TiO_2/ZnO纳米多孔复合膜制备及光催化性能研究

分别采用水热处理和添加有机物的方法制备了TiO2/ZnO纳米多孔复合膜,利用XRD、SEM、TEM和EDS对薄膜进行了分析表征,通过甲基橙降解研究了多孔膜的光催化性能。结果表明:采用这两种方法都可获得具有孔洞特征的多孔复合膜,对添加有机物法制备的多孔膜进行的光催化降解实验表明该多孔膜光催化性能明显优于致密复合膜。     

聚丙烯微孔材料的制备

采用聚丙烯(PP)、硅胶颗粒为基料,以活性炭为微孔剂,经熔融挤出成型制备PP微孔材料。利用光学显微镜观察微孔材料的结构,并用孔径及比表面积测定仪测定微孔材料的微孔参数。着重考察了活性炭用量对微孔材料的结构、比表面积、平均孔径、密度及压缩强度的影响。结果表明:加入活性炭可降低PP对硅胶颗粒的包覆程度。微孔材料的比表面积随活性炭用量的增加而增大,平均孔径随活性炭用量的增加而减小。活性炭质量分数小于20%时,微孔材料的密度和压缩强度都随活性炭用量的增加而增大。     

纳米ZnO催化剂自然光下光催化降解甲基橙

以不同方法自制纳米ZnO,在自然光条件下将其用以光催化降解甲基橙实验,研究了该反应在不同温度下的降解脱色速率。     

二氧化钛柱撑膨润土对染料甲基橙的吸附行为

以sol-gel法制备TiO2溶胶和钇掺杂TiO2溶胶为柱化剂,制备出了TiO2柱撑膨润土和钇掺杂TiO2柱撑膨润土.X射线衍射分析表明经柱撑后的膨润土层间距明显增大,达1.9 nm以上,经500℃煅烧后其层间距稳定在1.8 nm以上.研究了甲基橙在4种TiO2柱撑膨润土上的吸附行为,结果表明4种TiO2柱撑膨润土吸附染料甲基橙的速率和吸附量均较大,其吸附动力学行为均遵循Bangham方程和Langmuir方程所描述的规律.平衡吸附量qe与平衡浓度ρe之间的关系符合Freundlich和Langmuir等温吸附方程.其吸附均为吸热过程,吸附热值在12～17kJ/mol,吸附表现为表面物理吸附和离子交换作用.     

磁性活性炭的制备及吸附去除水中甲基橙的研究

采用沉淀法制备了磁性活性炭,并用磁强计、比表面测定仪、XRD对其进行了表征。研究了磁性活性炭吸附去除水中甲基橙的吸附动力学、吸附热力学。结果表明:磁性活性炭对甲基橙吸附20 min后基本达到平衡,且与拟二级吸附动力学模型拟合较好;在25、40℃和55℃下符合Freundlich方程;吸附焓变、熵变和吉布斯自由能变均为负值,吸附为焓推动作用、自发且放热过程。     

钛基TiO_2纳米管光电催化降解甲基橙

采用阳极氧化法制备了TiO2纳米管,并进行扫描电镜分析。以TiO2纳米管为工作电极,石墨作对电极,对甲基橙溶液进行光电催化降解研究,考察了阳极氧化电压、时间、热处理温度、电解液组成、外加偏压的影响。结果表明,阳极氧化电压为20 V,氧化时间20 min,热处理温度500℃,V(H3PO4)∶V(NH4F)=1∶1,外加偏压为0.6 V时,甲基橙(5 mg/L)经TiO2纳米管光电催化30 min,脱色率达到96.3%。     

Photocatalytic degradation of methyl orange using polythiophene/titanium dioxide composites

Polythiophene/titanium dioxide (PT/TiO₂) composites were prepared via in situ chemical oxidative polymerization, and the obtained composites were characterized by X-ray photoelectron spectroscopy (XPS), ultraviolet–visible (UV–Vis) diffuse reflectance spectroscopy (DRS) and transmission electron microscopy (TEM). Using methyl orange (MeO) as a target pollutant, the adsorption capacities and the photocatalytic activities of the resulting composites were investigated. The results indicate that PT/TiO₂ composites have good adsorption capacities due to the electrostatic attraction between the positively charged composite particles’ surfaces and MeO; the incorporation of PT into the composites enhances the photocatalytic degradation activity for MeO under both UV and visible light.     

