealed. The oxidation ofTMB can be controlled and improved through adjusting the reaction temperature, mole ratio ofoxidant to substrate, and reactant concentration. The TMBQ yield of28% was achieved with a TMB concentration of0.2 mol/L, H_2O_2/TMB mole ratio of6:1, and reaction temperature 37 °C. The selectivity of72% was obtained with a TMB concentration of0.2 mol/L, H_2O_2/TMB mole ratio of5:1, and reaction temperature of27 °C. The reaction mechanisms were proposed and discussed based on the gas chromatography–flame ionization detection(GC–FID) and gas chromatography–mass spectrometer(GC–MS) results. 相似文献
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采用溶胶-凝胶法,以钛酸丁酯为原料制备Ti基TiO2膜电极,制得稀土La掺杂的Ti/La2O3-nanoTiO2膜电极。运用XRD,SEM,CV等方式对所制得的掺杂电极进行了表征,XRD测试结果表明Ti/La2O3-nanoTiO2膜电极组分晶型均为锐钛矿型,颗粒粒径约为20nm。 SEM形貌显示Ti/La2O3-nanoTiO2电极表面颗粒比较均匀,颗粒尺寸约在10~15 nm之间。通过循环伏安法研究了Ti/La2O3-nanoTiO2膜电极在无机相HCl溶液中以及有机相马来酸溶液中的电催化还原活性。结果表明：在两种溶液中,稀土离子掺杂改性后的Ti/La2O3-nanoTiO2膜电极与空白Ti/nanoTiO2膜电极相比,电催化活性明显增强,并且该方法制备的电极电催化稳定性高。 相似文献
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介绍了一种将TiO2光催化剂担载在新型载体上的光催化电极.新型载体是用炭质材料和聚四氟乙烯制备的,它具有电合成H2O2的功能.在电流密度为15 mA/cm2时,光催化电极不仅具有高达80%的电合成H2O2的电流效率,而且该电极的电位处在0.02 V(SCE)左右,使载体表面的TiO2光催化剂获得了约+0.47 V的阳极偏压(相对平带电势),对增加TiO2光催化反应效率十分有益.在具有新型光催化电极的光反应体系中,水中的有机分子受到来自溶液中大量·OH自由基(H2O2被紫外光分解的中间产物)的均相氧化(即光化学氧化),以及来自TiO2表面光生空穴的复相氧化(即光催化氧化).在光化学氧化和光催化氧化的联合作用下,有机分子的矿物化反应速度显著提高. 相似文献
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采用溶胶凝胶法制备了掺杂La-Nd混合元素的Ti/Sb-SnO2电极,掺杂比例为Sn∶Sb∶La∶Nd=100∶10∶5∶4(原子质量比),通过正交实验确定该电极处理酱油废水的最佳工艺条件:电流密度40mA/cm2,电解时间90 min,极板间距4.0cm,pH值为5,在此条件下电极对酱油废水COD和色度的去除率分别为34.3%和90.11%,达到了预处理要求。 相似文献
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在酯化催化剂（H2SO4）作用下．异丁醇在Pb-PbO2阳极上电解氧化直接合成异丁酸异丁酯．考察了电极、温度、通电量及异丁醇浓度对产率的影响。 相似文献
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在含有0.2 mol.L-1苯胺的0.5mol.L-1H2SO4溶液中,采用循环伏安法(CV),以扫描速度50mv.s-1,扫描电位为-0.1～0.9V,在碳纳米管/纳米TiO2(CNT/nanoTiO2)膜电极上实现了苯胺的电化学聚合,并通过扫描电镜对膜层的微观形貌进行观察,发现这种在纳米基体上聚合得到的聚苯胺膜呈疏松、多孔的纳米纤维网状结构,不同于在金属基体上聚合得到的颗粒状聚苯胺膜. 相似文献
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Hong-xia Che Bo Tian Li-na Bai Li-ming Cheng Li-li Liu Xiao-na Zhang Zhan-mei Jiang Xiao-xi Xu 《Journal of Zhejiang University. Science. B》2015,16(8):672-679
Traditional methods for detecting lactoperoxidase (LP) are complex and time-consuming, so a test strip was made based on the enzymatic reaction principle to enable quick and convenient detection of LP in raw milk. In this study 0.1 mol/L citric acid (CA)/0.2 mol/L disodium hydrogen phosphate (NaP) buffer solution (pH 5.0), 22 mmol/L 3,3'',5,5''-tetramethylbenzidine (TMB), 0.6 mmol/L hydrogen peroxide (H2O2), and 0.5% Tween-20 or 0.3% cetyltrimethyl ammonium bromide (CTAB) were optimal for preparing a quick, sensitive, and accurate LP test strip. The coefficient of variation (CV) of the estimated LP concentrations ranged from 2.47% to 6.72% and the minimum LP concentration detected by the test strip was 1–2 mg/L. Estimates of active LP in sixteen raw milk samples obtained using the test strip or the TMB method showed a good correlation (r=0.9776). So the test strip provides a quick, convenient, and accurate method for detecting the LP concentration of raw milk. 相似文献
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本文采用正交试验法对非均相电解Ce2（SO4）3条件进行摸索,得出非均相电解Ce2（SO4）3的最佳电解条件为：硫酸铈浓度0.45mol.L-1,硫酸浓度为1.5 mol.L-1,电流密度200 mA.cm-2,电解电量比为110%,电解温度为40℃。在最优条件下,五次平均电流效率达到96.00%。 相似文献
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采用熔体快淬-去合金化法制备多孔PtFe纳米材料,通过X射线衍射、扫描电子显微镜及高分辨透射电子显微镜对其结构进行了表征.并研究了其在H2O2和3,3’,5,5’-四甲基联苯胺(TMB)催化体系中作为过氧化物酶的催化活性.研究发现,此纳米酶对H2O2和TMB具有较好的亲和性能,该催化反应符合Michaelis-Menten动力学理论. 相似文献
