四磺基酞菁锌敏化TiO2的原位自组装合成及可见光光催化

采用溶胶-凝胶法与原位合成相结合的方法,合成了2,9,16,23-四磺基酞菁锌(ZnfsPc)/TiO2复合材料,用FTIR,UV-Vis,XRD,Zeta电位、荧光光谱等对复合材料进行了表征,同时对材料进行了可见光光催化反应实验.实验结果表明采用该原位自组装的方法,不仅在TiO2颗粒表面原位生成酞菁,还在TiO2表面形成化学键(-SO2-O-Ti-).有效地增强了ZnTsPc的敏化能力,使光生载流子形成有效的分离,从而大幅度地提高了复合材料的可见光光催化能力.     

纳米复合材料TiO2-ZrO2光催化降解可溶性染料的研究

采用溶胶-凝胶方法将光催化剂TiO2和ZrO2复合,再经700℃灼烧5h后获得了纳米复合光催化材料TiO2-ZrO2.该材料经XRD检测具有光催化活性良好的晶型结构.TEM测定结果显示产物的平均粒径约为20nm.通过对可溶性染料刚果红等的光催化降解实验证明,该复合材料具有较高的光催化活性.     

聚(2-甲氧基-5-辛氧基)对苯乙炔/TiO2纳米复合材料的光物理性能研究

通过原位强碱诱导下的脱氯化氢缩合聚合法制备了一系列不同纳米TiO2含量的聚(2-甲氧基-5-辛氧基)对苯乙炔/纳米二氧化钛(PMOCOPV/TiO2)光电复合材料。红外光谱和拉曼光谱证实了在纳米TiO2表面的包覆层为PMOCOPV。紫外-可见吸收光谱表明随着TiO2含量的增加PMOCOPV/TiO2纳米复合材料的吸收强度提高。高分辨透射电镜观察发现PMOCOPV/TiO2是具有核-壳结构的纳米复合粒子,直径约30 nm,其中PMOCOPV包覆层的厚度约为8~10 nm。荧光光谱研究表明,PMOCOPV/TiO2纳米复合材料的最大发射波长随着TiO2含量的增加发生红移,荧光寿命约为1 ns,且随着TiO2含量的增加荧光强度和荧光寿命得到显著提高,并通过PMOCOPV/TiO2纳米复合材料中的激子离化和电荷传输过程以及复合材料中的电势能级探讨了PMOCOPV/TiO2的荧光量子效率和荧光强度增加的机理。     

TiO2/SiO2复合材料的制备及光催化性能

通过TiCl4水解与超细石英粉制备TiO2/SiO2复合材料,红外光谱表明TiO2与SiO2发生键合作用,形成了Si-O-Ti的网络结构,XRD结果表明TiO2/SiO2复合材料为锐钛矿晶型结构,透射电镜结果表明复合粒子之间有团聚现象.以TiO2/SiO2复合材料对甲基橙进行降解,光催化120min可达到69％的降解率...     

PbSe/TiO2同轴异质结纳米管的制备及光催化性能

通过溶液法合成了PbSe/TiO2复合纳米管,并对其进行了微观形貌、晶体结构等的表征。结果表明,制得的样品是由PbSe和TiO2两种材料构成的复合材料,致密、均匀的TiO2薄膜包覆在PbSe纳米管表面。以氙灯为模拟光源,通过对甲基橙的降解研究了PbSe/TiO2复合纳米管的光催化性能。结果显示,PbSe与TiO2之间形成的异质结使PbSe/TiO2复合纳米管具有较高的光催化性能,比纯PbSe纳米管的催化降解率提高了约4.5倍。另外,对PbSe/TiO2复合纳米管光催化稳定性也进行了研究。     

RuO2/TiO2/漂珠复合光催化剂的制备及性能

"利用RuO2/TiO2前驱体溶胶,采用溶胶-凝胶-浸渍法在漂珠(FP)表面沉积RuO2/TiO2膜,经120 ℃干燥、500 ℃焙烧制备复合光催化剂RuO2/TiO2/FP,并通过SEM、XRD以及FT-IR分别对其结构进行了表征． 结果表明,RuO2/TiO2膜的平均厚度(三层)约1 1m,膜材料中TiO2主要呈现锐钛矿型结构,而RuO2是以非晶态高度分散在粒子表面．以高效氯氰菊酯杀虫剂的光催化降解为模型反应,研究了RuO2/TiO2/FP的光催化性能,探讨了影响催化剂活性的因素及采用太阳光做光源处理     

