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采用电化学阳极氧化的方法,以氟化铵水溶液为电解液,在纯钛表面制备了TiO2纳米管阵列。以亚甲基蓝为模拟污染物,考察了TiO2纳米管阵列光催化降解效果。结果表明,TiO2纳米管阵列催化降解效果要好于TiO2薄膜电极,当降解时间为1h、2h、3h和4h时,降解率分别为57.84%、86.44%、93.66%和95.72%;而TiO2薄膜电极的降解率分别为50.18%、76.27%、87.31%和91.53%。在此基础上,考察了阳极氧化电压、氧化时间和焙烧温度对阳极氧化过程的影响规律。结果表明,阳极氧化电压在25V,氧化时间在1h,焙烧温度在500℃时所制备的TiO2纳米管阵列的光催化降解性能最好。 相似文献
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纳米TiO2/Ti管阵列薄膜催化剂的制备和性能 总被引:4,自引:0,他引:4
采用阳极氧化法制备纳米TiO2/Ti管阵列薄膜催化剂,考察了外加电压、反应时间和电解液pH值对催化剂形貌的影响.结果表明,在外加电压20 V,pH值为4.5~5.0,反应6 h的条件下,制得的TiO2管阵列薄膜催化剂管孔形貌清晰、整体分布均匀,管长约为1.8,um,管径约为90 nm.在400℃煅烧2 h后,由无定型转化为单一的锐钛矿型,阵列结构没有崩塌和损毁.在400℃煅烧后的纳米TiO2/Ti管阵列薄膜催化剂具有良好的光催化活性,可与光电协同催化用于降解亚甲基蓝,光催化和光电协同催化降解的降解率分别为21.30%和77.96%. 相似文献
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采用电化学阳极氧化法,在HF—H2O,NH4F—H2O,NH4F—H2O-乙二醇三种不同的电解液体系中,于Ti基底上制备了TiO2纳米管阵列薄膜,并在空气气氛中于500℃进行结晶热处理。以亚甲基蓝为模拟污染物,考察了TiO2纳米管阵列薄膜的光电催化降解效果,并比较了电解催化、光催化和光电催化对亚甲基蓝溶液降解效率的差异。结果表明在NH4F—H2O-乙二醇电解液体系中制备的TiO2纳米管阵列光电催化性能最好。经过340min后,催化效率达到了94.23%。 相似文献
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采用阳极氧化法制备了TiO2纳米管阵列电极。采用场发射扫描电子显微镜(FESEM)和X-射线衍射仪(XRD)表征了电极的表面形貌和晶体结构,应用电化学阻抗谱(EIS)技术研究了不同阳极极化电位下电极的导电性能,应用荧光光谱法研究了电极产生羟基自由基(·OH)的活性,考察了3种支持电解质(Na2SO4、NaNO3和NaCl)对甲基橙(MO)电催化降解效率的影响,通过加入捕获剂探讨了MO分子的降解机理。结果表明,TiO2纳米管阵列电极电极的导电性随阳极极化电位的升高而增强;在电场作用下,TiO2纳米管阵列电极表面生成大量·OH;Na2SO4和NaNO3不参与MO分子的氧化反应,MO的降解符合一级反应动力学模型,而NaCl参与了TiO2纳米管阵列电极电催化降解MO的过程,呈现出复杂的动力学行为;在捕获剂存在的情况下,MO分子仍能发生降解,显示MO分子可在TiO2纳米管阵列电极表面直接氧化。 相似文献
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High-aspect-ratio TiO(2) nanotube arrays formed by anodic oxidation have drawn extensive attention due to their easy fabrication and various excellent optical, electrical and biomedical properties. In contrast to conventional single-layer TiO(2) nanotubes prepared via constant-voltage anodization, we synthesize multilayer TiO(2) nanotube arrays with high surface area by using alternating-voltage anodization steps. This work presents synthesis and growth mechanisms of single-layer smooth TiO(2) nanotubes, bamboo-type nanotubes and double-layer nanotubes, by tuning various parameters such as voltage, time, and water content in the electrolyte. It is found that ion diffusion inside the nanotubes dominates growth of these three structures. A stable pH and ion-diffusion profile allows the steady growth of smooth TiO(2) tubes in NH(4)F-containing ethylene glycol (EG). The addition of a low-voltage anodization step reduces the pH and ion-diffusion gradient in the nanotubes and induces formation of bamboo-type nanotubes and double-layer nanotubes when a second high-voltage anodization is conducted. Ion diffusion through a nanotube takes time; thus formation of lower-layer TO(2) nanotubes costs more time if longer nanotubes are grown in the upper layer, since ions diffuse through these longer nanotubes. This ion-diffusion controlled growth mechanism is further confirmed by tailoring the water content (0-20 vol%) in the electrolyte