葡萄糖在Ti/NanoTiO_2-ZrO_2修饰电极上电催化氧化

在无水乙醇和乙酰丙酮混合溶液中,电解Ti金属制得前驱体Ti(OCH2CH3)4-y(acac)y,再加入ZrCl4,将上述溶液直接水解、干燥后,在450℃煅烧2 h,粉体通过X射线衍射(XRD)分析表明:纳米TiO2-ZrO2粉体呈单分散结构。扫描电子显微镜(SEM)测试表明,颗粒平均尺寸为30~40 nm。通过溶胶-凝胶法制得高活性的Ti/NanoTiO2-ZrO2修饰电极,采用循环伏安研究发现,Ti/NanoTiO2-ZrO2电极对葡萄糖氧化具有高催化活性。在NaBr电解液中,Br-在Ti/NanoTiO2-ZrO2电极表面氧化为Br2,Br2间接电氧化葡萄糖。     

Ti/nano TiO_2-ZrO_2修饰电极电催化还原马来酸制备丁二酸

采用溶胶-凝胶法制备高活性Ti基纳米TiO2-ZrO2膜电极.通过X射线衍射分析表明,纳米TiO2-ZrO2粉体呈微-纳二级结构.扫描电子显微镜测试表明,颗粒平均尺寸约为30 nm.通过循环伏安和恒电流电解技术研究发现,Ti/nanoTiO2-ZrO2电极对马来酸电催化还原制备丁二酸的活性要高于Ti/nanoTiO2电极,反应过程受扩散控制.以钛基氧化钌电极为阳极,Ti/nano TiO2-ZrO2膜电极为阴极进行恒电流电解实验.结果表明,控制电流密度20 mA cm-2,温度60℃,丁二酸的产率达到96%.     

乙二醛在Ti/纳米TiO2-Pt修饰电极上的电催化氧化

采用溶胶.凝胶和电沉积法制备Ti基纳米TiO2-Pt(Ti/纳米TiO2-Pt)修饰电极.X射线衍射(XRD)表明纳米TiO2为锐钛矿型,扫描电镜(SEM)显示Pt纳米粒子在纳米TiO2多孔膜的表面呈现簇分散状态,平均粒径约25nm.通过循环伏安(CV)和计时电流法研究了Ti/纳米TiO2-Pt修饰电极对乙二醛直接电氧化的电催化活性,结果表明,修饰电极对乙二醛的直接电氧化呈现良好的催化活性,在0.60和1.23 V(vs SCE)出现两个氧化峰,二者电流密度分别为16和42 mA·cm2,约为纯Pt电极的2倍和1.5倍,反应过程受浓差扩散控制.     

乙二醛在Ti/纳米TiO2-Pt修饰电极上的电催化氧化

采用溶胶-凝胶和电沉积法制备Ti基纳米TiO2-Pt(Ti/纳米TiO2-Pt)修饰电极. X射线衍射(XRD)表明纳米TiO2为锐钛矿型, 扫描电镜(SEM)显示Pt纳米粒子在纳米TiO2多孔膜的表面呈现簇分散状态, 平均粒径约25 nm. 通过循环伏安(CV)和计时电流法研究了Ti/纳米TiO2-Pt修饰电极对乙二醛直接电氧化的电催化活性, 结果表明, 修饰电极对乙二醛的直接电氧化呈现良好的催化活性, 在0.60和1.23 V(vs SCE)出现两个氧化峰, 二者电流密度分别为16 和42 mA·cm-2, 约为纯Pt电极的2倍和1.5倍, 反应过程受浓差扩散控制.     

Ti基表面NiO修饰纳米TiO2电极材料的制备及电催化活性

在无水乙醇和乙酰丙酮混合溶液中，电解Ti、Ni金属制得电极材料前驱体NiTi_m(OR)_3m+1(acac)_m+1。将其直接水解、干燥后在550 ℃煅烧2 h，制得纳米NiO/TiO₂粉体。通过红外光谱(FTIR)、X射线衍射(XRD)、电子透射显微镜(TEM)测试表明，前驱体中含有乙酰丙酮基[acac^-]，颗粒平均尺寸为20 nm。通过电合成与沉积得到高活性的纳米NiO/TiO₂修饰电极，采用循环伏安和循环方波伏安研究NiO/TiO₂电极在H₂SO₄溶液中的氧化还原行为以及还原草酸的电催化活性。结果表明，NiO/TiO₂电极在1 mol·L^-1 H₂SO₄溶液中有两对氧化还原峰E_pc1=-0.61 V，E_pc2=-1.05 V(vs SCE)，掺杂Ni电极的放电电流明显增大，达75 mA·cm^-2。间接电还原草酸为乙醛酸，收率和电流效率分别达93%和96%。     

