钼网衬底上大面积硅纳米线的制备及其光催化性能研究

硅纳米材料广泛应用于光功能导向的各个领域,发展针对光功能应用及一维硅纳米结构的规模化可控制备方法,实现硅纳米结构的宏量制备,将为硅纳米结构的应用提供材料保障。本文采用简单的化学气相沉积法成功地在Mo网衬底上制备了大面积的硅纳米线(SiNWs),并通过扫描电子显微镜、透射电子显微镜、X射线粉末衍射仪、拉曼光谱仪,对制备的SiNWs进行了详细的研究。通过在低功率紫外光照射下SiNWs对罗丹明B和甲基蓝的光降解能力的研究,发现在Mo网衬底上生长的SiNWs对于有机染料具有很好的降解能力。     

The coating of conducting copolymer on coordination polymer nanorod: A visible light active p-n heterojunction photocatalyst for H2 production

A visible light active p-n heterojunction photocatalyst was synthesized successfully through in-situ chemical oxidation copolymerization of aniline (ANI) and diphenylamine-4-sulfonate (DPAS) with the existence of coordination polymer nanorod (CPNR) under initiation of ammonium persulfate (APS). Compared with neat coordination polymer nanorod, the resulted p-n heterojunction photocatalyst exhibits higher H₂ generationrate under visible light irradiation. In this heterojunction photocatalyst, as a p-type semiconductor possessing suitable energy levels with coordination polymer nanorod, poly-(aniline-co-N-(4-sulfophenyl)-aniline) (PAPSA) forms p-n heterojunction with n-type coordination polymer nanorod, the inner electric field of p-n heterojunction accelerates the separation of electrons and holes, which enhances H₂ production performance. Furthermore, the influence of concentration ratio between DPAS and ANI on photocatalytic property of the p-n heterojunction photocatalyst was discussed and a reasonable condition to fabricate photocatalyst with high H₂ generationrate had been obtained. During photocatalytic water splitting H₂ generation, the p-n heterojunction photocatalyst exhibited outstanding stability.     

Synergetic effects of hydrophilic surface modification and N-doping for visible light response on photocatalytic activity of TiO2

We made attempts to improve photocatalytic activity of TiO₂ nanoparticles under visible light exposure by combining additional treatments. N-doping of TiO₂ by ammonia gas treatment increased absorbance of visible light. By coating thin film of polydimethylsiloxane, and subsequently vacuum-annealing, TiO₂ surface became more hydrophilic, thereby enhancing photocatalytic activity of TiO₂. These two treatments were combined for the first time in this work and photocatalytic activity under visible light irradiation exceeded sum of individual effects of N-doping and hydrophilic modification.     

CuAPTPP-TDI-TiO2光催化微球的合成及其光催化性能 (cited: 1)

采用Adler法合成了5-(4-氨基苯基)-10,15,20-三苯基卟啉铜配合物(CuAPTPP),通过甲苯二异氰酸酯(TDI)的桥联作用对TiO₂微球进行表面修饰,使TDI分子中的两个活性TDI基团分别与TiO₂表面的羟基和CuAPTPP的氨基反应,将CuAPTPP敏化剂分子以化学键合的方式固定在TiO₂表面,形成光催化微球CuAPTPP-TDI-TiO₂．通过FT-IR、XRD、SEM、EA、UV-Vis和DRS等测试手段对CuAPTPP-TDI-TiO₂进行结构表征．讨论了桥联分子TDI修饰量对光催化微球性能的影响,确定了TDI与TiO₂的最佳摩尔比．以亚甲基蓝(MB)为降解对象,考察了CuAPTPP-TDI-TiO₂微球的可见光催化性能．结果表明,桥联分子TDI在CuAPTPP与TiO₂微球表面形成了牢固的化学键,复合微球在150 W氙灯辐照下降解10 mg/LMB溶液,120 min降解率可达98.7%,其降解率过程服从一级动力学规律,测得降解速率常数为5.1×10^-2 min^-1,半衰期为11.3 min．催化微球在回收4次的条件下,对MB的降解率仍保持在90%以上．     

碳点修饰多孔ZnO纳米棒增强光催化性能

Porous ZnO nanorods that displayed excellent photocatalytic degradation of organic pollutants (RhB and phenol) were prepared via a solvent thermal method followed by surface modification with carbon dots (C-dots) using a deposition method. The photocatalysts were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible (UV-Vis) spectroscopy. The degradation of the organic pollutants using the nanorods was tested under Xe-light illumination and was enhanced following C-dot modification. Nanorods that were modified by the C-dots at a mass fraction of 1.2% (CZn1.2) exhibited the highest photocatalytic activity for the degradation of RhB, which was 2.5 times of the pure porous ZnO nanorods. Additionally, the modified nanorods with strangely oxidation ability could catalyze the degradation of phenol by open-rings reaction under Xe-light illumination. The improved photocatalytic activity was attributed to the effective separation of the photogenerated electrons and holes, in which the C-dots served as the receptor of the photogenerated electrons.     

