电化学氧化处理难降解废水的研究进展

综述了国内外电化学氧化处理难降解废水的研究现状,详细阐述了电化学氧化机理,包括阳极氧化技术和阴极还原技术,介绍了影响电化学氧化降解效率的主要因素,包括电极材料、电化学反应器、溶液的pH值、溶剂体系以及其它因素.从有机污染物电化学氧化机理的研究、电极材料的研制、电板结构的研究和高效电解反应器的开发、对特定的电化学氧化系统...     

常见电镀液中络合剂的电化学阳极降解研究

主要介绍了电化学阳极氧化机理,讨论了直接电化学氧化和间接电化学氧化的氧化途径。重点综述了不同阳极材料,如碳电极、金属单质电极和尺寸稳定阳极对电镀液中络合剂催化降解性能的影响。最后提出了电化学氧化技术中阳极材料的研究趋势,寻找催化活性高、寿命长、成本低的阳极材料是电化学氧化技术处理污染物的主要研究方向。     

电催化氧化处理有机废水阳极材料的研究进展

水体中存在的微量有机污染物对人类及生物的正常生命活动构成了严重威胁,有效去除这些污染物已成为当务之急。电催化氧化技术因具有适应性广,氧化性强,无二次污染,反应迅速,设备及其操作简单等优点而日益成为有机废水处理领域的研究热点。阳极材料是电化学氧化法处理有机废水的关键。文章综述了贵金属电极、碳素电极、钛基金属氧化物电极和合成掺硼金刚石薄层电极等常用阳极材料的性能,并对有机废水电催化氧化阳极材料的发展趋向进行了展望。     

生物电化学系统处理难降解有机污染物研究进展

难降解有机污染物广泛存在于水、土壤及大气等环境介质中,严重危害生态环境。生物电化学系统是一种高效处理难降解有机污染物的生物处理技术,通过电化学对微生物的刺激,增强微生物降解污染物的能力,提高污染物降解效率。介绍了生物电化学系统的工作原理,综述了生物电化学系统在处理多环芳烃类化合物、有机染料类化合物、卤代烃类化合物和其他难降解有机化合物的研究应用情况以及生物电化学系统耦合其他降解技术处理难降解有机化合物等方面的研究进展。生物电化学系统是目前去除难降解有机污染物较有前途的方法,分析了生物电化学系统处理难降解有机污染物存在的问题,提出未来可从能代谢难降解有机污染物的电极及电化学活性微生物的筛选、电子转移机制的理论分析2个方面进行深入的研究。     

剩余污泥电解氧化减量化性能研究

进行了电化学氧化减量剩余污泥的研究,探究了不同电压、搅拌速度、电极材料以及电场方向对电解氧化污泥效果的影响。结果表明,在电压6 V、搅拌转速120 r/min、电极材料为石墨条件的优化下,7 h MLSS含量下降83.3%,SCOD提高至2.7 g/L;伏安特性曲线和电镜结果显示,电化学氧化高效作用于细胞破裂,以及可溶性COD(胞液)降解,表明电化学氧化对于剩余污泥降解具有显著效果,是一种前景广阔的污泥减量化技术。     

三维生物电化学法提高污染物去除效能的研究进展

通过对三维生物膜电化学系统的特性进行剖析，总结出该系统具有提高氧化功能的羟基自由基水平、加速电子传递效能、增加降解功能微生物群落富集和活性的能力。通过剖析该系统对污染物高效去除的机理，从反应器构建的工艺参数(电极材料、反应器结构以及电极形状)方面提出了优化方案，对比了系统运行条件对污染物去除性能的影响，并评价其经济性能，最后提出了三维生物膜电化学法未来的发展方向。     

掺硼浓度对金刚石薄膜电极电化学性能影响的研究

以不同掺硼浓度的金刚石薄膜作为电极材料,采用循环伏安法和交流阻抗法研究了电极的电化学性能,着重分析了掺硼浓度对金刚石电极电化学性能的影响.结果表明,随着掺硼浓度的增加,电极的电势窗口略微变小,背景电流也随之变大.在铁氰化钾电解液中,未掺杂金刚石薄膜的电极表面进行的不是可逆反应,而硼掺杂金刚石膜电极表面在反应过程中有着良好的活性和准可逆性;并且随着掺硼浓度的增加,其动力学过程主要受扩散过程控制.金刚石膜电极对苯酚模拟有机污染物的循环伏安实验表明,所考察的三个硼浓度不断增加的电极的氧化峰电流密度分别为0.8,1.9和5.1 mA(cm(2,说明在本实验范围内,金刚石膜电极对苯酚催化氧化作用随着掺硼浓度的增加而增强.     

