Preparation and photocatalytic activity of Gd-doped TiO2 nanofibre

In order to realize the photocatalysis of TiO2 in the sunlight and directly apply it to waste water treatment, the Gd-doped TiO2 nanofibre was synthesized using two-step synthesis method as follows： Firstly, potassium carbonate, titanium dioxide and proper gadolinium oxide （dopant） were calcined in the muffle at high temperature and the doped gadolinium K2Ti4O9 fibres were obtained; secondly, the fibre was heated using glycerol as solvent until Gd-doped TiO2 nanofibres were obtained. The synthesized samples were characterized using scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The results show that Gd-doped TiO2 nanofibre heat-treated by glycerol solvent can inhibit the agglomeration, so the grain diameter of the fibre is smaller than that without heat-treated with glycerol. Meanwhile, the diameter of the fibre decreases with the increase of the heating temperature and time. 97%- 98% of Gd-doped TiO2 nanofibre is anatase. The photocatalysis results showed that the photocatalysis activity of Gd-doped TiO2 nanofibre is just a little lower than that of TiO2 powder.     

TiO2对堇青石微晶玻璃结构及性能的影响

采用IR、XRD、SEM等现代测试方法，着重探讨了晶核剂TiO2对堇青石微晶玻璃的结构与性能的影响。IR研究表明，在经低温热处理的样品中检测到有四配位的钛存在，但在经高温热处理的样品中却未检测到六配位的钛离子的吸收峰，这可能是由于生成的含钛晶相太少，红外光谱未能敏感地检测到。根据微观结构和性能测试结果，发现晶核剂TiO2最佳添加量为质量分数5％，其制备的微晶玻璃的综合性能最佳。     

Comparative study on photocatalytic properties of TiO_2 nanoparticles prepared in acidic medium and basic medium by hydrothermal method

In order to investigate the difference of phtotocatalytic propenties of TiO_2 samples prepared in different pH conditions, TiO_2 nanoparticles were prepared in acidic medium and basic medium by a hydrothermal process,respectively.The samples were characterized using XRD,TEM, BET,XPS,surface photovoltage spectroscopy(SPS)and field-induced surface photovoltage spectroscopy(FISPS).Effects of temperature and pH in the hydrothermal process on particle sizes,specific surface areas,and photocatalytic properties of the TiO_2 nanocrystalline were investigated.The experimental results indicate that the photocatalysis activity of TiO_2 nanoparticles prepared in basic medium (B-TiO_2) is superior to that in acidic medium (A-TiO_2),which is ascribed to the difference of surface state between A-TiO_2 and B-TiO_2.     

Gd掺杂BiVO4纳米粉体的制备及其光催化性能

采用水热法制备了单斜相白钨矿结构的Gd掺杂BiVO4粉体。采用X-射线粉末衍射、扫描电子显微镜和紫外一可见吸收光谱对样品进行表征。研究了不同浓度Gd掺杂BiVO4纳米粉体的晶相组成、形貌和光催化性能的影响。结果表明,Gd掺杂BiVOt粉体在可见光下的催化活性优于纯相BiVO4粉体,Gd掺杂量为2％的样品对罗丹明B催化效果最佳,在100min内对罗丹明B溶液的分解率达98％。     

Ni2P微球的溶剂热合成与表征

以氯化镍作为镍源,无水乙醇和水作为混合溶剂,采用硬脂酸钠辅助的溶剂热法成功地制备了Ni2P微球.X射线粉末衍射（XRD）、扫描电子显微镜（SEM）分别对所制备样品的结构、形貌进行了表征.结果表明：所制备的Ni2P具有纯的六方相结构,形状为微球,其直径介于2～4μm之间.硬脂酸钠用量、反应温度、反应时间及溶剂配比等对样品尺寸、形貌及微球形成过程等均有一定的影响.通过对比实验得出Ni2P微球的最佳条件是硬脂酸钠的质量百分数为0.42%,VH20∶VEthanol=1∶1,反应温度为180℃,反应时间12h.     