Ru0.7Si0.3O2/Ti电极电催化氧化处理硝基苯废水

制备了Ru0.7Si0.3O2/Ti电极,并以该电极作为氧化阳极,不锈钢为阴极,电催化氧化降解废水中硝基苯。 实验结果表明,当硝基苯初始质量浓度为220 mg/L时,最佳条件为：电流密度25×10-3 A/cm2;Na2SO4作为电解质时加入量为8 g/L;溶液初始pH=2。 在此最佳条件下,硝基苯去除率大于85%,TOC去除率大于50%,表明Ru0.7Si0.3O2/Ti阳极能有效去除废水中有机污染物;对中间产物的检测结果表明,硝基苯的降解是阴阳两极协同作用的结果。     

CO在铂修饰的氧化钛电极上电催化氧化行为的研究

通过阴极还原-阳极氧化法制备了Pt—TiO2／Ti电极，研究了CO在该电极上的电化学行为和电极制备条件对CO电催化氧化的影响．结果表明，与Pt电极相比．CO在Pt—TiO2／Ti电极上的氧化峰峰电位负移了100mV，并且表现出较好的稳定性．通过XPS技术对Pt—TiO2／Ti电极进行了表征．发现Pt以金属形式存在，Ti以TiO2形式存在．Pt—TiO2／Ti电极能抗CO中毒的原因可能是因为TiO2的掺杂使引起催化剂中毒的桥式吸附的CO物种在复合催化剂上的吸附率较低所致．     

葡萄糖在纳米Pt/C电极上的电催化氧化

用交替微波法制备纳米PVC催化剂,研究和比较葡萄糖在光亮Pt和纳米Pt/C电极上的氧化行为.实验表明,Pt纳米化后,电极反应过电位降低,动力学速率相应提高,从而使电化学性能得到改善.其催化活性和抗毒化能力大于光亮Pt的可能原因即在Pt纳米化后,大幅度提高了表面积,结果不仅增加其电极活性,而且含氧物也容易接近受毒化的反应点,从而较易氧化毒化物而使电极再次活化.     

羟基新戊醛在Ti/Sb2O5-SnO2电极上的电氧化研究

在以质子交换膜为隔膜的电解槽内, 以硫酸为支持电解质, 羟基新戊醛为原料, 在Ti/Sb2O5-SnO2电极上直接电氧化制取羟基新戊酸. 线性扫描伏安曲线显示, 加入羟基新戊醛使氧化电流密度明显提高, 表明Ti/Sb2O5-SnO2电极对羟基新戊醛氧化有电催化作用. 通过恒电位电解实验研究羟基新戊醛浓度、pH、温度及阳极电位对生成羟基新戊酸选择性和电流效率的影响, 结果表明, pH对选择性和电流效率影响最大.     

纳米SnO2/TiO2电极的制备及其电催化降解间-硝基苯酚

用电化学方法在乙二醇溶液中制备锡、钛醇盐配合物Sn0.75Ti(OCH2CH2OH)(7-x),将电解液水解、干燥后在400℃煅烧2 h,得到纳米级SnO2/TiO2粉体。通过红外光谱(FT-IR)和拉曼光谱(Raman)对电解产物进行测试,纳米SnO2/TiO2粉体通过X射线粉末衍射(XRD)和扫描电子显微镜(SEM)进行表征。实验表明,在有机体系电解得到的纳米SnO2/TiO2粉体颗粒分散较理想,粒径在100～200 nm。再通过溶胶-凝胶法在钛丝表面得到纳米SnO2/TiO2电极,采用循环伏安法研究电极在酸性溶液和间-硝基苯酚溶液中的氧化还原行为和电催化活性。结果表明,纳米TiO2掺杂SnO2电极的氧化峰电流达到143×10-3A/cm2,氧化还原峰电位差明显减小,催化降解间-硝基苯酚的COD去除率达到86.1%,具有较高的电催化活性。     

