与Si集成的溶胶—凝胶法制备的TiO2—SiO2复合薄膜的应力分析

采用激光束反射偏转法测量了用溶胶－凝胶法在Ｓｉ（１１）基片上制备的ＴｉＯ２－ＳｉＯ２复合薄膜的曲率半径。由此计算出薄膜的热应力，应力和本征应力。研究了工艺过程与薄膜应力的关系，其应力随热处理温度的增加而由张应力转变为压应力；当热处理温度较低时，随膜厚的增加，其应力增大，而最终导致膜的开裂，薄膜的最大不开裂厚度随热处理温度和ＴｉＯ２含量的增加而增加。     

锐钛型纳米TiO_2光催化性能的研究

以TiCl4为原料,采用沸腾回流强迫水解法制备纳米TiO2,用XRD、TEM对粉体进行表征。采用甲基橙溶液进行光催化降解试验,研究了TiO2的煅烧温度、添加量以及溶液的初始pH值对光催化性能的影响。实验结果表明,当溶液pH=2,TiO2煅烧温度为600℃,添加量为0.8 g/L,光催化75 min甲基橙的脱色率为90.87%。     

超声法制备TiO2纳米棒及其光催化性质的研究

研究了TiO2纳米棒的制备和形成机理及其在光催化降解活性艳红中的应用。采用超声法,以TiCl4为原料,制备了纳米TiO2。SEM结果显示所制备的TiO2为棒状结构,直径30 nm左右,长约200 nm。比表面积为60.500 7 m2/g。XRD显示其为金红石型晶体,700℃烧结后结晶程度增强,形貌保持不变,比表面积降到37.963 2 m2/g。超声法制备的TiO2纳米棒700℃烧结后应用于光催化降解活性艳红时,降解率高达98.94%,表现出优于P25的催化活性。     

金属离子掺杂纳米TiO2光催化研究进展

综述了近年来金属离子掺杂纳米TiO2光催化的研究现状,对其掺杂机理、制备方法(溶胶–凝胶法、沉淀法、浸渍法、水热法等)和影响TiO2光催化效率与光谱响应范围的因素,如掺杂金属离子的种类、浓度、能级、电子构型、半径、化合价等进行了探讨,并对今后的研究作出了展望。     

光催化纳米TiO2/ACF复合滤料净化空气性能的试验研究及环境影响因素分析

通过光催化降解甲醛的静态和动态试验表明,TiO2/ACF复合滤料对甲醛的净化率均比ACF滤料净化效果好,对光催化纳米TiO2与ACF协同作用提高净化率作了分析,并阐述了环境因素对净化效果的影响。     

纳米TiO2光催化杀灭大肠杆菌的超微结构研究

在近紫外光的照射下，纳米TiO2具有较强的光催化灭茵效果。用透射电子显微镜较完整地研究纳米TiO2光催化杀灭大肠杆菌的超微结构变化。结果表明，纳米TiO2可直接或间接作用于大肠杆菌；光催化过程中产生的氢氧自由基等活性氧类物质可导致大肠杆菌的外壁和质膜严重破损、断裂；胞浆流出；细胞质凝聚；类核区解体和丝状染色质消失。本研究为探讨纳米TiO2光催化灭茵机理提供了直观的证据。     

铁氮共掺杂制备TiO_2及其蓝光下的光催化性能

用硝酸铁和盐酸羟胺分别作Fe源和N源,在TiO2溶胶中同时引入Fe和N,一步合成得到Fe、N共掺杂的纳米TiO2粉末。用XRD等技术研究了焙烧温度和N源量对其晶相结构的影响,并用低功率蓝光LED作光源测试其光催化性能。结果表明,400℃焙烧的Fe、N共掺杂TiO2粉末具有最好的催化性能,2h内对若丹明B的降解率达68.0%。增加N源量,有利于Fe在TiO2晶格中扩散,减小晶粒度;Fe、N共掺杂对TiO2的催化性能具有协同作用,其催化能力明显优于单掺杂样品;降解机理可能与紫外光源有所不同。     