不同电极活化过硫酸盐处理污染物的研究进展

近些年来活化过硫酸盐在处理水体有机污染物方面得到广泛应用。电化学活化过硫酸盐是一种新型、高效、环境友好且具有良好前景的活化方式。该活化方式能够使目标污染物得到有效降解,而且对pH的适应范围很广。电极材料是影响电化学活化最重要的因素之一。综述了金属电极、金属氧化物电极和碳材料电极在电活化过硫酸盐降解水中有机污染物方面的应用,并讨论了不同电极的活化机理。最后总结了不同材料电极在应用中存在的一些问题,并提出了未来的发展方向。     

有机废水电化学氧化阳极材料的研究进展

阳极材料是电化学氧化法处理有机废水的关键.综述了贵金属电极、碳素电极、钛基金属氧化物电极和合成掺硼金刚石(BDD)薄层电极在内的常用阳极材料的性能,并对有机废水电化学氧化阳极材料的发展趋向进行了展望.     

硼掺杂金刚石膜电极电氧化降解对氯苯酚废水

采用循环伏安法研究了中性介质中对氯苯酚在硼掺杂金刚石(BDD)膜电极上的电氧化行为。提出了一种以BDD膜电极为阳极的电化学氧化降解对氯苯酚废水的新工艺,考察了阳极电流密度、对氯苯酚初始浓度、电解液初始pH、支持电解质浓度等工艺因素对电氧化降解效果的影响。结果表明:在阳极极化电位为1.4～1.6V(vs.SCE)时,对氯苯酚在BDD膜电极表面发生直接电氧化反应,生成易吸附的中间产物,导致电极活性降低;在阳极极化电位高于2.0V(vs.SCE)时,BDD膜电极能够良好地电氧化降解对氯苯酚溶液,该过程是通过直接电氧化过程与间接电氧化过程联合作用实现的。通过考察若干工艺因素对对氯苯酚电氧化降解效果的影响发现,较为理想的工艺参数组合为,阳极电流密度60mA·cm-2、支持电解质浓度10g·L-1、对氯苯酚初始浓度10mmol·L-1、电解液初始pH7。在该工艺条件下,COD去除率达到96.1%,平均电流效率为50.2%。高效液相色谱证实了BDD膜电极能有效地电氧化降解对氯苯酚。     

Effect of electronic structures on electrochemical behaviors of surface-terminated boron-doped diamond film electrodes

In order to analyze the electrochemical behaviors of hydrogen-terminated and oxygen-terminated boron-doped diamond film electrodes, experiments of the cyclic voltammetry and AC impedance spectroscopy have been performed. For the purpose of clarifying the detailed electronic structures of these diamond films, current–voltage spectroscopy curves and XPS spectra have been investigated by scanning probe microscopy and X-ray photoelectron spectroscopy, respectively. For the hydrogen-terminated boron-doped diamond film electrode, its potential window is narrower than that of the oxygen-terminated boron-doped diamond. The impedance results indicate that the diamond film resistances and capacitances corresponding to different surface-terminated boron-doped diamond electrodes vary significantly. The surface band gap of hydrogen-terminated diamond film is narrow with empty surface states in it. In contrast, the surface band gap of oxygen-terminated diamond film is wide and clean. Compared with hydrogen-terminated diamond film, the surface energy bands of oxygen-terminated diamond film bend downwards. Based on their electronic structures, the electrochemical behaviors of the two boron-doped diamond film electrodes have been discussed.     

掺硼金刚石纳米棒电极的制备及电化学性质

Boron-doped diamond nanorods with 300—400nm in diameters and several μm in lengths were successfully fabricated by deposited diamond film onto silicon nanowires using HFCVD methodElectrochemical analysis of glucose at the boron-doped diamond nanorods electrode was studiedCompared with normal flat boron-doped diamond electrode, some unique electrochemical properties were found on the nanorods electrode due to its large surface area and special nanostructuresThe nanorods electrode, as a new type of carbon material electrode, may serve as enabling technology for potential applications in electrochemical analysis     

掺硼金刚石阳极电催化降解新兴抗生素类污染物研究进展

抗生素类药物是目前水环境中出现的一类新兴有机污染物,具有难自然降解、环境刺激性、生物毒性及耐药性等特点,高效去除抗生素类污染物是近年来环境工作者重点探讨的内容。掺硼金刚石（boron-doped diamond,BDD）电极由于自身优异的物理和化学性质,被认作为目前电催化氧化水中有机污染物最为理想高效的阳极材料,但关于BDD阳极在新兴抗生素类污染物的研究情况尚未进行及时的总结。本文首先论述了BDD阳极在电催化氧化有机污染物的降解过程和基于强氧化性物种的电催化氧化机理,进而分析了BDD阳极在电催化降解水中新兴抗生素类污染物的研究进展,探讨了影响抗生素类污染物电催化降解过程的关键影响因素,总结了BDD阳极材料的开发情况,同时,总结了以BDD阳极电催化氧化为基础发展而来的其他水处理联合方法,最后,进一步展望了BDD阳极在未来电催化降解抗生素类污染物存在的问题及未来的重点发展方向。     