电镀烧结法制备Ti/SnO2-Sb2O4电极的研究

The Ti/SnO₂-Sb₂O₄ electrode has been prepared by the electroplate-sinter method. The effect of SbCl₃ adding amount and sintering temperature on its electrode lifetime and oxygen evolution potential were investigated by means of EDX, SEM and XRD analysis. The results indicated that the electrode appeared the best performance when the SbCl₃ adding amounts was 0.2g and the sintering temperature was 550℃. In optimized conditions Ti substrate was entirely covered by SnO₂-Sb₂O₄ and the combinations among them were tight. Due to the use of electroplate method, the electrical conductivity, the oxygen evolution potential and the electrode lifetime were increased, so the elec-tro-catalytic activity and the electrochemical stability of the prepared electrode were found to be superior.     

Ni-Coated Diamond-like Carbon-Modified TiO2 Nanotube Composite Electrode for Electrocatalytic Glucose Oxidation

In this paper, a Ni and diamond-like carbon (DLC)-modified TiO₂ nanotube composite electrode was prepared as a glucose sensor using a combination of an anodizing process, electrodeposition, and magnetron sputtering. The composition and morphology of the electrodes were analyzed by a scanning electron microscope and energy dispersive X-ray detector, and the electrochemical glucose oxidation performance of the electrodes was evaluated by cyclic voltammetry and chronoamperometry. The results show that the Ni-coated DLC-modified TiO₂ electrode has better electrocatalytic oxidation performance for glucose than pure TiO₂ and electrodeposited Ni on a TiO₂ electrode, which can be attributed to the synergistic effect between Ni and carbon. The glucose test results indicate a good linear correlation in a glucose concentration range of 0.99–22.97 mM, with a sensitivity of 1063.78 μA·mM⁻¹·cm⁻² and a detection limit of 0.53 μM. The results suggest that the obtained Ni-DLC/TiO₂ electrode has great application potential in the field of non-enzymatic glucose sensors.     

有机体系中纳米TiO2 / ZrO2修饰电极的制备及电催化活性

The complexes Ti(OCH₂CH₂O)₂ and Zr(OCH₂CH₂O)₂ were directly synthesized by using HOCH₂CH₂OH dissolution in 50 mL flask. The nano-ZrO₂ / TiO₂ powders were prepared by a direct sol-gel synthesis using the above solution and followed by drying at 400 ℃ for 2 h. The complexes were characterized by FTIR and ¹H NMR. XRD and TEM were used to investigate the structure of nano-ZrO₂ / TiO₂. The results show that the complexes containing ^-OCH₂CH₂O^- group could prevent the precursor from agglomeration and sintering during the hydrolysis and calcination process. The ZrO₂ / TiO₂ powders of 20～35 nm was thus obtained in a high purity. The highly active nano-ZrO₂ / TiO₂ modified electrode was prepared by using daubing and calcination. The electro-catalytic activities of this electrode in (COOH)₂ were investigated. The discharge current of nano-ZrO₂ / TiO₂ electrode increased obviously. In preparative electrolysis under optimal conditions, the average yield and current efficiency for HOOC-CHO were 84.7% and 91.6 %, respectively.     

CeO2-ZrO2复合氧化物的制备及协同抛光性能

Sub-micrometer ultra fine CeO₂-ZrO₂ mixed oxides have been prepared by milling solid cerium carbonate and zirconium oxy-chloride with ammonia and followed by filtering, drying and calcining procedures. The effects of Ce/Zr molar ratio, milling time and calcining temperature on the phase composition, particle size and morphology, surface charge, as well as the polishing property were investigated. The results show that the mixed oxide calcined at 1 000 ℃ is composed of cubic ceria doped with zirconium and tetragonal zirconia doped with cerium, and the phase composition varies with calcination temperature and the Ce/Zr molar ratio. The monoclinic zirconia is observed when decreasing calcination temperature and shortening milling time, demonstrating that milling and calcining can force the phase transformation from monoclinic zirconia to cerium stabilized tetragonal zirconia and zirconium doped cubic ceria solid solutions. The removal rate for the optical glass polishing varies with Ce/Zr molar ratio. A synergetic polishing effect is found when Ce/Zr molar ratio below 4, and the optimal Ce/Zr molar ratio is 1∶1. At the same time, the cubic ceria content, density, particle size and surface charge all increase when calcination temperature increasing from 800 ℃ to 1 100 ℃. However, the particle morphology changes from disperse quasi-sphere to irregular aggregation and the maximal removal rate for optical glass polishing lies at 1 000 ℃.These facts show that the polishing property of the synthesized ceria-zirconia mixed oxide is affected by the particle physical characteristics comprehensively.     