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应用电化学法处理染料中间体生产排放的高盐度有机废水。考察了电极材料、电流密度、电解时间等因素对处理效果的影响。实验结果表明。该法能够有效地去除废水中的有机物，提高透明度，在电流密度0．015A／cm^2，槽电压8．4V，电解90min，CODcr和色度的去除率分别达到了65％和70％。本文亦对含盐染料配水进行了研究，对降解机理做了初步的探讨。 相似文献
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用固相反应法制备La（1-x）2／3Ca1／3MnO3（V-LCMO）和（La（0.7-x）Y0.3）2／3Ca1/3MnO3）（V-LY-CMO）（x〈0．15）系列的La空位锰氧化物样品。X射线衍射（XRD）测量分析表明所有的样品均为单相,具有正交对称性（Prima）。体系的晶构参数以及Mn-O键长和Mn-O-Mn键角随空位浓度不同而改变,表明局域Jahn-Teller效应的存在。输运测量表明,不同的空位及空位浓度影响磁电阻效应,在X=0．04时磁电阻值在转变温度‰处达到最大值约为220％,我们认为很大的磁电阻效应与Y部分替代La有关,是双交换作用与Jahn-Teller效应竞争的结果。 相似文献
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Ding Teng Sia David F. Treagust A. L. Chandrasegaran 《International Journal of Science and Mathematics Education》2012,10(6):1325-1345
This study was conducted with 330 Form 4 (grade 10) students (aged 15??C?16?years) who were involved in a course of instruction on electrolysis concepts. The main purposes of this study were (1) to assess high school chemistry students?? understanding of 19 major principles of electrolysis using a recently developed 2-tier multiple-choice diagnostic instrument, the Electrolysis Diagnostic Instrument (EDI), and (2) to assess students?? confidence levels in displaying their knowledge and understanding of these electrolysis concepts. Analysis of students?? responses to the EDI showed that they displayed very limited understanding of the electrolytic processes involving molten compounds and aqueous solutions of compounds, with a mean score of 6.82 (out of a possible maximum of 17). Students were found to possess content knowledge about several electrolysis processes but did not provide suitable explanations for the changes that had occurred, with less than 45?% of students displaying scientifically acceptable understandings about electrolysis. In addition, students displayed limited confidence about making the correct selections for the items; yet, in 16 of the 17 items, the percentage of students who were confident that they had selected the correct answer to an item was higher than the actual percentage of students who correctly answered the corresponding item. The findings suggest several implications for classroom instruction on the electrolysis topic that need to be addressed in order to facilitate better understanding by students of electrolysis concepts. 相似文献
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本实验研究了以不锈钢片单独做阳极和以活性碳纤维毡片（＋不锈钢）的复合阳极对TNT废水电解效果的影响,并对电解机理进行了初步的探讨。原废水的TNT浓度为70—90mg／L,COD约为290—340mg／L,PH为7．5—9。实验数据显示,当槽电压为10V,PH值为3,外加电解质Na2SO4lg／L,极板间距为4era,电流密度为15mA／em。,搅拌转速为260r／min,电解2h时,以活性碳纤维＋不锈钢复合材料为阳极处理原废水,对TNT和COD的降解率分别为66．6％和55．5％,然而单独以不锈钢材料为阳极情况下,对TNT和COD的降解率仅为43．5％和24．7％。结果表明以活性碳纤维＋不锈钢复合材料为阳极对TNT废水中的有机物的电解效果显著,对实际工程废水处理有一定的指导意义。 相似文献
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Damien Page 《School Leadership & Management》2014,34(3):269-283
This article presents findings from a study of five head teachers who were responsible for the management of serious teacher misbehaviour (TMB) in England. In cases that included the downloading of extreme pornography on a school laptop and a sexual relationship with a pupil, the multiple impacts of TMB were potentially devastating to the well-being of pupils, staff and the reputation of the schools. The article highlights a number of strategies for managing serious TMB considered best practice by the head teachers as well as discussing other, more nuanced issues that accompany such cases including trust relations, the influence of gender and the difficulty of simultaneous immersion and detachment required of head teachers to effectively manage such cases. 相似文献