双醇诱导自组装制备多级蛋壳结构TiO2材料及其光催化性能研究

采用双醇诱导自组装的方法可控合成了纳米片、实心球、核壳球、蛋壳球和空心球Ti02．利用SEM、TEM、XRD、UV-Vis等表征手段,探索了一元醇羟基的活泼性及丙三醇的三羟基结构在形成多级结构TiO2中的作用．丙三醇和一元醇的比例及醇热时间可控制TiO2的自组装过程而影响材料的形貌结构．同时光催化降解苯酚实验表明,具有多级结构的蛋壳球TiO2显示高活性,归因于光吸收增强．     

具有高活性宽光谱响应的新型光催化材料

以二氧化钛为代表的传统光催化材料只能利用短波长的紫外光,太阳光利用率和量子效率低,其广泛应用受到极大限制．针对这一问题,近年来我们开展了一系列具有高活性和（或）宽光谱响应（包括紫外及可见光）的新型纳米光催化材料的研究．本文简要总结了相应工作的进展,并对可能影响光催化材料的活性和光谱响应的相关因素进行了探讨．     

Photo-electrochemical water splitting system with three-layer n-type organic semiconductor film as photoanode under visible irradiation

A three-layer structure of n-type organic semiconductors(PTCDA/PTCDA:PCBM/PCBM) is successfully identified as photoanode for photoelectrochemical water oxidation during the overall splitting of water into hydrogen/oxygen in a nearly stoichiometric ratio(H2:O2=2:1) under visible irradiation(λ > 420 nm).A possible charge separation mechanism under visible light illumination was also proposed.     

Preparation, characterization of Mo, Ag-loaded BiVO4 and comparison of their degradation of methylene blue

Two types of metal-loaded visible-light-driven photocatalysts,Mo-BiVO4and Ag-BiVO4,were synthesized by wet impregnation method.Material poperties were characterized by UV-vis diffuse reflectance spectroscopy,X-ray diffraction,field emission scanning electron microscopy,X-ray photoelectron spectroscopy and low temperature nitrogen adsorption-desorption.Photocatalytic activity of the obtained materials was investigated through degrading methylene blue(MB) solution under visible-light irradiation.The results reveal that both metal loaded-BiVO4catalysts have monoclinic scheelite structure.Mo and Ag exist as oxides on the surface of the particles.The changes of absorption in visible-light region,band gap(E g) and specific surface area(A BET) caused by loading Ag are more obvious than those caused by loading Mo.But the isoelectric point of Ag-BiVO4decreases less than that of Mo-BiVO4does.Both catalysts show higher photocatalytic activity than pure BiVO4,resulting in the significantly improved efficiency of degradation of MB.And the degradation efficiency of these two metal-loaded BiVO4photocatalysts is similar to each other.However,mechanisms of such enhancement are different.The decrease of isoelectric point helps Mo-BiVO4improve the degradation efficiency.As for Ag-BiVO4,the augmentation of absorption in visible-light region as well as the abatement of E g plays more important roles.     

CuAlO2的合成及其复合催化剂的光催化性能

以硝酸铜和硝酸铝为原料,草酸为铜离子的沉淀剂,半湿法制得前驱体,再于氮气气氛下热处理形成了铜铁矿结构的CuAlO2。对样品进行热失重(TG),X射线衍射(XRD),紫外-可见漫反射(UV-Vis-DR)及透射电镜(TEM)表征分析,探讨了CuAlO2的形成过程。结果显示,随着热处理温度的升高,含铜物质经历了由CuO、Cu2O到CuAl2O4,再到CuAlO2的变化历程;制得的CuAlO2晶体结晶完整性较好,直接禁带宽度为3.1 eV左右。用沉淀复合的方法制备出了n-p异质复合型光催化剂WO3-CuAlO2、TiO2-CuAlO2和ZnO-CuAlO2,对复合催化剂进行了XRD和TEM表征分析,并测试了复合催化剂的光催化活性。结果表明,上述催化剂均由两种物相复合而成,且在紫外光的照射下均可分解纯水放出氢气。