光催化型TiO2溶胶的制备和分析

以sol-gel工艺,采用钛酸丁酯-水-无水乙醇-盐酸体系材料,以过量水强迫前驱体充分水解,制备出具有光催化性能的氧化钛晶体溶胶。通过XRD、TEM和UV/vis测试得知,溶胶中含有原位自生长的、边长约150nm的正方形锐钛矿晶体,所以溶胶在常温下干燥后所得粉体,无需高温热处理即为锐钛矿晶型;溶胶中晶体的禁带宽度为3.58eV,具有较强的光催化性,所以溶胶(而非常见的粉体或者薄膜)在紫外光照下可使罗丹明B褪色。     

TiO_2(Ag)纳米半导体薄膜的制备及其光催化性能

对热解Ｔｉ（ＯＣ４Ｈ９）４＋ＡｇＮＯ３溶胶制备的ＴｉＯ２（Ａｇ）纳米半导体薄膜光催化特性与其结构的关系进行了研究。薄膜对二卡基砜的光催化降解结果表明,热解温度显著影响薄膜的光催化作用,这与ＴｉＯ２微粒的长大和晶相转变有关;适量的Ａｇ作活性剂可以显著改善薄膜的光催化性能。     

溶胶半导化工艺制备（Sr,Pb）TiO3系热敏电阻材料

用溶胶－凝胶法制取了钇（Ｙ）掺杂剂溶胶。利用Ｙ溶胶添加剂对钛酸锶铅Ｖ型正温度系数材料进行了半导化。为便于比较,制备了具有不同含量Ｙ溶胶添加剂及Ｙ２Ｏ３固相氧化物的（Ｓｒ０．５,Ｐｂ０．５）ＴｉＯ３样品。实验结果表明,Ｙ溶胶作为半导化添加剂优于Ｙ２Ｏ３固相氧化物,它能改善（Ｓｒ,Ｐｂ）ＴｉＯ３系陶瓷的各项性能。通过Ｙ溶胶添加剂所制备的（Ｓｒ０．５,Ｐｂ０．５）ＴｉＯ３样品的最小电阻率为２．９０×１０２Ω·ｃｍ,其Ｙ溶胶引入量ｒ（Ｙ）为０．４５％。     

PZT铁电薄膜的掺杂改性

用溶胶－凝胶方法制备了掺高价离子钇及过量Ｐｂ的ＰＺＴ铁电薄膜。探讨了添加剂对ＰＺＴ铁电薄膜的结构和电特性的影响。实验表明，过量ｒ（Ｐｂ）６％或掺高价离子ｒ（Ｙ）３％能较大地改善ＰＺＴ铁电薄膜的电性能。     

（Pb,La）TiO3铁电薄膜的制备及热释电性能研究

讨论了ＰＬＴ１５铁电薄膜的溶胶－凝胶制备技术,及ＰＬＴ薄膜的结构和电性能研究。结果表明,在Ｓｉ基片上成功地生长出钙钛矿型结构多晶铁电薄膜,在（１１１）Ｐｔ／Ｔｉ／ＳｉＯ２／Ｓｉ上外延生长出（１１１）ＰＬＴ１５铁电薄膜。溶胶－凝胶制备的ＰＬＴ１５铁电薄膜具有优良的热释电性能,其热释电系数ｐ为５．２５×１０－８Ｃｃｍ－２Ｋ－１,电压响应率优值ＦＶ达到０．７８×１０－１０Ｃｃｍ／Ｊ,探测率优值Ｆｍ为１．１３×１０－８Ｃｃｍ／Ｊ,适于制备热释电红外探测器     

Electrooptical Properties of TiO2 Doped with Gold Nanoparticles

Semiconductors - In this work, a versatile method to increase the optical response of oxide nanostructures is described. Thin TiO2 films with buried gold nanoparticles (TiO2-AuNP) were synthesized...     

PANI/TiO2和PANI/TiO2/HCSA纳米复合材料的光电性能

采用原位聚合的方法制备了PANI/TiO2纳米复合材料,用樟脑磺酸掺杂PANI/TiO2(EB)得到纳米复合膜.使用红外光谱、紫外光谱、荧光光谱及透射电镜探讨了复合材料的光电性能.     

