光电催化法测定COD的研究

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	光电催化法测定COD的研究
其他题名	investigation on Photoelectrocatalysis determination of chemical oxygen demand
	田玉华
导师	李新军
	2008-06-02
学位授予单位	中国科学院广州能源研究所
学位授予地点	广州能源研究所
学位名称	硕士
关键词	光催化 Cod 测定 Tio2薄膜电极
摘要	光催化作为一种高级氧化技术在环境治理、环境检测等诸多方面具有潜在的应用前景。光催化技术测定COD的方法，具有快速，没有二次污染，简单、准确、可在线控制等优点。目前光催化测定COD的研究主要集中在采用纯二氧化钛作为电极在三电极体系下测定水中有机物的COD。本论文工作主要考察锰离子掺杂改性二氧化钛、二氧化钛纳米管作为电极对光催化测定COD的影响，并探讨了光催化燃料电池技术测定COD的方法。采用溶胶-凝胶法制备了锰离子掺杂改性的二氧化钛薄膜电极，在三电极体系中，比较该薄膜电极与纯二氧化钛薄膜电极对于测定丁二酸、乙醇、邻苯二甲酸氢钾、α-D-葡萄糖四种有机物的影响。实验结果表明：三电极体系中电子转移的电量与有机物完全矿化所需的化学需氧量（COD）有着内在的关系，在相同的条件下，锰离子非均匀掺杂二氧化钛的薄膜氧化降解丁二酸、乙醇、邻苯二甲酸氢钾、α-D-葡萄糖的速率大于纯二氧化钛薄膜。结合线性扫描伏安（LSV）、阻抗谱等光电化学表征，从锰离子非均匀掺杂引起二氧化钛薄膜光生空穴-电子分离，初步分析了其光电催化活性提高的机理。采用水热合成法制备了钛酸纳米管，然后采用粉末涂敷法制备钛酸纳米管和商用二氧化钛P25薄膜电极。在三电极体系下，考察了钛酸纳米管和P25薄膜作为电极对于测定丁二酸、乙醇、α-D-葡萄糖、混合有机物等的性能。结果表明：在一定有机物浓度范围内，三电极体系的饱和光电流与浓度成一次线性关系。虽然钛酸纳米管的光催化活性仅为P25的1/4，而对于所测的有机物，钛酸纳米管作为电极的饱和光电流是P25纳米粉电极的2~4倍。分析其有机物浓度与饱和光电流之间关系的机理。采用二氧化钛纳米管的薄膜作为光电极，Pt为阴极，Nafion117作为质子传递膜，组装了简易的光催化燃料电池装置，考察了偏压、电解液、pH值等因素对测定有机物含量的影响。结果表明：偏压大于0.2V，饱和光电流随着偏压增加趋于饱和；当NaNO3溶液的浓度大于1.0moL/L时，饱和光电流随浓度的增加趋于饱和； pH在4.8~5.8时，饱和光电流最好。最后，用二氧化钛纳米管薄膜电极测定水中乙醇的COD。关键词：光催化，COD，测定，TiO2薄膜电极
其他摘要	Photocatalysis,as a kind of advanced Oxidation Processes,has potentially applied in many fields,such as environmental treatment, environmental monitoring,et al.A simple,without secondary pollutant,rapid,and sensitive on-line chemical oxygen demand (COD) determination has more meriton photocatalysis oxidative. At present, the determination of COD based on Photoatalysis with pure TiO2 film electrode was mostly investigate in three electrode systems. The effects of COD determination based on photocatalysis was mostly investigate at Mn nonuniform doping TiO2 nanoporouse and TiO2 nanotube film electrod A photocatalysis fuel cell COD determination method was discussed in this paper. The electrode of TiO2 film, doped by Mn ion with nonuniform distribution, which was prepared adopting sol-gel method. Chemical oxygen Demand (COD) was determinated by photoelectrocatalysis method with Mn nonuniform doping TiO2 film electrode. In three electrode systems, the Chemical Oxygen Demand (COD) of four kinds of organic matter, succinic acid, ethanol, potassium hydrogen phthalate, α-D-glucose, was photoelectrochemical determined at Mn-TiO2 film electrode and pure TiO2 film electrode.The data of the experimentation indicated that Chemical oxygen demand is directly quantified by measuring the amount of electron transferred at Mn nonuniform doping TiO2 film electrode during anexhaustive photoelectroncatalytic degradation the organic.The degradation of succinic acid, ethanol, potassium hydrogenphthalate, α-D-glucose was more efficient by Mn-TiO2 film electrode compared with pure TiO2 one. The photoelectrochemistry characterization, EISNyquist plots and LSV, show that Mn non-uniform doping cause the photo-generated carrier separation and photoholes’ enrichment of TiO2 film electrode, which result in better photo catalytic efficiency. Trititanate nanotubes was prepared adopting hydrothermal synthesis method, Trititanate nanotube and TiO2 of P25 film electrowas prepared adopting dip-coating method. In three electode systems, performance of succinic acid, ethanol, α-D-glucose, mixed organic matter was investigated at Film Electrode of trititanate nanotubes and P25. The data of the experimentationindiated that all organic matter investigated, the Saturation photocurrent (Isph) increased linearly with concentration in the low concentration range. photocatalysis action of P25 is four times than photocatalysis action of trititanate nanotubes. Isph of trititanate nanotubes is two or four times than Isph of P25 for measured organic matter. mechanism of Saturation photocurrent and concentration relationships was analyzed. A simple install of photocatalysis fuel cell was assembled with film electrode of TiO2 nanotubes photoanode, Nafion117and Pt cathode. The effects of important experimental conditions, such as applied potential bias, supporting electrolyte concentration and pH,et al on the determination of organic,was investigated. The data of the experimenttation indicated that the steady state Isph values were measured at more +0.2 V at different potential bias. the steady state Isph values was were measured at more 1.0moL/L at supporting electrolyte concentration of NaNO3 were biggest between four point eight pH.and five point eight pH.At last,Chemical Oxygen Demand (COD) for ethanol was determinated by photoelectrocatalysis method with TiO2 nanotube film electrode. Keywords: Photocatalysis, COD, determination, TiO2 film
页数	72
语种	中文
文献类型	学位论文
条目标识符	http://ir.giec.ac.cn/handle/344007/5818
专题	中国科学院广州能源研究所
推荐引用方式 GB/T 7714	田玉华. 光电催化法测定COD的研究[D]. 广州能源研究所. 中国科学院广州能源研究所,2008.

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