and the voltage gaps to control the time needed for initiation of lower-layer TiO(2) nanotube arrays. The fundamental understanding of the growth characteristics of double-layer TiO(2) nanotubes presented in this paper offers us more flexibility in engineering morphology, tuning dimensions and phase compositions of multilayer TiO(2) nanotubes. In addition, we synthesize double-layer TiO(2) nanotube arrays composed of one layer of anatase phase and another layer of amorphous phase. 相似文献
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在平面转盘光电液膜反应器的基础上,以纳米管TiO2代替溶胶凝胶法制备的TiO2纳米颗粒结构,以提高对染料废水的脱色效果。在0.5%HF体系和20 V电压下,采用阳极氧化法制得纳米管TiO2膜电极,根据光电响应试验的结果,选取120 min作为氧化时间。以RhB为目标污染物,应用转盘光电液膜反应器,在UV照射下进行脱色研究。结果表明在光催化和光电催化过程中,纳米管TiO2膜电极对RhB的脱色率分别达89%和94%,比溶胶凝胶电极分别提高了66%和10%。最佳脱色条件:转速为80 r/min,偏压为0.8 V。且在处理高浓度的RhB溶液时,纳米管电极的优势更加明显。 相似文献
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TiO2纳米管阵列光催化降解苯酚 总被引:1,自引:0,他引:1
采用电化学阳极氧化法在钛基体上制得了高度致密的、有序的、均匀的TiO2纳米管阵列。用SEM、XRD等对其表面形貌和结构晶型进行了表征和分析。以TiO2纳米管阵列为光催化剂对废水中典型的有机污染物——苯酚进行了光催化降解,考察了影响光催化降解速率的因素。结果表明,在紫外光照下,苯酚水溶液的pH=3、ρ(苯酚)=10.0 mg/L时,具有锐钛矿相结构的TiO2纳米管阵列的光催化效果最好,相同条件下与溶胶凝胶法制备的纳米TiO2颗粒膜的光催化降解速率进行对比,前者比后者提高了近一倍。 相似文献
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向水热均匀沉淀、800℃焙烧制得的高活性、易分离TiO2(TiO2-800)中掺杂金(Au),以光催化降解活性艳红染料X-3B作为模型反应,考察了掺Au量、制备条件、Au的价态等对Au/TiO2-800光催化性能的影响。结果表明,氨水作为沉淀剂,200℃焙烧的0.5%Au/TiO2—800的光催活性较TiO2-800有较大提高,染料X-BB的降解率由93%提高到了100%。还原实验显示,0.5%Au/TiO2-800表面存在的离子态Au能有效提高TiO2-800光催化活性。 相似文献
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向水热均匀沉淀、800℃焙烧制得的高活性、易分离TiO2(TiO2-800)中掺杂金(Au),以光催化降解活性艳红染料X-3B作为模型反应,考察了掺Au量、制备条件、Au的价态等对Au/TiO2-800光催化性能的影响。结果表明,氨水作为沉淀剂,200℃焙烧的0.5%Au/TiO2-800的光催活性较TiO2-800有较大提高,染料X-3B的降解率由93%提高到了100%。还原实验显示,0.5%Au/TiO2-800表面存在的离子态Au能有效提高TiO2-800光催化活性。 相似文献
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Fabrication of high aspect ratio and open‐ended TiO2 nanotube photocatalytic arrays through electrochemical anodization
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Roong Jien Wong Sanly Liu Yun Hau Ng Rose Amal 《American Institute of Chemical Engineers》2016,62(2):415-420
Well‐aligned, high aspect‐ratio and open‐ended TiO2 nanotube arrays secured within a Ti foil (TiO2 nanotubes cartridge) were successfully prepared through the double‐sided anodization method. With ~210 µm of nanotube length, the anodic growth of TiO2 was accelerated and stabilized by the lactic acid‐containing ethylene glycol electrolyte. In the absence of lactic acid, the anodization led to detachment of nanotubes from the Ti foil after 5–6 h of high voltage (80 V) anodization. Transmission electron microscope image and Raman spectrum revealed that the as‐anodized TiO2 nanotube arrays without annealing treatment were partially crystalline anatase and demonstrated photocatalytic activity in the mineralization of formic acid. © 2015 American Institute of Chemical Engineers AIChE J, 62: 415–420, 2016 相似文献
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