金属酞菁敏化二氧化钛可见光催化降解染料废水的研究

研究了染料敏化半导体光催化剂-酞菁镁/TiO_2复合粒子在可见光波段的光催化性能.通过溶胶-凝胶的方法制得TiO_2胶体再进行焙烧,得到二氧化钛粉末和薄膜,再用酞菁镁敏化,制得酞菁镁/TiO_2复合粒子.利用X射线衍射、扫描电子显微镜、红外光谱和X光电子能谱分析等方法对TiO_2和酞菁镁/TiO_2复合粒子的物理性质进行了表征;并以亚甲基蓝作为目标物研究其光催化性能.结果表明,酞菁镁可以敏化二氧化钛,使其吸收波长红移,并具有较好的光催化性能.     

Preparation of PDVB/TiO_2 composites and the study on the oil-water separation and degradation performances

The traditional superhydrophobic materials are not ideal for treating residual pollutants after oil-water separation. In this paper, a simple and economical method was developed for the fabrication of multi-functional superhydrophobic materials PDVB_x/TiO_2 composites, through in situ polymerization. The performance of the superhydrophobic composite was studied. The results showed that the low surface energy of PDVB_(2.5)/TiO_2 composite with the micro-nano scale roughness would result in excellent superhydrophobicity. In addition, the PDVB_(2.5)/TiO_2 composite exhibits optimum effect on the degradation of methyl orange(MO) with the degradation efficiency of 97.8%. What is more, the applications of the composite materials could be expanded to other fields, such as the degradation of drug ciprofloxacin hydrochloride(CIP). Finally, we expanded the application of the PDVB_x/TiO_2 composites to tribology, and found its excellent performance in reducing wear and antiwear.     

Preparation of Au NPs/ZnO NTs Hybrid Array and Its Photo Catalytic Performance for MO

X-ray diffraction, scanning electron microscopy and transmission electron microscopy were employed to investigate the microstructure and morphology of Au NPs/ZnO NTs, and their photo-catalytic capability was assessed to a nicety. The results demonstrated that the diameter and the wall thickness of ZnO nanotube were about 200 and 50 nm, respectively. The diameter of Au nanoparticle was about 30 nm. The characterization on the photo-catalytic capability of the Au-ZnO nanotube hybrid indicated that the degradation of methyl orange was 80% within 4 h. Controlled experiments have shown that Au-ZnO nanotube hybrid presents superior photo-catalytic capability to both bare ZnO nanorod and Au-ZnO nanorod hybrid indicated that the degradation procedure of methyl orange.     

高光催化活性锐钛矿型纳米TiO2溶胶的低温制备

以四氯化钛和氨水为原料,在常温条件下通过两步法制备出TiO2溶胶。通过TEM和XRD分析测试表明,TiO2溶胶粒度小于10 nm,并存在一定数量的锐钛矿型晶相结构。在充足太阳光照8 h后,用质量分数0.2%的甲基橙溶液和0.2%的亚甲基兰溶液的降解试验测试其光催化性能。结果显示,温度为80℃时制得的TiO2溶胶对甲基橙和亚甲基兰的降解率就已超过90%,催化效果明显。     

磁性纳米TiO2/Fe3O4复合材料的制备及光催化降解性能

采用均匀沉淀法在Fe3O4表面包覆TiO2,制备新型纳米TiO2/ Fe3O4光催化材料,并通过改变pH值、温度、TiO2/Fe3O4的比例和硫酸钛浓度等得到材料制备的最佳条件.用X射线衍射分析了复合颗粒的形态结构及包覆情况.通过可溶性染料活性艳红X-3B的降解反应,考察了光催化活性.结果表明,用最佳条件制备的复合材料对活性艳红的脱色率达97.12%.光降解动力学结果表明:对活性艳红X-3B染料的光催化降解反应符合一级反应动力学.     