水合氧化铁的制备过程对其吸附甲基橙的影响

以硝酸铁为原料,Na OH溶液为沉淀剂,通过恒p H沉淀法在p H为3~9范围内制得4种水合氧化铁(Fh),通过XRD、表面零电荷时p H(p Hpzc)测定、N2吸附-脱附法对其进行表征,以甲基橙(MO)为模拟污染物比较其吸附性能。结果表明,p H为5时制备的Fh(Fh5)对MO的去除率为92.8%,明显优于Fh3(34.1%)、Fh7(67.4%)和Fh9(53.7%)。4种Fh对MO的吸附规律符合Langmuir方程,为单分子层吸附。另外考察了沉淀剂类型(Na OH、NH3·H2O)和Fe(Ⅲ)浓度对Fh5吸附MO的影响。结果表明,以Na OH溶液为沉淀剂、Fe(Ⅲ)浓度为0.2 mol/L时制备的Fh5具有最佳的吸附性能。     

氟掺杂钛柱撑蒙脱石的制备及其除砷应用研究

利用四氯化钛为前驱体,制备了不同氟掺杂量的钛柱撑蒙脱石。通过X射线衍射、傅立叶转换红外光谱、透射电子显微镜及比表面积、孔隙度分析等手段对材料结构进行表征,并考察了不同氟掺杂量的钛柱撑蒙脱石对饮用水中微量砷的吸附作用。结果表明,氢氟酸掺杂量为20 mL的20HF-Ti-MMT形成了钛柱撑结构,材料中的锐钛矿型二氧化钛颗粒粒度分布均匀,结晶度好,材料颗粒均匀,晶型完整,稳定性良好,由于比表面积大和表面羟基含量多等特点对饮用水中微量砷的吸附效果较佳,砷吸附率最高为99.76%。     

Electrochemically assisted photocatalytic degradation of methyl orange using anodized titanium dioxide nanotubes

The TiO₂ nanotubes have demonstrated potential in the photoelectrocatalytic degradation of methyl orange dye (MO). TiO₂ nanotubes were prepared using anodization of titanium foils in phosphoric acid (PA) and ethylene glycol (EG) by mechanical stirring and ultrasonic method. The TiO₂ nanotubes prepared in EG under ultrasound followed by annealing in nitrogen atmosphere showed higher activity towards dye degradation as compared to the stirring method. Dye degradation shows improved activity under an external bias compared to degradation performed in the absence of an external bias. An increase in the external bias from +0.0 to +0.1 V versus calomel electrode (SCE) is sufficient to improve the degradation rates of MO from 22% to 57% within the first 10 min. At +0.1 V, a complete degradation of 40 μM MO is observed within 30 min. The addition of oxidants such as oxygen and hydrogen peroxide demonstrate improvement in the MO degradation.     

Electrochemically assisted photocatalytic degradation of methyl orange using anodized titanium dioxide nanotubes

The TiO₂ nanotubes have demonstrated potential in the photoelectrocatalytic degradation of methyl orange dye (MO). TiO₂ nanotubes were prepared using anodization of titanium foils in phosphoric acid (PA) and ethylene glycol (EG) by mechanical stirring and ultrasonic method. The TiO₂ nanotubes prepared in EG under ultrasound followed by annealing in nitrogen atmosphere showed higher activity towards dye degradation as compared to the stirring method. Dye degradation shows improved activity under an external bias compared to degradation performed in the absence of an external bias. An increase in the external bias from +0.0 to +0.1 V versus calomel electrode (SCE) is sufficient to improve the degradation rates of MO from 22% to 57% within the first 10 min. At +0.1 V, a complete degradation of 40 μM MO is observed within 30 min. The addition of oxidants such as oxygen and hydrogen peroxide demonstrate improvement in the MO degradation.     

基于MOF制备铜碳复合材料及其对甲基橙的降解

以对苯二甲酸和三水合硝酸铜为原料,采用溶剂热法合成金属骨架材料Cu-MOF,以其作为前驱体,在氮气氛围下经过不同温度焙烧得到了铜碳复合材料Cu-MOF-θ(θ=700、800、900、1000℃)。通过XPS、SEM和BET分析了Cu-MOF-θ的微观结构和形貌;考察了Cu-MOF-θ作为类芬顿非均相催化剂催化降解甲基橙(MO)模拟废水的特性,优化了pH、初始MO质量浓度并探讨了Cu-MOF-800的循环使用性。结果表明,Cu-MOF-θ样品为以Cu、C、O为主的多孔片层状结构,尺寸随焙烧温度升高而减小。其中,Cu-MOF-800具有最大的比表面积、孔体积和n(Cu~+)/n(Cu~(2+));在H_2O_2浓度12 mmol/L、催化剂质量浓度1 g/L、反应温度50℃、溶液pH=3、MO质量浓度200 mg/L的条件下,Cu-MOF-800对MO降解效率最好,经过60 min反应,MO的降解率达到99%以上;经过4次循环使用后,Cu-MOF-800的降解率仍然保持在96%以上。     

聚氯化铝残渣制备CaFeAl-LDO及其对甲基橙的吸附

采用聚氯化铝生产中的压滤残渣（PACR）制备CaFeAl-LDO吸附剂,对吸附剂的结构、形貌等进行表征,并考察该吸附剂对甲基橙的吸附效果。结果表明,制备的吸附剂焙烧前具有类水滑石的结构,焙烧后其表面变得疏松多孔,有明显的断层及裂痕。BET分析数据显示,CaFeAl-LDO较PACR比表面积增大近1.5倍,FTIR分析也表明CaFeAl-LDO有效融合了Ca-Al和Ca-Fe型吸附剂的特征峰。吸附实验效果表明,CaFeAl-LDO吸附剂最佳焙烧温度为750 ℃,对甲基橙的吸附符合二级吸附动力学模型,吸附后的LDO经高温焙烧后可以循环使用至少5次。     

Preparation and characterization of layered carbon hybrid framework materials pillared with titanocene

Novel graphene oxide layered hybrid framework materials pillared titanocene organometallic complex were prepared through a facile ultrasound intercalation approach. The products exhibited periodic layered structures with expanded interlayer spacing as characterized by XRD. Raman spectroscopy demonstrated that the skeleton structure of layered carbon still remained after titanocene treatment. Nitrogen sorption analysis indicated that the building blocks of graphene oxide sheets were cross-linked with titanocene molecules to form lamellar porous structures.     