Preparation and characterization of high photoactive TiO2 catalyst using the UV irradiation-induced sol-gel method

High photoactive TiO2 catalyst was prepared using the sol-gel method through UV irradiation during the formation stage of nuclei. The surface morphology and microstructure of the prepared catalyst were characterized using scanning electron microscopy （SEM）, X-ray diffraction patterns （XRD）, and Fourier transform infrared spectroscopy （FF-IR）. The photoactivity was evaluated by the degradation of methylene blue. The results show that the photocatalysis of the prepared catalyst is higher than that of conventional heat-treated particles. The higher photoactivity is a combined result of favorable microstructure, appropriate hydroxyl groups, and active sites of Ti^3＋ ions on the surface of TiO2. It is concluded that the ultraviolet irradiation-induced sol-gel method is an effective method to enhance the photocatalysis of TiO2.     

Preparation, characterization and photocatalytic activity of N-doped TiO_2 nanocrystals

N-doped TiO_2 nanocrystals were prepared using titanium alkoxide as precipitant with different proportional materials. The products were characterized by X-ray diffraction,scanning electron microscopy,transmission electron microscopy, and UV-vis diffuse reflectance spectra. It is confirmed experimentally that the photocatalytic activity of N-doped TiO_2 is much higher than that of Degussa P25, when used for the degradation of crystal violet.The degradation kinetics follows an apparent first-order reaction,which is consistent with a generally observed Langmuir-Hinshelwood mechanism. The doping of TiO_2 with nitrogen significantly increases the absorption in the region of visible light. The energy of the band gap of N-doped TiO_2 is 2.92 eV. The better performante of N-doped TiO_2 can be explained by the fact that it is also excited with longer-wavelength light.     

载银TiO2/沸石催化剂的制备、表征以及光催化性能的研究

为获得高活性的负载型TiO2光催化剂，通过硝酸银溶液浸渍-紫外光照的方法获得载银的TiO2/沸石催化剂.银改 性的TiO2/沸石催化剂光催化性能较改性前大大提高.最佳硝酸银浸渍液浓度为10-3mol/L,此时该催化剂的光催化性能接 近纳米TiO2粉末（Degussa P25）,但进一步升高硝酸银浸渍液浓度，光催化性能又降低.实验通过X-射线衍射（XRD）和 透射电镜（TEM）对载银TiO2/沸石催化剂的表征,结果表明,金属银对电子的捕获使得电子-空穴对有效分离， 从而使银 改性光催化剂的活性提高.     

分级结构纳米ZnO的制备及其光催化性能研究

采用水热合成法,以Zn(CH3COO)2.2H2O和NaOH为原料,糊精为形貌控制剂,在120℃条件下合成了纳米ZnO样品.利用粉末X射线衍射、扫描电子显微镜、透射电子显微镜和高分辨透射电子显微镜对所合成的ZnO样品进行了结构和形貌的表征.分析结果表明,所合成的ZnO样品具有六方纤锌矿结构,且样品中含有大量由ZnO纳米片组装而成的"花状"分级结构纳米颗粒,花状分级结构中纳米片的平均厚度约50 nm.光催化降解实验结果表明,所合成的花状分级结构纳米ZnO具有很好的光催化性能.     

管载二氧化钛凝胶镀膜光催化清除乙烯气体

报道了用sol gel方法在玻璃管上制备二氧化钛薄膜对清除乙烯气体的光催化实验,研究了二氧化钛一次镀膜对乙烯浓度随催化反应时间的变化关系。结果发现,二氧化钛镀膜有较好的清除乙烯的效果,当反应进行到46h时乙烯气体的色谱峰完全消失,即乙烯气体已经被完全清除掉,对相同处理条件下的二氧化钛粉体做XRD分析知该条件下的二氧化钛为锐钛矿晶型。     

液相合成不同形貌的Cu_2O微晶

以乙酸铜为铜源,L-抗坏血酸为还原剂,采用简单的液相反应制备不同形貌的Cu2O微晶,并进行了表征。考察了温度、反应物浓度、表面活性剂种类等条件对Cu2O微晶粒径及形貌的影响,初步探讨了Cu2O微晶的生长机理。实验结果表明:通过改变表面活性剂的种类,可以选择性地制备出不同形貌的Cu2O微晶。以PVP为表面活性剂时制备的是直径约为1μm的Cu2O微球,以PEG为表面活性剂时制备的是边长约为700 nm的Cu2O立方体。     

