共查询到19条相似文献,搜索用时 62 毫秒
1.
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
2.
综述复合纳米TiO2光催化净化大气环保涂料研究进展,着重介绍该涂料制备工艺中纳米TiO2改性研究和纳米粉体在涂料中的分散和分散稳定性的研究近况。 相似文献
3.
选择溶胶-凝胶方法制作纳米TiO2,且将纳米TiO2负载于分子筛上面。实验结果表明,与非负载光催化剂相比,负载光催化剂具体性能更优。针对目标物实行降解时,最优条件为,pH值是4.7,H2O2最初的物质的量浓度是25 mmol/L,甲基橙最初的质量浓度是20 mg/L,增加量是2 g;温度升高有利于降解;随应用频次提升,催化剂具体活性渐渐下降。 相似文献
4.
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
5.
6.
7.
8.
9.
10.
为了提高TiO_2光催化剂对水体有机污染物的降解能力,将松子壳基活性炭作为载体负载TiO_2,研究载体比表面积、载体与TiO_2的复合比例以及煅烧温度对复合光催化剂降解水体有机污染物亚甲基蓝的影响。通过BET,XRD,FTIR和SEM分析方法对复合光催化剂的比表面积、晶体结构、有机官能团和表面形貌进行了表征。研究结果表明:适当的增加载体的比表面积,有利于Ti O2的负载和复合光催化剂催化活性的提高;当活化水量为1.5 mL/min时,在充分的水蒸气活化反应下,松子壳炭可制备成比表面积为634.65 m~2/g的活性炭,使其负载TiO_2后具有较好的亚甲基蓝吸附作用和光降解作用;当TiO_2与活性炭的质量比为0.8∶1时,复合光催化剂的催化效果较好;当煅烧温度为450℃时,复合光催化剂具有较优的催化效果,降解率可达77.10%。 相似文献
11.
Li‐Fang Wei Xian‐Jun Zheng Zhi‐Hong Zhang Yong‐Jie Wei Bing Xie Ming‐Bao Wei Xiao‐Li Sun 《国际能源研究杂志》2012,36(1):75-86
The propionic acid (HPr) is one of the main by‐products during fermentative H2 process. To efficiently convert HPr to H2 gas, photocatalytic H2 production from HPr solution with the use of Pt/TiO2 photocatalyst under ultraviolet light has been studied in this research. The Pt/TiO2 photocatalyst has been prepared by the sol–gel method and further characterized by X‐ray diffraction, TEM and XPS. Effects of Pt loading amount, HPr concentration, initial pH value on photocatalytic H2 production have been investigated in detail. From practical point of view, the H2 evolution from HPr solution under UV irradiation for prolonged time has been studied as well. The Langmuir model can be able to describe the relationship between HPr concentration with the maximum rate of H2 production. The apparent quantum efficiency and apparent energy conversion efficiency are found to 1.65 and 0.72%, respectively. To better understand the photocatalytic H2 process over Pt/TiO2, a possible mechanism for the degradation of HPr has been proposed as well. Based on our results, an efficient route for hydrogen production from renewable biomass can be established by coupling biological H2 production process with photocatalytic H2 production process. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
12.
Photocatalytic hydrogen production from glycerol–water mixture over Pt‐N‐TiO2 nanotube photocatalyst
The effects of several modifications on TiO2 P25 in producing hydrogen from glycerol–water mixture have been investigated. Prior to further modification, TiO2 underwent hydrothermal treatment at 130°C for several hours to obtain nanotube shape. TiO2 nanotubes (TiNT) was then doped with platinum (Pt) and nitrogen (N) by employing photo‐deposition and impregnation method, respectively. SEM and XRD results showed that Pt‐N‐TiNT was successfully obtained as pure anatase crystal structure. The effects of glycerol content to photocatalytic activity of hydrogen production have also been studied, result in 50%v of glycerol as the optimum concentration correspond to the stoichiometric volume ratio of glycerol reforming. The results of photo‐production test showed that TiNT (nanotube) could enhance hydrogen generation by two times compared with unmodified P25 (nanoparticle). Meanwhile, simultaneous modification of TiNT by Pt and N dopants (Pt‐N‐TiNT) lead to activity improvement up to 13 times compared with P25. The output of this study may contribute toward finding an alternative pathway to produce H2 from renewable resources. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
13.
Nemanja Banić Jugoslav Krstić Stevan Stojadinović Anđela Brnović Aleksandar Djordjevic Biljana Abramović 《国际能源研究杂志》2020,44(11):8951-8963
Five NiO/TiO2 materials with a different mass ratiо оf NiO tо TiO2 (3.3, 6.7, 16.3, 23.7, and 36.8%) were synthesized by wet impregnation process and characterized by DR UV-vis, scanning electrоn micrоscоpe, transmissiоn electrоn micrоscоpy, X-ray diffractiоn methоd, N2 physisorption, and temperature-programmed reduction. The characterizatiоn confirmed the existence of nano-sized cubic NiO on the commercial TiО2. The оbserved interactiоn between TiO2 and NiО phases confirmed that the оbtained material dоes nоt constitute a physical mixture оf twо species. The photocatalytic hydrоgen generatiоn efficiency [mоnitored by gas chromatography–thermal conductivity detector (GC-TCD)] of these materials from methanol-water mixtures under simulated solar radiation and artificial UV radiation was investigated. For some synthesized NiO/TiO2 materials, higher photocatalytic efficiency was found compared with the commercial TiO2 Degussa P25 catalyst. Also, the obtained results showed that 0.125 g L−1 of 6.7%NiO/TiO2 and 5% (v/v) of methanol were the optimal operating parameters. Furthermоre, fоr the mоst efficient phоtоcatalytic system under the influence оf simulated solar radiation, a 1.8 times higher hydrоgen prоduction rate was achieved cоmpared tо that under the influence оf artificial UV radiatiоn. 相似文献
14.