新型多孔Ti/BDD薄膜电极电化学氧化降解低浓度茜素红

运用热丝化学气相沉积（HFCVD）的方法制备了以多孔钛为基体的掺杂硼金刚石（porous Ti/BDD）薄膜电极,并测试了它的主要物理性质,SEM表明金刚石相生长良好并且能均匀地分布在基体表面和孔内,Raman光谱表明电极的金刚石相纯而且质量很高。采用循环伏安法研究了酸性条件下茜素红在多孔Ti/BDD电极上的电氧化行为。通过改变阳极电流密度、支持电解质Na2SO4的浓度来研究茜素红在多孔Ti/BDD电极上的电化学氧化降解的效果影响。结果表明：电流密度40 mA/cm2、支持电解质浓度0.5 mol/L为较理想的工艺参数,总电流效率达到30.2%。在相同条件下,发现多孔Ti/BDD薄膜电极氧化降解茜素红与平板Ti/BDD薄膜电极相比具有更高的电流效率。紫外可见光光谱证实了多孔Ti/BDD电极能够有效地电氧化降解茜素红。     

Recent advances in electrochemistry of diamond

Conductive boron-doped chemically vapour-deposited diamond thin film and honeycomb electrodes were examined for various possible applications in electroanalysis and electric double layer capacitor applications, respectively. The possibility of voltammetric study of electrochemical reactions occurring at high oxidation and high reduction potentials was demonstrated at diamond electrodes, taking histamine and carbon tetrachloride as respective examples. High sensitivity and high stability of this electrode were demonstrated for the determination of histamine and sulfadiazine by flow injection analysis method. Nanostructured honeycomb diamond electrodes, prepared by oxygen plasma etching, exhibited a wide potential window similar to that of as-grown film but a capacitance 200 times higher than that of the as-grown film. These results indicate the usefulness of diamond electrode for electroanalysis and double layer capacitor applications.     

影响金刚石膜刀具涂层形貌的因素分析

采用高分辨金相显微镜对硬质合金刀生上沉各的ＣＶＤ金刚石薄膜进行了表面形貌和膜／基横截面组织形貌的观察;并利用该显微镜配备的功能测量了金刚石颗粒大小,膜厚;利用显微镜正焦／过焦观察判断了金刚石薄膜的成膜状况。初步观察结果表明：甲烷浓度和基体钴含量对金刚石薄膜的表面形貌和膜／基横截面组织形貌有显著的影响。     

CVD金刚石膜投资财务分析

文章从经济的角度,通过专业的财务分析,对CVD金刚石膜这一新型材料的投资价值进行研究。研究认为,CVD金刚石膜将成为金刚石材料未来发展的主流,其材料和制品具有广阔的市场前景。因此,投资CVD金刚石膜将获得丰厚的经济回报。     

导电金刚石及其应用

导电金刚石具有不同于普通金刚石的性质。目前有两种类型的导电金刚石：一是金刚石粒,另一是金刚石厚膜。它们的应用包括放电加工用的电极、导电金刚石零件、金刚石砂轮以及精密磨削工具等。     

Production of single crystal diamond needles by a combination of CVD growth and thermal oxidation

Single crystal diamond needles were produced by combining chemical vapor deposition of a thin polycrystalline diamond film and its subsequent thermal oxidation. The deposition process has been carried out in a direct discharge activated hydrogen–methane gas mixture with parameters providing (100) textured diamond film growth. The oxidation has been performed by heating the deposited film in an air atmosphere with a temperature allowing the selective etching of the smallest fraction of the diamond crystallites in the film. As a result of this procedure, perfectly shaped micrometer sized single crystal diamond pyramids were obtained. The pyramids have a rectangular base plane with an apex tip curvature radius of about 2 to 10 nm. The atomic structure of the pyramids was established using high resolution transmission electron microscopy. We propose a model explaining the mechanism of the pyramids' formation.     

Interface and interlayer barrier effects on photo-induced electron emission from low work function diamond films

Nitrogen-doped diamond has been under investigation for its low effective work function, which is due to the negative electron affinity (NEA) produced after surface hydrogen termination. Diamond films grown by chemical vapor deposition (CVD) have been reported to exhibit visible light induced electron emission and low temperature thermionic emission. The physical mechanism and material-related properties that enable this combination of electron emission are the focus of this research. In this work the electron emission spectra of nitrogen-doped, hydrogen-terminated diamond films are measured, at elevated temperatures, with wavelength selected illumination from 340 nm to 450 nm. Through analysis of the spectroscopy results, we argue that for nitrogen-doped diamond films on metallic substrates, photo-induced electron generation at visible wavelengths involves both the ultra-nanocrystalline diamond and the interface between the diamond film and metal substrate. Moreover, the results suggest that the quality of the metal–diamond interface can substantially impact the threshold of the sub-bandgap photo-induced emission.