纳米TiO2薄膜光催化性能的研究进展

TiO2薄膜的光催化性能研究前景广阔,具有纳米结构特征(如晶粒尺寸纳米化,大比表面积,高孔隙度等)的TiO2薄膜的光催化活性明显改善.文中主要探讨了TinO2薄膜的光催化性能,介绍了晶型、比表面积、粒径等形态结构以及金属离子掺杂、半导体耦合、贵金属沉积、光敏化等多种改进技术对其光催化性能的影响,及其研究进展情况.     

微波辐射制备TiO_2薄膜光催化性能研究

采用微波辐射法由溶胶制备出TiO2薄膜,用XRD和TEM对催化剂进行了表征。以甲基橙为模拟污染物,考察了微波功率和膜层厚度对TiO2光催化活性的影响,并实际考察了TiO2薄膜对啤酒废水的降解效果。结果表明:制备的TiO2薄膜具有较高光催化活性,微波功率300 W时光催化活性最大,对啤酒废水具有良好的处理效果。     

自蔓延-溶胶凝胶法制备尖晶石型纳米ZnFe_2O_4及其光催化性能研究

采用自蔓延-溶胶凝胶法制备纳米ZnFe2O4,使用ICP等离子体发射光谱仪、透射电子显微镜和X射线衍射仪等设备研究了铁酸锌晶相组成、粒度大小和形貌。结果表明,产物具有尖晶石结构,平均粒径约为10 nm。以高压汞灯为光源,ZnFe2O4为光催化剂,对甲基橙溶液进行光催化降解实验。结果表明,经过4 h后甲基橙的脱色率达到了98.5%,表现出优异的催化活性。     

TiO2／Mg（OH）2复合材料对有机污水中甲基橙的光催化降解动力学的研究

采用溶胶一凝胶法制备了纳米TiO2,并以TiO2和镁盐溶液为前驱物用氨气鼓泡法制得了TiO2／Mg（OH）2复合材料．利用氢氧化镁在水溶液中较强的吸附能力和TiO2对有机物的催化降解作用,研究TiO2／Mg（OH）2复合材料对有机污水中的甲基橙暗反应吸附规律和光反应催化降解性能．结果表明：当Ti02／Mg（OH）2加入量为1g·L^-1。时,在可见光下照射180min后,对有机污水中含20mg·L^-1的甲基橙的降解率达到98．00％,同时在同等条件下选用国家标准（30mg·L^-1亚甲基蓝溶液）作为参照时,降解率可达99．20％．TiO2／Mg（OH）2复合材料对污水中甲基橙的催化降解反应较好地符合Langmuir动力学模型,可用一级反应动力学方程进行描述．     

Ti O2／Si O2复合光催化剂制备工艺参数优化及其表征

先以无机钛盐、硅酸盐为原料制取聚合硅酸硫酸钛,再通过液相水解法制得TiO2/SiO2复合光催化剂,并用SE M、X R D、BE T和甲基橙脱色率对复合光催化剂进行表征. 结果表明,TiO2/SiO2复合光催化剂制备优化工艺参数为：Ti（S O4）2作钛源、Ti/Si摩尔比为12 ： 1、水解反应p H值为6、煅烧温度为650oС,以此条件制备的复合光催化剂对甲基橙脱色率可达98 .6 %以上;TiO2/SiO2复合光催化剂为一种分散均匀的纳米级球形颗粒,其成分为以锐钛矿为主的TiO2,SiO2的复合有效抑制了TiO2晶粒的生长,同时提高了TiO2的热稳定性.     

纳米二氧化钛粉体光催化染料脱色的研究

以钛酸四丁酯为原料,采用水解法制备了纳米二氧化钛粉体.经XRD对制得的粉体进行了表征.以水解法制得的二氧化钛粉体,利用紫外光催化反应装置,考察了溶液初始浓度变化、催化剂投加量以及光催化时间对甲基橙降解率的影响.结果表明:随着溶液初始浓度增加,甲基橙的降解率降低;TiO2粉末投加量为0.8 g/L时,其具有良好的光催化脱色性能,经7 h光照,甲基橙染料废水脱色效果好.     

