纳米黑磷的改性及其在光催化析氢领域的应用

黑磷作为一种新型的二维材料,具有高载流子迁移率、强大的光吸收性、高比表面积以及各向异性等特点,在光催化领域表现出极强的应用潜力,如光催化析氢、光催化降解有机污染物和生物医学光热、光动力学治疗等。但黑磷存在易氧化且光生电子-空穴复合严重等问题,需要通过改性提高黑磷光催化剂的性能。本文综述了表面修饰、掺杂、复合以及构建异质结等黑磷改性方法,着重对黑磷基材料在光催化产氢领域的应用进行了详细介绍,并指出了黑磷基材料在光催化领域应用需要克服的问题并展望及前景。     

CeO2/TiO2光催化剂的制备及其可见光脱氮性能

采用溶胶-凝胶和浸渍掺杂两步法合成了CeO₂/TiO₂光催化剂,并对催化剂的理化结构进行表征分析;以吡啶-正辛烷体系为模拟油品氮源,研究了该催化剂在可见光作用下的光催化脱氮行为,并探究了光催化脱氮的最佳反应条件。 结果表明,掺杂的铈主要以CeO₂的形式存在,且增强了催化剂在可见光区的吸收;在可见光辐照150 min的条件下,铈的掺杂量质量分数为8%,所制备的CeO₂/TiO₂催化剂投入量为1.0 g/L时,模拟油品中吡啶的脱氮率高达76.45%。     

Reusable thin film photocatalyst of Fe‐doped TiO2 deposited by ECR plasma

The paper presents an improved method of depositing nanocrystalline thin films of Fe‐doped TiO₂ to be used as a reusable cyclic photocatalyst for degrading the organic pollutants. The technique of electron cyclotron resonance plasma‐enhanced chemical vapor deposition was employed with titanium tetra‐isopropoxide (C₁₂H₂₈O₄Ti) and ferrocene (C₁₀H₁₀Fe) as precursors of Ti and Fe, respectively. Optical emission spectroscopy was used to identify the reactive species, to determine the electron temperature and the ion density during deposition. The films were characterized using optical absorption and photoluminescence spectra, whereas the morphological analysis was carried out with scanning electron microscopy. Strong adhesion of the deposited films with the substrate ruled out any possibility of TiO₂ particles being leached out. It was confirmed by observing the degradation rate of the same film repeatedly. Cyclic use of the film for the catalytic reactions thus makes the process much user friendly for the water treatment. Copyright © 2014 John Wiley & Sons, Ltd.     

Fe-CuS/还原氧化石墨烯(RGO)的制备及其光催化性能

以氯化铜(CuCl_2·2H_2O)、硫脲((NH2)2CS,Tu)、1,2-丙二醇(1,2-PG)、氯化铁(FeCl_3·6H_2O)及氧化石墨烯(GO)为原料,通过溶剂热法制备了具有可见光活性的Fe-CuS/RGO复合材料。采用XRD、SEM、TEM、Raman、XPS、TG、UV-Vis等手段对产品进行了表征,并以亚甲基蓝(MB)为目标降解物对其可见光催化活性进行了研究。光催化结果表明:在汞灯(150 W)下照射140 min,CuS、CuS/RGO和Fe-CuS/RGO对MB的脱色率分别为41.2%、81.5%和90.6%。Fe-CuS/RGO对MB的降解效率较CuS/RGO和CuS有较大提升,可能原因是Fe元素有利于电荷在CuS与RGO界面间传输,降低了光生电子-空穴对的复合几率,进而提高了光催化活性。     

TiO2/AC光催化剂上气体污染物降解的反应动力学模型

 利用二氧化钛与活性炭(AC)共水热处理的方法制备了TiO2/AC复合催化剂,采用空气净化评价装置对其催化降解低浓度气体污染物丁醛的性能进行了模拟评价实验. 基于Langmuir-Hindshelwood方程和一些假设,推导了循环反应系统气体污染物降解的瞬态模型. 结果表明,该动力学模型所得数据与丁醛的模拟评价实验结果基本相符,预示着该模型能够很好地预测污染物的降解行为.     

TiO2/AC复合光催化剂对苯和丁醛的气相光催化降解机理

 利用溶胶-凝胶并水热处理法制备了TiO2光催化剂和TiO2/AC复合光催化剂,在静态光催化反应器中研究了苯和丁醛的气相吸附和光催化降解,利气相色谱分析确定了生成的中间体. 结果表明, TiO2/AC复合光催化剂比TiO2光催化剂具有较强的吸附能力和较高的光催化活性; 在TiO2和TiO2/AC上,苯(或丁醛)光催化降解产生相同的中间体,表明在两种催化剂上发生的光催化反应遵循相同的机理,进而讨论了其可能的光催化氧化途径.     

