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《International Journal of Hydrogen Energy》1999,24(10):957-963
Mixed semiconductor (CdS–ZnS)–TiO2(1 : 1 : 1) mixture system over different supports like MgO, CaO, γ-Al2O3, SiO2 and modified MgO and CaO, have been prepared, characterized and tested for H2 production in a S2−⧸SO2−3 mixture solution. (CdS–ZnS)–TiO2(D) over MgO support wherein the TiO2 taken is from Degussa (D) sample gives 206.7 μmol⧸h of H2 production and this catalyst sustain the H2 production rate for longer durations. Dopants like Li2O, Cs2O or K2O make MgO and CaO supports act like super basic oxide when they are doped and in turn increase the photocatalytic activity. The (CdS–ZnS)–TiO2(I) system wherein the TiO2 taken from Titanium Isopropoxide, supported on 20 wt% Li2O doped CaO is found to give 209.8 μmol⧸h rate of H2 production. Characterization studies like UV-Visible spectra, X-ray Diffraction spectra and Scanning Electron Microscope photographs were taken for all the catalysts and the data generated over these samples is evaluated. A scheme of H2S photocatalytic decomposition of ZnCdS–TiO2(D⧸I) over different supports in the presence of S2−⧸SO2−3 substrate, is proposed indicating the formation of thiosulfate cycle at this heterojunction. © 1999 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved. 相似文献
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综述近年来关于纳米TiO2光催化剂的改性研究进展,详细叙述针对该催化剂的各种改性方法的原理,制备方法及目前的研究进展,展望该领域的研究方向.提出以共掺杂为基础的改性、可重复利用的催化剂以及纳米TiO2薄膜制备和大型反应器的设计是研究的主要课题. 相似文献
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TiO2纳晶多孔薄膜固态太阳电池 总被引:7,自引:4,他引:7
该文报导了用交联聚醚聚氨酯 (PEU)凝胶网络型高分子和以聚硅氧烷为基础含有聚氧化乙烯 (PEO)内增塑链的凝胶网络高分子为电解质的TiO2 纳晶固态太阳电池的制备及性能。在所研究的 3种固体电解质 (SPE 1,SPE 2及SPE 3)中 ,具有低交联度、高盐 (KI)含量的凝胶网络型高分子电解质 (SPE 2 ) ,其离子导电性最佳 ,可以与液体电解质相比 (σ =2 1× 10 -3S·cm-1) ,由此构成的固态电池具有最好的光电化学性能。改进凝胶网络高分子电解质的结构组成以及优化TiO2 纳晶多孔薄膜 /高分子凝胶的界面可以进一步改善固态电池的性能 ,提高转换效率。 相似文献
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掺Ag复合纳米TiO2光催化性能 总被引:1,自引:0,他引:1
通过溶胶-凝胶法和光还原法制备掺Ag复合纳米TiO2.用XRD表征了TiO2的晶体形态.以典型偶氮结构的甲基橙水溶液为模拟对象,研究掺Ag复合纳米TiO2光催化性能.实验结果表明,TiO2悬浮体系中甲基橙的光催化降解符合Langmuir动力学规律.根据动力学计算,掺Ag复合TiO2和单纯TiO2对甲基橙的降解速率常数分别为27.34mg/(L·h)和14.42mg/(L·H),光催化的活性提高了近2倍.因此有望通过这一技术制备出比单纯TiO2更好的光催化剂. 相似文献
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Ho掺杂纳米TiO2光催化性能研究 总被引:1,自引:0,他引:1
以钛酸四正丁酯为原料,采用溶胶-凝胶法制备了纯的和Ho掺杂的TiO_2纳米粒子,对样品进行了TG- DTA、XRD和UV-Vis吸收光谱分析,并以甲基橙的光脱色反应考察了样品的光催化性能。发现Ho的掺杂抑制了TiO_2粒径的长大,细化了晶粒;Ho掺入到TiO_2的晶格中,引起了晶格的畸变和膨胀;Ho的掺杂使TiO_2的吸收带边发生微小的蓝移,且在450nm和540nm光区附近产生吸收;适量Ho的掺杂可提高TiO_2的光催化性能,紫外光照下,Ho的掺杂量为0.3%时,光催化性能最佳;可见光下(波长>420nm),Ho掺杂的TiO_2呈现光催化活性,210min内甲基橙的脱色率可达21.6%。 相似文献
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将TiO2分别与两类活性炭吸附材料相结合,分析不同活性炭吸附作用对污染物甲醛的光催化去除影响.实验结果表明,以活性炭颗粒为载体负载TiO2催化剂形成的催化剂膜对污染物的去除效率低于以蜂窝活性炭网为载体负载催化剂形成的催化剂膜;同以玻璃为载体的催化剂膜相比,以活性炭材料为载体的催化剂膜对污染物的去除同样表现为传质控制过程和光催化控制过程,且随流速增加,光催化反应从传质控制向光催化控制过渡的转换点提前,在低污染物浓度条件下,污染物的光催化去除受污染物传质和驻留时间控制,且驻留时间的影响是主要的,随着驻留时间的增加,污染物的去除率提高. 相似文献
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Subas Muduli Onkar Game Vivek Dhas K. Vijayamohanan K.A. Bogle N. Valanoor Satishchandra B. Ogale 《Solar Energy》2012,86(5):1428-1434
Anatase TiO2 nanoparticles dressed with gold nanoparticles were synthesized by hydrothermal process by using mixed precursor and controlled conditions. Diffused Reflectance Spectra (DRS) reveal that in addition to the expected TiO2 interband absorption below 360 nm gold surface plasmon feature occurs near 564 nm. It is shown that the dye sensitized solar cells made using TiO2–Au plasmonic nanocomposite yield superior performance with conversion efficiency (CE) of ~6% (no light harvesting), current density (JSC) of ~13.2 mA/cm2, open circuit voltage (Voc) of ~0.74 V and fill factor (FF) 0.61; considerably better than that with only TiO2 nanoparticles (CE ~ 5%, JSC ~ 12.6 mA/cm2, Voc ~ 0.70 V, FF ~ 0.56). 相似文献