Kinetics analysis of Ni-TiO_2 composite system during initial stages of electro-crystallization

The initial stage of Ni-TiO_2 composite system electrodeposition on glassy carbon electrode from an acidic solution of nickel sulfate was investigated using cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS). Analysis of current density-time transients was performed using the nonlinear fitting procedure and electrochemical impedance spectroscopy was simulated by Z-view software. Besides, the surface morphology of Ni-TiO_2 co-deposition at the initial stage was observed by scanning electron microscopy (SEM). The results show that, in the case of low overpotential (-790 mV vs SCE), the presence of TiO_2 particles in the plating bath makes the nucleation relaxation time tmax decreased clearly. Meanwhile, the electro-crystallization of Ni-TiO_2 system follows a Scharifker-Hills (SH) progressive nucleation/growth mechanism. While in the case of higher overpotential, the presence of the TiO_2 particles in solution makes the nucleation relaxation time tmax increased. At -850 mV (vs SCE), the co-deposition of Ni-TiO_2 system meets SH instantaneous nucleation/growth mechanism. The results of impedance spectra show that the appearance of the characteristic inductive loops represents the nucleation/growth of nickel and the presence of TiO_2 particles reduces the charge transfer resistance of solution. The SEM observation confirms that TiO_2 particles can be considered as favorable sites for nickel nucleating.     

Highly Efficient Removal of Organic Dyes by Novel As-synthesized AgBr/montmorillonite Composite

A facile deposition method has been developed for large-scale synthesis of visible-light-driven AgBr/montmorillonite composite catalyst for the first time. The as-synthesized samples were characterized by X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), Fourier transform infrared spectroscopy(FT-IR), transmission electron microscopy(TEM), UV-vis diffuse reflectance spectroscopy(UV-vis DRS) and Brunauer-Emmett-Teller(BET) surface area analysis, respectively. Through the combined action of adsorption and photodegradation, the as-prepared AgBr/montmorillonite composite exhibited a higher removal efficiency for rhodamine B(RhB) than that of Na-montmorillonite and AgBr. For the methyl orange(MO) removal, the AgBr/montmorillonite composite possessed a superior photocatalytic performance compared with Namontmorillonite and AgBr. The enhanced photocatalytic activity of AgBr/montmorillonite composite can be attributed to the effective separation of the electron-hole pairs. In AgBr/montmorillonite suspension, the superoxide radicals are the main reactive oxygen species for dye degradation under visible light illumination.     

TiO2-SiO2复合气凝胶的制备及其分解甲基橙的研究

采用溶胶一凝胶工艺,经超临界干燥,600℃、2h煅烧制得TiO2-SiO2复合气凝胶,其中Ti02为锐钛矿型,Si02为无定形;以甲基橙为模拟废水,TiO2-SiO2气凝胶分解甲基橙的浓度范围为≤100mg／L,分解速率随着时间的变化而变化,前期呈线性关系,后期呈曲线关系;最大分解甲基橙的量约为30mg甲基橙／g气凝胶,采用400℃煅烧1h的活化方式可使气凝胶的重复使用寿命大于3次。     

Photocatalytic Degradation of Methyl Thionine Chloride in Aqueous Solution over Nanometer （ CdS/TiO2 ）/MCM-41

（ CdS/ TiO2 ）/ MCM-41 loaded nanometer photocatalyst was prepared by the sol-gel method and dipping process, the photocatalytic degradation of methyl thionine chloride in water was investigated by using the photocatalyst. The experimental results show that the optimum concentration of CdS over TiO2 was 3% （ molar ratio ）, the photocatalytic activity was enhanced when making TiO2 the anatase ptase with a rise of the roasting temperature, and the carrier, mesoporous molecular sieve MCM-41, was beneficial to improving the photocatalytic activity of TiO2 for photocatalytic degradation of methyl thionine chloride. The morphology and the crystalline phase of the photocatalyst were discussed by means of XRD and SEM techniques, and the reaction mechanism of catalytic properties was also discussed.     