Cu particles have been deposited on TiO2 by incipient-wetness impregnation followed by low-temperature (400°C) calcination/reduction, and the metallization process leads to significant enhancement in photocatalytic activity of TiO2 for H2 production from aqueous methanol solution. The activity exhibits up to 10-fold enhancement at the optimum loading of 1.2 wt% Cu. Spectroscopic studies indicated that the Cu particles were oxidized during reaction to have a valence lower those of thermally oxidized particles, which showed inferior activities. Dissolution of Cu ion in TiO2 lattice, in contrast, resulted in reduction in photocatalytic activity. 相似文献
15.
Sabina Ait ABDELKADER Zhenpeng CUI Abdelghani LAACHACHI Christophe COLBEAU-JUSTIN Mohamed Nawfal GHAZZAL 《Frontiers in Energy》2021,15(3):732
In this study, the electronic and photocatalytic properties of core-shell heterojunctions photocatalysts with reversible configuration of TiO2 and Bi2O3 layers were studied. The core-shell nanostructure, obtained by efficient control of the sol-gel polymerization and impregnation method of variable precursors of semiconductors, makes it possible to study selectively the role of the interfacial charge transfer in each configuration. The morphological, optical, and chemical composition of the core-shell nanostructures were characterized by high-resolution transmission electron microscopy, UV-visible spectroscopy and X-ray photoelectron spectroscopy. The results show the formation of homogenous TiO2 anatase and Bi2O3 layers with a thickness of around 10 and 8 nm, respectively. The interfacial charge carrier dynamic was tracked using time resolved microwave conductivity and transition photocurrent density. The charge transfer, their density, and lifetime were found to rely on the layout layers in the core-shell nanostructure. In optimal core-shell design, Bi2O3 collects holes from TiO2, leaving electrons free to react and increase by 5 times the photocatalytic efficiency toward H2 generation. This study provides new insight into the importance of the design and elaboration of optimal heterojunction based on the photocatalyst system to improve the photocatalytic activity. 相似文献
16.
《International Journal of Hydrogen Energy》2020,45(13):7764-7778
Titanium dioxide remains a benchmark photocatalyst with high stability, low cost, and less toxicity, but it is active only under UV light; thus, in practical applications using visible light, its catalytic reactions are stalled. To enhance its catalytic activity under visible light, non-metal/codoped TiO2 structures are being studied. These structures improve the photocatalytic activity of TiO2 in visible light by reducing its energy bandgap. This might be useful in wastewater treatment for the photocatalytic degradation of organic contaminants under visible and UV light irradiation. In this intensive review, we describe recent developments in TiO2 nanostructured materials for visible-light driven photocatalysis, such as (i) mechanistic studies on photo-induced charge separation to understand the photocatalytic activity and (ii) synthesis of non-metal doped/codoped TiO2 and TiO2 nanostructured hybrid photocatalysts. Furthermore, the effects of various parameters on their photocatalytic efficiency, photodegradation of various organic contaminants present in wastewater, and photocatalytic disinfection are delineated. 相似文献
17.
Pure Na0.23TiO2 nanofibers were fabricated by a two‐step hydrothermal method after a series of experiments. Na0.23TiO2 is a direct bandgap semiconductor and exhibits a strong photodegradative ability for RhB, which is difficult to be degraded. The photodegradative activity is much enhanced after loaded noble metal Au or Ag nanoparticles on Na0.23TiO2 nanofibers by a chemical bath deposition method. Hot electrons are generated in metal nanoparticles through a localized surface plasmon (LSP) process under light illumination and then diffuse to a semiconductor and reduce the surface potential, which is detected directly by a scanning Kelvin probe microscopy (SKPM). The high electromagnetic field induced by the LSP resonance and strong coupling between noble metal and Na0.23TiO2 are beneficial for the utilization of visible light, electron produce, charge transportation, and separation, as a result, promoting the activity of semiconductor‐based photocatalysts. This work supplies an effective method to directly probe the surface plasmon and highlights the application of Na0.23TiO2 in photocatalysis. 相似文献
18.
采用溶胶—凝胶法制备Ce掺杂TiO2光催化剂,借助XRD、HRTEM对其进行表征,分析了Ce含量、煅烧温度等因素对光催化降解偶氮废水活性的影响。结果表明,铈掺杂在提高了TiO2光催化剂催化活性的同时也抑制了相转变。当Ce的掺杂量为3%时,对偶氮废水的处理率可高达92.3%。 相似文献
19.
Prof. Dr. M. Meliß Dr. A. Neskakis Dipl.-Phys. J. Plettner-Marliani Dipl.-Ing. C. Lange Dr.-Ing. A. Hvelmann Dipl.-Ing. J. Schumacher 《Renewable Energy》1998,14(1-4)
The providing of pure water for human needs and irrigation is one of the most important problems of many countries in hot climate. Moreover waste water is not purified at all or insufficiently. Purified waste water could be used by mankind e.g. for irrigation in order to establish a closed water circulation. Excellent solar- and wind conditions in the regions with hot climate suggest an energy supply with renewable energies for many applications. The feasibility of the combination of purification plants with a renewable energy supply is investigated. The investigations are carried out as follows: first of all the problematic of water and energy supply in developing countries is described. Then a general analysis of the system structure in view of the energy supply is made. A waste water treatment plant (WWTP) with a low energy demand which is adapted to a renewable power supply is designed. To present the investigations more clearly they refer to data representative for Jordan. 相似文献