镍锰共掺杂TiO2的制备及其光催化性能研究

采用溶胶-凝胶的方法,镍、锰离子在钛酸丁酯[Ti(OBu)4]水解的条件下掺杂到TiO2中,合成了不同摩尔比的镍、锰离子共掺杂的TiO2光催化剂.通过光催化降解甲基橙实验,对所制备光催化剂的光催化活性进行了考察.结果表明掺杂后的TiO2光催化剂在可见光下对甲基橙能有效地降解,表现出了较好的光催化活性,当镍、锰离子掺杂量...     

钨掺杂氧化钛纳米管光催化降解结晶紫染料的性能

采用水热合成法制备了介孔TiO2纳米管,并以介孔TiO2纳米管为载体,钨酸铵为钨源,采用传统浸渍方法制备了WO3/TiO2纳米管复合材料.讨论了以WO3/TiO2纳米管为催化剂,影响结晶紫光催化降解率的主要因素,实验结果表明:光催化降解结晶紫溶液较好的符合一级反应动力学过程.以500℃焙烧的WO3/TiO2纳米管复合材料为光催化剂,当催化剂用量为500mg/L,结晶紫溶液的起始浓度20mg/L时,光照90min,结晶紫的降解率达到95％以上.另外,催化剂具有较高的稳定性,失活后的催化剂可以通过简单的培烧再生.     

RuO2/TiO2复合光催化剂的制备及性能研究

采用溶胶-凝胶-浸渍法制备了RuO2/TiO2复合光催化剂, 以紫外灯为光源, 直接耐晒黑G溶液的光催化降解为模型反应, 研究了RuO2/TiO2的光催化性能. 结果表明 掺杂量ω(RuO2)为0.16%、煅烧温度500 ℃、催化剂投加量为5.00 g·L-1时, RuO2/TiO2复合光催化剂催化活性最高. 直接耐晒黑G降解反应遵从Langmuir-Hinshelwood动力学模型, 测得反应速率常数为4.94×10-3 mmol(L·min)-1和吸附常数14.2 L·mmol-1.     

Ti(SO4)2水热法制纳米SO2-4/TiO2光催化剂的光谱研究

以Ti(SO4) 2 水溶液为前驱物 ,尿素为沉淀剂 ,采用水热沉淀 加热分解 浸渍烧结法制备纳米SO2 -4/TiO2 固体超强酸光催化剂 ,并用XRD ,BET ,FTIR ,DRS和FS等对中间态粒子和产物进行表征 ,以光催化降解罗丹明B为模型反应 ,筛选制备SO2 -4/TiO2 光催化剂的优化条件。结果表明 ,用Ti(SO4) 2 为前驱物 ,水热法能在较低的温度、弱碱性介质中 ,得到纳米锐钛矿型TiO2 晶体 ;在 30 0℃下控制焙烧 4h ,基本能使水热反应副产物 (NH4) 2 SO4等分解 ,又避免H2 SO4大量的流失 ;SO2 -4负载量和烧结时间是影响SO2 -4/TiO2 光催化活性的主要因素 ,当SO2 -4负载量 11%、烧结温度 4 5 0℃时 ,制备的SO2 -4/TiO2 光催化剂活性较高 ,达P 2 5光催化剂的水平     

Hydrophobic Functionalization of ZnO Nanosheets by In Situ Center‐Substituted Synthesis for Selective Photocatalysis under Visible Irradiation

The selective degradation of specific substances in mixed contaminants is quite challenging. And a general approach for sensitized oxide semiconductor relies on dip‐coating method with sensitizer. Here, hydrophilic 2D, nest‐like architecture ZnO (ZnO NA) was hydrophobicly functioned by monomolecular–layer tetraphenylporphyrin zinc (ZnTPP), where ZnTPP was synthesized by means of an in situ center‐substituted (ISCS) process., i.e., the hydrogen atoms in the core of metal‐free tetraphenylporphyrin (H₂TPP) are substituted by the unsaturated zinc ions in ZnO NAs. ZnTPP/ZnO NA was exhibited with significant hydrophobicity, benefitting to absorb hydrophobic phenol (PL). Further, it is realized to selectively photodegradate PL in the mixture by ZnTPP/ZnO NAs under visible irradiation. Note that the rate of degradation to hydrophobic PL by ZnTPP/ZnO NA is 9.17 times of that for ZnO NA within 150 min; on the contrary, the degradation rate of hydrophilic rhodamine B (RhB) by ZnTPP/ZnO is reduced by 40%. Radiative lifetime of photogenerated charges is obviously increased by ZnTPP/ZnO NA compared with that of ZnTPP, indicating the effective charge separation for ZnTPP/ZnO NAs. In addition, ZnTPP/ZnO NA produced more superoxide radicals (·O₂^?) in comparison to ZnO NA. With surface functionalization, the feasibility of selective photocatalysis under visible irradiation is demonstrated.     