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活性炭与TiO2相结合去除室内污染物甲醛的实验研究(Ⅰ) 总被引:2,自引:1,他引:1
将光催化技术与活性炭吸附技术相结合,利用活性炭吸附功能,强化污染物向催化剂表面的传质,在催化剂表面形成局部高浓度,提高室内低污染物浓度条件下的光催化去除效率.实验结果表明,活性炭吸附材料存在吸附饱和,而将活性炭材料与光催化剂相结合,一方面可以提高污染物光催化去除效率,另一方面,污染物的光催化作用可以延缓活性炭材料的吸附饱和,延长活性炭材料的使用寿命;同时在活性炭材料上负载催化剂则存在着最佳的催化剂负载量.这两种捌术相结合形成的催化剂膜,既具有一定的牢固性又有一定活性.本研究结果为光催化技术的应用提供了理论支持. 相似文献
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《International Journal of Hydrogen Energy》2020,45(40):20605-20619
This paper studies the catalytic activity of Pt deposited onto Nb-doped titania supports toward the hydrogen evolution reaction (HER). New catalysts based on Nb-doped TiO2 nanoparticles (nNb-TiO2) and Nb-doped TiO2 nanotubes (nNb-TNTs), with n in the range 3–10 at % (Nb + Ti), were synthesized. The specific surface areas of nNb-TNTs were 250–300 m2g-1, about three times higher than those of nNb-TiO2. X-ray diffraction showed the Nb incorporation into the TiO2 lattice with its consequent lattice expansion. The X-ray photoelectron spectra of Pt deposited onto Nb-doped titania revealed a negative charge accumulation on Pt, thus denoting strong metal-support interaction. The electrochemical characterization in acidic media showed that Pt supported on nNb-TiO2 and nNb-TNTs presented better activity toward the HER than that of Pt deposited onto the un-doped supports and commercial Pt on carbon. The best performance was obtained with a small Nb doping of 3 at %. 相似文献
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《International Journal of Hydrogen Energy》2020,45(7):4152-4160
Hydrogen is the eco friendly fuel that can supplement the requirements for power generation.Nickel based nano composites attracted much researchers due to its wide applications in various fields viz., solar cells, capacitors, batteries and aerospace engineering. NiO-Pr2O3/TiO2 and NiO/TiO2 nano composites have high catalytic activity for producer gas conversion by the process of decomposition of tar molecules generated during biomass gasification. In this work, we have investigated the growth of NiO-Pr2O3/TiO2 and NiO/TiO2 nano composites by the method of deposition precipitation technique. Structural investigation represented that the TiO2 possess cubic structure with preferential orientation along (111) plane. Morphological features denoted the formation of non agglomerated grains. The sizes of the grains with nanometer scale have been identified by transmission electron microscopy. The surface area and porosity nature of the nano composites has been analyzed using Branauer Elmer Teller and Barrett-Joyner - Halenda techniques, respectively. The estimated value of surface area is found to be 110 and 81 m2g-1 for NiO-Pr2O3/TiO2 and NiO/TiO2 nano composites, respectively. The increment in the content of hydrogen present in the producer gas has been investigated using catalytic tar cracking method. The NiO-Pr2O3/TiO2 nano composite exhibited better tar cracking with higher content of hydrogen conversion than NiO/TiO2. 相似文献
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TiO2-xNx光催化剂的制备及其活性研究 总被引:1,自引:1,他引:0
在sol-gel法制备TiO2的过程中引入氨水进行水解,制备了具有可见光活性的TiO2-xNx催化剂,采用UV-Vis、BET、XPS等手段进行表征,以苯甲酸为模型污染物,氙灯为模拟太阳光源,评估了催化可见光催化活性.结果表明,随着焙烧温度的升高,TiO2-xNx的吸光特性增加,当温度超过350%后TiO2-xNx中的氮会在高温下被氧化掉,其吸光特性又降低;此时TiO2-xNx的吸收阈值为422nm,对应的禁带宽度为2.9eV;孔径分布在2.5~8.2nm之间,BET比表面积为139.3m2/g;经计算其x=0.0282,即TiO2-xNx可表示为Ti1.9718N0.0282;在入射波长分别为500nm和600nm时,TiO2-xNx对苯甲酸的去除率分别为6.5%和4.6%,相应的矿化率为3.2%和2.5%. 相似文献
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采用水热法在FTO基板上制备Ti O2纳米线阵列,在此基础上,通过水热法采用HCl对该薄膜进行原位刻蚀。XRD结果表明刻蚀过程并未影响Ti O2纳米线阵列薄膜的结晶性。SEM结果表明刻蚀过程能有效降低纳米线之间的团聚程度,从而保证薄膜具有较大的比表面积。染料的吸附-脱附结果也表明,刻蚀后纳米线薄膜的染料负载能力提高了1倍,将制备的Ti O2纳米线阵列薄膜作为染料敏化太阳电池的光阳极进行光电性能研究,发现使用经过刻蚀处理光阳极的太阳电池比采用未刻蚀处理的光阳极薄膜的电池光电转换效率提高了6倍。 相似文献