Al2O3-ZrO2复合膜的制备与表征

以异丙醇铝和氧氯化锆为原料,用溶胶-凝胶法在Al₂O₃中空纤维上制备了Al₂O₃-ZrO₂复合膜。应用TG、DTA、XRD、SEM等测试手段对复合膜的热稳定性、结构、形貌进行了表征。结果表明复合膜的热稳定性比单一由氧化铝或氧化锆制成的膜有显著的提高,在1100℃之前,复合膜以t-ZrO₂存在,1200℃时,出现了m-ZrO₂和α-Al₂O₃相。扫描电镜分析表明,膜表面完整、无缺陷。气体渗透实验进一步表明所得膜具有一定的气体选择性,0.3MPa和0.5MPa下对氮气和氩气的分离因子α分别为1.191和1.185,和氮气与氩气的理论分离因子(α=1.194)相当,说明气体通过膜的扩散以Knudsen扩散传质为主。用等温氮气吸附实验测定了非担载膜的孔径大小和分布,最可几孔径约为4.3nm。     

The effect of B2O3 addition on the crystallization of amorphous TiO2-ZrO2 mixed oxide

The effect of B₂O₃ addition on the crystallization of amorphous TiO₂-ZrO₂ mixed oxide was investigated by X-ray diffraction (XRD), thermogravimetric and differential thermal analysis (TG/DTA). TiO₂-ZrO₂ mixed oxide was prepared by co-precipitation method with aqueous ammonia as the precipitation reagent. Boric acid was used as a source of boria, and boria contents varied from 2 to 20 wt%. The results indicate that the addition of small amount of boria (<8 wt%) hinders the crystallization of amorphous TiO₂-ZrO₂ into a crystalline ZrTiO₄ compound, while a larger amount of boria (?8 wt%) promotes the crystallization process. FT-IR spectroscopy and ¹¹B MAS NMR results show that tetrahedral borate species predominate at low boria loading, and trigonal borate species increase with increasing boria loading. Thus it is concluded that highly dispersed tetrahedral BO₄ units delay, while a build-up of trigonal BO₃ promote, the crystallization of amorphous TiO₂-ZrO₂ to form ZrTiO₄ crystals.     

环己酮肟气相Beckmann重排反应B2O3/TiO2-ZrO2催化剂的失活与再生

对环己酮肟气相Beckmann重排反应制己内酰胺B₂O₃/TiO₂-ZrO₂催化剂的失活原因和再生方法进行了研究。通过对失活催化剂进行N₂吸附、XRD、NH₃-TPD等表征后发现，引起催化剂失活的主要原因是催化剂表面因积炭所引起的酸性改变。失活催化剂在600℃于空气气氛中焙烧8h可完全恢复到新鲜催化剂的水平。     

稀土La掺杂Ti/Sb-SnO2电极的制备及性能研究

采用浸渍法制备稀土La掺杂Ti/Sb-SnO₂电极,以活性艳红X^-3B为目标有机物,考察电极的电催化性能,对制备温度和La掺杂量进行了详细的实验研究,确定了适宜的制备条件为热处理温度450 ℃、La掺杂量0.7%。采用SEM、EDS、XRD、XPS等分析方法表征了电极的形貌、组成及结构。发现掺杂稀土La能降低界面电阻,使Sb元素向电极表面富集,电极中的Sb、La元素分别以Sb⁴⁺、La³⁺的形式存在。对空白电极和La掺杂Ti/Sb-SnO₂电极进行了动电位扫描测定,考察了空白电极和La掺杂Ti/Sb-SnO₂电极的析氧电位;并采用破损法测定它们的电极寿命。结果表明,La掺杂Ti/Sb-SnO₂电极具有更高的析氧电位和更长的电极寿命。