十聚钨酸钠的制备及其光催化降解甲基橙的研究

自制了不同于TiO2的绿色光催化剂十聚钨酸钠(Na4W10O32),通过紫外-可见吸收光谱、红外吸收光谱对制得的产物进行了表征.以紫外灯为光源,研究了Na4W10O32对模拟甲基橙染料废水的光催化脱色性能.实验结果表明,溶液初始pH对Na4W10O32光催化活性有影响,催化剂投加量及甲基橙初始浓度是影响脱色率的重要因素.20mg/L的甲基橙溶液在300W紫外灯辐照下,Na4W10O32质量浓度为0.6 g/L,溶液初始酸度pH=2,光照30 min即可完全脱色.实验利用Na4W10O32光催化降解模拟甲基橙染料废水取得了良好效果,在国内尚未见相关报道,为以后利用多金属氧酸盐光催化降解水中有机污染物的研究提供了参考.     

GO-PANI复合材料对亚甲基蓝和甲基橙吸附性能

将对苯二胺化学接枝在氧化石墨烯(GO)片层边缘,利用其为锚固位点原位氧化接枝了聚苯胺(PANI),得到复合材料GO-PANI。复合材料GO-PANI对染料具有很好的吸附性能,其对亚甲基兰、甲基橙的平衡吸附量高达465、299 mg/g,是纯PANI对亚甲基兰、甲基橙的平衡吸附量的1.88、2.6倍。     

二氧化钛柱撑膨润土催化合成四氢呋喃

通过水热法制备了TiO2-PILC,用XRD、FT-IR、BET等对催化剂进行表征,考察了催化剂制备条件及催化1,4-丁二醇液相环化脱水合成四氢呋喃工艺条件,结果显示：钛/土比为0.025 mol/g,焙烧温度650 K,反应温度190～200 ℃,每克催化剂可处理1,4-丁二醇98 kg以上,原料转化率≥99%,四氢呋喃的选择性≥99.4%,羰基含量≤0.19%,精馏后产品四氢呋喃纯度≥99.7%。     

沉淀法制备纳米ZnO及光催化甲基橙脱色研究

以Zn(NO3)2·6H2O为锌源,(NH4)2CO3和NH3·H2O混合碱为沉淀剂,通过并流沉淀法制备出纳米ZnO粉体,采用XRD和SEM对其进行了表征。以甲基橙为脱色对象,紫外灯(最大吸收波长254nm)为光源,研究了催化剂用量、甲基橙初始浓度、pH值及外加氧化剂(H2O2)对光催化性能的影响。     

Formation of microporous polymeric materials by microemulsion polymerization of methyl methacrylate and 2-hydroxyethyl methacrylate

The investigated microemulsion system consisted of methyl methacrylate, 2-hydroxyethyl methacrylate and water using sodium dodecyl sulphate as surfactant. Ethylene glycol dimethacrylate acting as a cross-linker was also incorporated to enhance the mechanical strengths of the microporous polymeric materials. The polymerization was carried out at room temperature using a reactive redox initiator comprising ammonium persulphate and N,N,N′,N′-tetramethylethylene diamine. The conductivities of the microemulsion samples were monitored during the course of polymerization. The conductivities for a bicontinuous microemulsion before and after polymerization were found to be very similar. In addition, the transformation of microstructures was also examined using a transmission as well as a field emission scanning electron microscope. It is evidenced from the micrographs that microporous polymeric materials prepared from bicontinuous microemulsion polymerization are attributed to numerous coagulations of spherical particles. A possible mechanism for the microstructural transformation is discussed based on the information of conductivity measurements and electron micrographs. © 1996 John Wiley & Sons, Inc.     

Si-Ce/TiO_2的制备及其光催化降解甲基橙的研究

采用水热合成法分别制备了TiO_2、Si-TiO_2、Ce-TiO_2以及Ce和Si共掺杂TiO_2(Ce0.010Si0.10TiO_2)光催化剂,利用XRD和TEM对制备的样品进行了晶型和形貌的表征,并在可见光照射下用其催化降解甲基橙水溶液,考察了催化剂的可见光催化活性。结果表明,对于Si和Ce共掺杂TiO_2,Si的引入可显著提高TiO_2颗粒的分散性,提高其比表面积,而Ce的引入可提高其可见光催化活性;Ce0.010Si0.10TiO_2具有较好的催化活性,其在可见光条件下对模拟废水中甲基橙的降解率达到了95.3%。