Fe^3＋掺杂TiO2纳米薄膜及其光催化性能

用溶胶-凝胶法制备了Fe^3＋掺杂纳米TiO2薄膜，研究了不同Fe^3＋掺杂浓度的TiO2薄膜材料的光学性能、晶体结构和光催化性及三者之间的关系，并对相关机理进行了探讨．研究表明：铁掺杂量的不同使TiO2材料的光学性能、晶胞参数及光催化性等发生变化，其中以Fe^3＋掺杂0．3％～0．4％（摩尔分数）时具有最好的光催化性能，此时纳米TiO2薄膜具有锐钛矿结构，可见光透过率大于70％，紫外吸收限为366nm，比未掺杂的红移了6nm．     

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.     

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。     

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.     

玻璃管载二氧化钛粉体对乙烯气体的光催化效应

报道了玻璃管上负载光催化TiO2粉体对清除乙烯气体的光催化的实验研究。结果发现，玻璃管载二氧化钛粉体有较好清除乙烯的效果，当反应进行到45h时乙烯气体的色谱峰完全消失，即乙烯气体已经被完全清除掉．对相同处理条件下的二氧化钛粉体做XRD分析得知该条件下的二氧化钛为锐钛矿晶型。在紫外区域作吸收曲线发现光催化TiO2紫外吸收边发生蓝移，产生量子效应。     

玻璃管载二氧化钛粉体对乙烯气体的光催化效应

报道了玻璃管上负载光催化TiO2粉体对清除乙烯气体的光催化的实验研究。结果发现,玻璃管载二氧化钛粉体有较好清除乙烯的效果,当反应进行到4.5h时乙烯气体的色谱峰完全消失,即乙烯气体已经被完全清除掉,对相同处理条件下的二氧化钛粉体做XRD分析得知该条件下的二氧化钛为锐钛矿晶型。在紫外区域作吸收曲线发现光催化TiO2紫外吸收边发生蓝移,产生量子效应。     

溶剂热法制备CuSe纳米线薄膜

以铜片和硒粉为原料,苯为溶剂,通过调控反应物的配比、反应物浓度、反应温度和反应时间等因素,采用溶剂热法直接在铜基底上制备出六方晶系的硒化铜纳米线薄膜.分别利用X-射线转靶衍射仪(XRD),场发射扫描电子显微镜(FESEM),透射电子显微镜(TEM)表征了产物的晶体结构与形貌,探索了CuSe纳米线薄膜的形成过程,并使用荧光分光光度法(PL)对最终产物的性质进行了表征.实验结果表明:这种CuSe纳米线的直径为100～200 nm,长度为5μm,其荧光发光峰为301 nm.     

纳米级金属氧化物的合成及其性质比较

以表面活性剂溴化十六烷基三甲胺（CTA）为分散剂，采用溶胶-凝胶法合成了三种金属氧化物纳米材料（纳米Fe2O3、ZrO2和ZnO），运用透射电镜及BET对产品进行了表征．考察了pH值、反应物用量、灼烧温度、灼烧时间等因素对产品平均粒径和比表面积的影响，比较了三种纳米材料的合成条件、稳定性和光催化活性．结果表明：在最佳合成条件下，产品的平均粒径为20～35nm，且粒径分布较均匀，总产率大于80％．纳米Fe2O3、ZrO2有很强的稳定性，而纳米ZnO具有较高的光催化活性．     

常温常压气-固光催化CO2加氢合成一碳化合物的研究

大气中ＣＯ２含量的增加是导致最严重环境污染－－温室效应的主要原因,因此,人们对ＣＯ２的固定及利用越来越重视,目前对水溶液悬浮体系光催化还原ＣＯ２研究得比较多,气－固光催化体系中,常温常压下合成ＣＯ２＋Ｈ２为有机物少有报道。通过对几种ＴｉＯ２型催化剂在悬浮体光催化体系中ＣＯ２催化活性的比较,选择了活性较高的Ｐｄ／ＲｕＯ２／ＴｉＯ２催化剂,采用原位红外的实验方法对ＣＯ２加氢反应及其产物进行了研究,结果