Highly Efficient Synthesis of Environmentally Friendly Ag-modified TiO_2 Nanoflowers to Enhance Photocatalytic Performance

Ag-modified TiO_2 nanoflowers were prepared using a two-step process. The experimental process is green and free from contamination and can be synthesized directly at room temperature. Compared with pure TiO_2, Ag-modified TiO_2 enhances the absorption of visible light and effectively promotes the detachment of photoelectron pairs, Ag-TiO_2 has a significantly enhanced visible light response activity to photodecomposition of methyl orange(MO). It is shown that the strong interaction between Ag nanoparticles and TiO_2 enhances the photocatalytic activity of TiO_2 nanoflowers. The self-made open-air reactor was used to test the photocatalytic performance of different samples. The results showed that Ag-modified TiO_2 nanoflowers had excellent photodegradation ability. After repeated photodegradation of MO, Ag-modified TiO_2 nanoflowers showed good stability.     

Fabrication and Photocatalytic Activity of Ag_3PO_4-TiO_2 Heterostructural Nanotube Arrays

To extend the absorption capability of TiO_2 into visible light region and inhibit the recombination of photogenerated electrons and holes,we put forward an effective strategy of the coupling of TiO_2 with a suitable semiconductor that possesses a narrow band gap.Meanwhile,Ag_3PO_4-TiO_2 heterostructuralnanotube arrays were prepared by the two-step anodic oxidation to obtain the TiO_2 nanotube arrays and then by a deposition-precipitation method to load Ag_3PO_4.The samples were characterized by field emission scanning electron microscopy(FESEM),energy dispersive spectrometry(EDS),X-ray diffraction(XRD),and UV-vis diffuse reflectance spectroscopy(UV-vis DRS).The experimentalresults showed that Ag_3PO_4 nanoparticles were uniformly dispersed on the highly ordered TiO_2 nanotube arrays,which increased the visible-light absorption of TiO_2 photocatalyst.The photocurrent density and photocatalytic degradation of methylorange indicated that the performance of Ag_3PO_4-TiO_2 heterostructuralnanotube arrays was better than that of the TiO_2 nanotube arrays,which could be attributed to the effective electron-hole separation and the improved utilization of visible light.     

TiO_2薄膜降解甲基橙动力学研究

采用450 W汞灯做光源,对TiO2薄膜光催化氧化甲基橙进行动力学研究。结果显示：TiO2薄膜光催化氧化甲基橙的动力学可用Langmuir-Hinshelwood（L-H）方程描述。甲基橙初始浓度≤20 mg/L时,TiO2薄膜光催化氧化甲基橙表现为一级反应;甲基橙初始浓度≥24 mg/L时,则表现为零级反应。     

纳米TiO2／高岭土复合材料的显微结构分析研究

将光催化剂负载在无机矿物表面,制备一定形状的滤料,不仅提高了光催化材料的活性,也有利于回收再利用。研究制备的纳米TiO_2/粘土复合光催化剂降解甲基橙模拟废水效果比较显著,通过能量色散X射线(EDX)谱和透射电镜(TEM)分析照片和图谱,证明TiO_2确实能附着在了煅烧高岭土的表面,有助于进一步探索提高光催化氧化反应效率的方法与途径,对实际的废水处理也有很好的指导意义。     

Degradation of Formaldehyde and Benzene by TiO_2 Photocatalytic Cement Based Materials

A novel photocatalytic cement based material was prepared. The distribution of TiO_2 on the surface of cement was characterized by scanning electron microscope(SEM) and X-ray diffraction(XRD), which showed the relationship of photocatalysis and presence of TiO_2. TiO_2 also had an impact on cement hydration, which was studied by thermal analysis. With 300 W UV illuminations, formaldehyde and benzene were degraded efficiently by the prepared photocatalytic cement based materials. 15wt% TiO_2/cement showed the highest degradation efficiency and capability. The results show that formaldehyde and benzene can be degraded within 4 and 9 hours, respectively. Besides, inorganic ions can induce TiO_2 agglomeration. As a result, the presence of inorganic ions in cement is unfavorable for degradation. The photocatalytic cement based materials were fabricated and the degradation efficiency of formaldehyde was measured on building roof under sunlight illumination. Formaldehyde in glass chamber can be degraded thoroughly within 10 days.