控制铅挥发制备钛酸锶铅半导体陶瓷

在 Y 掺杂的钛酸锶铅中,分别添加过量 PbO、SiO_2、ZrO_2制备之半导体陶瓷样品,在居里点(约 120℃)以上具有强的 PTC 效应,升阻比接近 5 个数量级。其中,SiO_2或 ZrO_2增强了居里点以下的 NTC 效应,降阻比可达 1个数量级;而少量 PbO 则降低了陶瓷的室温电阻率和 NTC 效应。通过热处理可以使热敏特性由 PTC 型向 NTC-PTC复合型转变,表明 NTC 效应与铅含量变化密切相关,控制铅挥发能获得不同热敏特性的钛酸锶铅半导体陶瓷。     

TiO_2纳米粉体的制备工艺研究进展

综述了制备TiO2纳米粉体的各种方法,评述了金属醇盐水解法、水热晶化法、溶胶-凝胶法、均匀沉淀法和液相一步合成法制备工艺及特点,并指出液相一步合成法是在常压低温条件下,在液相中就可制得TiO2纳米粉体的工艺简单、适宜大规模工业化生产的最具潜力的一种制备工艺。     

Heteroatom‐Modulated Switching of Photocatalytic Hydrogen and Oxygen Evolution Preferences of Anatase TiO2 Microspheres

Understanding and manipulating the two half‐reactions of photoinduced electron reduction and hole oxidation are key to designing and constructing efficient photocatalysts. Here, how the spatial distribution of the heteroatom modulates photocatalytic reduction (hydrogen evolution) and oxidation (oxygen evolution) reaction preferences is investigated by moving boron from the core to the shell of an anatase TiO₂ microsphere along [001] via thermal diffusion control. The preference towards photocatalytic hydrogen and oxygen producing reactions from splitting water can be switched by creating a shell with an interstitial B^σ+ (σ ≤ 3) gradient in the TiO₂ microsphere. This switching stems from the downward shift of electronic band edges of the shell by a band bending effect that originates from the extra electrons coming from the interstitial B^σ+. These results create new opportunities for designing and constructing efficient photocatalysts by spatial heteroatom engineering.     

Photocatalytic activity of hydrogen production from water over TiO2 with different crystal structures

In this work, the anatase and rutile TiO₂ of single crystal structure are prepared by a facile hydrolysis method. The obtained samples are studied via various characterizations, and compared with different commercial TiO₂ (P25, ST-21, ST-31), which have mixed structures, to investigate the photocatalytic performance from water splitting. The experimental results show that the photocatalytic activity of samples depends on the surface properties and particle sizes. Moreover, compared with the TiO₂ of single crystal structure, P25 and ST-21 mixed crystal structures show superior photocatalytic hydrogen production from water splitting. According to experimental results, the possible photocatalytic mechanism of TiO₂ with mixed crystal structure is proposed.     

Harvesting Lost Photons: Plasmon and Upconversion Enhanced Broadband Photocatalytic Activity in Core@Shell Microspheres Based on Lanthanide‐Doped NaYF4, TiO2, and Au

Efficiently harvesting solar energy for photocatalysis remains very challenging. Rational design of architectures by combining nanocomponents of radically different properties, for example, plasmonic, upconversion, and photocatalytic properties, offers a promising route to improve solar energy utilization. Herein, the synthesis of novel, plasmonic Au nanoparticle decorated NaYF₄:Yb³⁺, Er³⁺, Tm³⁺‐core@porous‐TiO₂‐shell microspheres is reported. They exhibit high surface area, good stability, broadband absorption from ultraviolet to near infrared, and excellent photocatalytic activity, significantly better than the benchmark P25 TiO₂. The enhanced activity is attributed to synergistic effects from nanocomponents arranged into the nanostructured architecture in such a way that favors the efficient charge/energy transfer among nanocomponents and largely reduced charge recombination. Optical and energy‐transfer properties are modeled theoretically to support our interpretations of catalytic mechanisms. In addition to yielding novel materials and interesting properties, the current work provides physical insights that can contribute to the future development of plasmon‐enhanced broadband catalysts.     

TiO2薄膜制备及其氧敏特性

采用直流磁控溅射法制备TiO2薄膜，在不同温度下对薄膜进行退火，研究了薄膜晶体结构随退火温度的转化情况．对TiO2薄膜氧敏器件特性进行了测试，结果表明，在400℃下灵敏度随氧分压增加最快，并且在400℃具有最高的灵敏度．得到的激活能为0.41eV，并对TiO2薄膜氧敏器件的氧敏可逆性进行了讨论．