10BaF₂:NaF,Na₃AlF₆/TiO₂ composite as a novel visible-light-driven photocatalyst based on upconversion emission

A rare-earth free upconversion luminescent material, 10BaF 2 :NaF, Na 3 AlF 6 , is synthesized by a hydrothermal method. The study of fluorescent spectrum indicates that it can convert visible light (550 nm–610 nm) into ultraviolet light (290 nm–350 nm), and two emission peaks at 304 nm and 324 nm are observed under the excitation of 583 nm at room temperature. Subsequently, 10BaF 2 :NaF, Na 3 AlF 6 /TiO 2 composite photocatalyst is prepared and its catalytic activity is evaluated by the photocatalytic reduction of CO 2 under visible light irradiation (λ > 515 nm). The results show that 10BaF 2 :NaF, Na 3 AlF 6 /TiO 2 is a more effective photocatalyst for CO 2 reduction than pure TiO 2 , their corresponding methanol yields are 179 and 0 μmol/g-cat under the same conditions. Additionally, the mechanism of photocatalytic reduction of CO 2 on 10BaF 2 :NaF, Na 3 AlF 6 /TiO 2 is proposed.     

Photofunctional Polyurethane Nanofabrics Doped by Zinc Tetraphenylporphyrin and Zinc Phthalocyanine Photosensitizers

Polymeric polyurethane nanofabrics doped by zinc tetraphenylporphyrin (ZnTPP) and/or zinc phthalocyanine (ZnPc) photosensitizers were prepared by the electrospinning method and characterized by microscopic methods, steady-state and time-resolved fluorescence, and absorption spectroscopy. Nanofabrics doped by both ZnTPP and ZnPc efficiently harvest visible light to generate triplet states and singlet oxygen O₂(¹Δ_g) with a lifetime of about 15 μs in air atmosphere. The energy transfer between the excited singlet states of ZnTPP and ground states of ZnPc is described in details. All nanofabrics have bactericidal surfaces and photooxidize inorganic and organic substrates. ZnTPP and ZnPc in the polyurethane nanofabrics are less photostable than incorporated free-base tetraphenylporphyrin (TPP).     

TiO_2/白云母纳米复合材料的色度学研究

利用化学液相沉积法制备了系列TiO2白云母纳米复合材料.在利用扫描电子显微镜、X射线衍射对其进行表面形貌、TiO2纳米镀层物相组成研究的基础上,仔细研究了TiO2白云母纳米复合材料在可见光下的反射光谱特征,并利用Munsell新坐标(HVC)色度学系统对其可见光下的干涉色颜色进行了定量表征. 关键词： TiO_2/白云母纳米复合材料 反射光谱 色度学 Munsell新坐标     

Synthesis and Spectral Characteristics for Zinc Tetraphenylporphyrin Modified Zinc Oxide NanowiresSynthesis and Spectral Characteristics for Zinc Tetraphenylporphyrin Modified Zinc Oxide Nanowires

A nest-like architectures(ZnO NAs)were prepared onto the conductive glass(ITO)by hydrothermal method.A metal-free porphyrin,tetraphenylporphyrin(H2TPP),was synthesized via Adler method.Zn ions with Zn-unsaturated coordination bonds on the surface of ZnO NAs were used as a template,and also H2TPP was used as"molecular fragments".Zinc tetraphenylporphyrin(ZnTPP)molecules were obtained on the surface of ZnO NAs by in-situ method.ZnO NAs direct provides of zinc source makes ZnTPP stably coated on the surface of ZnO NAs nanosheet,formed a tight composite materials(ZnTPP/ZnO NAs).Due toZnTPP with four phenyls in meso position,the surface of ZnTPP/ZnO NAs was with hydrophobic property.In the photocatalytic experiment,the degradation selectivity for phenol(hydrophobicity)in the mixture of phenol and rhodamine B(hydrophily)was increased under visible irradiation.     