A Novel N-Doped Nanoporous Bio-Graphene Synthesized from Pistacia lentiscus Gum and Its Nanocomposite with WO3 Nanoparticles: Visible-Light-Driven Photocatalytic Activity

This paper reports the synthesis of a new nitrogen-doped porous bio-graphene (NPBG) with a specific biomorphic structure, using Pistacia lentiscus as a natural carbon source containing nitrogen that also acts as a bio-template. The obtained NPBG demonstrated the unique feature of doped nitrogen with a 3D nanoporous structure. Next, a WO₃/N-doped porous bio-graphene nanocomposite (WO₃/NPBG-NC) was synthesized, and the products were characterized using XPS, SEM, TEM, FT-IR, EDX, XRD, and Raman analyses. The presence of nitrogen doped in the structure of the bio-graphene (BG) was confirmed to be pyridinic-N and pyrrolic-N with N1 peaks at 398.3 eV and 400.5 eV, respectively. The photocatalytic degradation of the anionic azo dyes and drugs was investigated, and the results indicated that the obtained NPBG with a high surface area (151.98 m²/g), unique electronic properties, and modified surface improved the adsorption and photocatalytic properties in combination with WO₃ nanoparticles (WO₃-NPs) as an effective visible-light-driven photocatalyst. The synthesized WO₃/NPBG-NC with a surface area of 226.92 m²/g displayed lower bandgap and higher electron transfer compared with blank WO₃-NPs, leading to an increase in the photocatalytic performance through the enhancement of the separation of charge and a reduction in the recombination rate. At the optimum conditions of 0.015 g of the nanocomposite, a contact time of 15 min, and 100 mg/L of dyes, the removal percentages were 100%, 99.8%, and 98% for methyl red (MR), Congo red (CR), and methyl orange (MO), respectively. In the case of the drugs, 99% and 87% of tetracycline and acetaminophen, respectively, at a concentration of 10 mg/L, were removed after 20 min.     

Preparation and Performances of RuO2/TiO2 Films Photocatalyst Supported on Float Pearls

"RuO2/TiO2 films were deposited on float pearls (FP) by the sol-gel-dipping method. The substrates were coated with RuO2/TiO2 precursor sol, air-dried at 120 oC and further heated at 500 oC to obtain the coupled photocatalyst of RuO2/TiO2 films supported on FP (RuO2/TiO2/FP). The structure of coupled photocatalyst was characterized by SEM, XRD, and FT-IR technique, respectively. The results showed TiO2 has anatase structure and doped RuO2 was highly dispersed on the surface of TiO2 particles as amorphous. The average thickness of RuO2/TiO2 films (3 layers) on FP was determined to be about 1 1m. This study was carried out under the following conditions: volume 60 mL, initial concentration of beta-cypermethrin (BEC) 45 mg/L, pH 6.5, amount of RuO2/TiO2/PF 5 g/L, air flow rate 200 mL/min, reaction time 60 min. The degradation rates of BEC are 88.1% (125 W Hg lamp), 82.8% (8 W UV lamp), and 75.1% (8 W solar lamp), respectively. The photocatalytic degradation of BEC was experimentally demonstrated to follow the Langmuir-Hinshelwood kinetic model, and the reaction rate constant (17.5 mg/(L min)) and the adsorption constant (3.486 L/g) were determined, respectively. It was also found that the RuO2/TiO2 /FP photocatalyst has significantly the visible light photoactivity for degradation of BEC."     

TiO2光催化薄膜在陶瓷器具上抗菌效果的研究

抗菌薄膜;TiO2光催化薄膜在陶瓷器具上抗菌效果的研究     

TiO2 /wAC复合光催化剂的酸催化水解合成及表征

以TiCl4为钛源, 采用酸催化水解法合成了活性炭(AC)复合光催化剂TiO2/wA(w:AC 的质量分数, %). 通过对苯酚、甲基橙以及六价铬的光催化降解, 考察了AC 含量、反应溶液初始pH值、使用次数对TiO2/wAC光催化剂催化活性的影响,并采用重力沉降法测试了催化剂分离性能. 采用XRD、DRS、FTIR、SEM、低温液氮吸附等对光催化剂晶相结构、光谱特征、表面结构等进行了表征. 结果表明, 适宜AC 含量的TiO2/wAC(wAC=5%, 记为5AC)具有较高的光催化活性.AC 掺杂可减小TiO2粒子凝聚, 而对TiO2的晶相结构、晶粒大小以及表面性质影响不大, 对TiO2能阈结构不产生影响. TiO2与AC结合牢固, 接触界面处有Ti—O—C 键生成. TiO2/5AC 表现出高光催化活性的主要原因是, AC 所提供的适宜高浓度环境及对纳米尺寸TiO2团聚的有效抑制. TiO2/5AC的高活性, 不易失活, 易分离以及活性受pH 变化影响较小的特性,使其在实际废水处理方面具有潜在应用价值.