TiO2/SiO2的表面化学修饰及其DRS和Raman光谱分析

以氯化醇钛盐表面反应法制备系列TiO2/SiO2,根据XRD,Raman和DRS表征分析,载体表面具有分子级分散的锐钛矿型TiO2微晶粒子和非晶TiOx物种.与本体TiO2相比,TiO2/SiO2的吸收带边显著蓝移,能隙增大为3.96 eV.当金属M(M:Pd,Cu和Ni)负载于TiO2/SiO2表面,可使其光吸收域扩展到可见光区,并引起吸收带边红移.相对Pd的负载,Cu,Ni的负载对TiO2/SiO2的LMCT带影响更大,其中Cu-TiO2/SiO2的能隙减小为3.68 eV.当金属氧化物MoO3负载于TiO2/SiO2上时,可以调变TiO2/SiO2的吸收带边并增强对可见光的吸收;随MoO3载量的增加,表面物种的相互作用增强,形成Mo-O-Ti复合结构,增强了LMCT带的吸收强度,并使能隙减小为3.81 eV.     

Sonochemical replication of chloroplast with titania for light harvesting

Hierarchy structure of granum in chloroplast was replicated onto titania using a simple and tactical sonochemical method and calcination. The structures of TiO(2) replicas were characterized by XRD, FE-SEM and TEM and the pore structures were characterized by N(2) adsorption/desorption. As a comparison, the preparation without sonication by using impregnation then calcination method was conducted, which shows the efficiency of the ultrasound on the exact replication of granum from micrometers down to nanometers. The optical properties of the TiO(2) replica, the chloroplast and the commercial pure TiO(2) powder together with the compared replica were measured by absorbance spectroscopy. It was found that the absorbance intensity of the TiO(2) replica made by ultrasonication is much better than the soaked one, and is twice of that of the pure TiO(2) powder in ultraviolet - visible light range. The excellent light harvesting performance of the TiO(2) is attributed to the combination of the functionality from the inorganic oxide and the fine hierarchical biological structures.     

Visible light induced sonophotocatalytic degradation of Reactive Red dye 198 using dye sensitized TiO2

In this paper we are reporting the accelerated sonophotocatalytic degradation of Reactive Red (RR) 198 dye under visible light using dye sensitized TiO(2) activated by ultrasound. The effect of sonolysis, photocatalysis and sonophotocatalysis under visible light has been examined to study the influence on the degradation rates by varying the initial substrate concentration, pH and catalyst loading to ascertain the synergistic effect on the degradation techniques. Ultrasonic activation at 47kHz contributes through cavitation leading to the splitting of H(2)O(2) produced by both photocatalysis and sonolysis. This results in the formation of oxidative species, such as singlet oxygen ((1)O(2)) and superoxide (O2-*) radicals in the presence of oxygen. Sonication increases the amount of reactive radical species, inducing faster oxidation of the substrate and degradation of intermediates and also the deaggregation of the photocatalyst which are responsible for the observed synergy. Further, the photocatalytic activity of RR 198 dye sensitized TiO(2) is demonstrated by the degradation of phenol under visible light and ultrasound. A comparative study using TiO(2), Hombikat UV 100 and ZnO was also carried out.     

反胶束软模板法合成PANI/TiO2纳米棒复合材料及其性能研究

以阳离子表面活性剂十六烷基三甲基溴化胺(CTAB)形成的反胶束为模板,制备了一系列不同纳米TiO2含量的PANI/TiI2纳米复合材料.利用FTIR,UV-Vis,TG,TEM和荧光光谱等方法对产物进行了结构表征和性能研究.探讨了反胶束体系中PANI/TiO2复合纳米棒形成的自组装机理.结果表明:复合材料主要为直径30～40 nm,长约400 nm的PANI/TiO2复合纳米棒,二氧化钛纳米粒子与聚苯胺大分子之间存在强的相互作用,并对复合材料的热稳定性起到提高作用,PANI/TiO2纳米复合材料在紫外和可见光区域均有吸收,并在416 nm处激发产生荧光,荧光强度随着掺杂TiO2含量的提高得到了较大的增强.通过PANI/TiO2纳米棒复合材料中的激子离化和电荷传输过程探讨了PANI/TiO2的荧光量子效率和荧光强度增加的机理.