玻璃纤维附载TiO2光催化降解有机磷农药

研究以四异丙醇钛为原料,配制成胶体用玻璃纤维附载ＴｉＯ２的过程;同时利用附载的ＴｉＯ２光催化降解有机磷农药。结果表明,低浓度的４种有机磷农药,３７５Ｗ中 汞灯短时间照射有机磷将完全被光催化氧化至ＰＯ＾３－４;玻璃纤维上附载的ＴｉＯ２不易脱落。     

光催化降解有机磷农药废水的可行性

在ＴｉＯ２粉末的存在下，研究光催化降解有机磷农药废水的可行性。结果表明，ＣＯＤｃｒ６５０ｍｇ／Ｌ，有机磷１９．８ｍｇ／Ｌ的有机磷农药废水在３７５Ｗ中压汞灯照射４ｈ，ＣＯＤ去除率为９０％，有机磷将完全转化为无机磷。同时还研究了光催化剂ＴｉＯ２的用量，反应液初始ｐＨ值，空气流量，外加Ｆｅ３＋浓度等多种因素对光降解的影响；并利用太阳聚光做了室外实验     

稀土元素掺杂二氧化钛催化剂光降解久效磷的研究

采用浸渍法制备稀土掺杂二氧化钛光催化剂，通过光催化降解农药久效磷的研究，发现掺杂稀土元素对ＴｉＯ２的光催化性能有明显的影响，特别是Ｃｅ＾４＋、Ｌａ＾３＋等能明显提高ＴｉＯ２的光催活性，并讨论了催化剂的制备，光降解条件诸因素对光降解久效磷的影响。     

掺入金属离子的TiO2纳米粒子光催化降解吖啶橙

利用酸催化溶胶－凝胶法（ｓｏｌ－ｇｅｌ）制备了 Ｆｅ３＋和 Ｃｒ３＋不同掺入量的 ＴｉＯ２半导体纳米粒子研究了这些纳米粒子对吖啶橙光催化氧化降解的影响．结果表明，微量 Ｆｅ３＋和 Ｃｒ３＋的掺入可明显提高 ＴｉＯ２的光催化活性．进一步研究表明，在 Ｆｅ３＋－ＴｉＯ２体系中，最佳掺入量为 ０．１％，而且中性介质和自然光有利于光催化氧化反应的进行，反应３ｈ后降解率可达９７．７５％．在Ｃｒ３＋－ＴｉＯ２体系中，弱碱性介质和自然光有利于光催化氧化反应，最佳掺入量为０．０５％，降解率可达８７．５４％．     

光催化降解有机磷农药的研究

研究以ＴｉＯ２粉末作为光催化剂,光降解３种不同结构的有机磷农药的可行性。结果表明,有机磷农药结构不同其光降解率不同;浓度１．０×１０－４ｍｏｌ／Ｌ的４种有机磷农药,３７５Ｗ中压汞灯照射４０ｍｉｎ有机磷将完全转变为无机磷,并检测出人效磷农药催化降解的部分中间产物。研究光催化剂ＴｉＯ２的用量、空气流量、外加Ｆｅ３＋浓度对光催化降解的影响,并初步探讨了机理。     

水溶液中十二烷基苯磺酸钠的半导体光催化降解的研究

以ＴｉＯ２为催化剂,以３００Ｗ高压汞灯为光源,对水溶液中的十二烷基苯磺酸钠进行了半导体光催化降解,研究不同ｐＨ条件下金红石型和锐钛型ＴｉＯ２的光催化活性及Ｈ２Ｏ２,Ｃｕ＾２＋的加入对降解的影响,结果表明,锐钛型ＴｉＯ２具有较高的催化活性;Ｈ２Ｏ２在碱性条件下能抑制ＤＢＳ的光催化降解,在无ＴｉＯ２时,Ｈ２Ｏ２对ＤＢＳ有光催化氧化作用,在酸性条件下,Ｃｕ＾２＋对ＤＢＳ的ＴｉＯ２光催化降解有较强的助催化     

固定化微生物对水胺胺磷降解机理的研究

采用气相色谱－质谱联机和有关分析方法，给出了精品水胺硫磷的质谱图；证实固定化微生物可使有机磷农药水胺硫磷的环链断裂，其最终产物为ＣＯ２、Ｈ２Ｏ、ＮＨ３、Ｈ２Ｓ、Ｈ３ＰＯ４等简单无机化合物；初步推断水杨酸异丙酯等有机化合物是降解过程的中间产物。     

固定化微生物对水胺硫磷降解机理的研究

采用气相色谱一质谱联机和有关分析方法,给出了精品水胺硫磷的质谱图;证实固定化微生物可使有机磷农药水胺硫磷的环链断裂,其最终产物为ＣＯ２、Ｈ２Ｏ、ＮＨ３、Ｈ２Ｓ、Ｈ３ＰＯ４等简单无机比合物;初步推断水杨酸异丙酯等有机化合物是降解过程的中间产物。     

光催经氧化法处理染料中间体H酸水溶液

为了去除水中难氧化的有害染料中间体Ｈ酸，研究以ＴｉＯ２，ＺｎＯ，ＣｄＳ和Ｆｅ２Ｏ３为催化剂，采用低压汞灯为光源，对Ｈ酸水溶液进行光催化氧化实验。结果表明：ＴｉＯ２和ＣｄＳ的催化效果最好。采用ＴｉＯ２作催化剂，光催化氧化５ｈ后，Ｈ酸分解率可达９０％，反应速率遵大Ｌａｎｇｍｕｉｒ－Ｈｉｎｓｈｅｌｗｏｄｄ方程，Ｋ＝１２．３Ｌｍｍｏｌ，ｋ＝２５．２×１－０＾－６ｍｏｌ／ｈ。     

附着态半导体光催化剂光解可溶性染料的研究

以３００Ｗ中压汞灯和日光为光源，研究了将ＴｉＯ２等半导体粉末附着在海砂和玻璃表面对直接耐晒大红４ＢＳ（下简称４ＢＳ）、活性黑ＫＮ－Ｂ（下简称ＫＮ－Ｂ）和亚甲基蓝（下简称ＭＢ）水溶液的催化光解。结果表明：几种染料均显光解；光解为一级动力学反应；附着复合的ＴｉＯ２－Ｆｅ２Ｏ３、ＴｉＯ２－ＷＯ３比附着单一的ＴｉＯ２光催化效果好；附着态ＴｉＯ２重复使用１５次（每次８ｈ）后催化能力降低１７．９％。以基态电     

TiO2-石墨烯（Gn）复合材料光催化降解O3研究

通过改性Hummer法及溶胶凝胶法,制备出TiO2-石墨烯光催化复合材料.经吸附-光催化活性实验选出光催化活性最高的含C量为1.5%(质量分数)的TiO2-石墨烯复合材料,并在自行设计的模拟大型客机环境的气相光催化反应器中,进行O3光催化降解实验研究.结果表明,TiO2-石墨烯复合光催化材料在较短时间内对O3有较高的降解效率,且其光催化活性显著优于纯TiO2材料.初始O3浓度为(0.150～0.200)×10-6时,复合光催化剂受紫外光激发60 min的光催化降解率为66.12%,初始O3浓度为(0.950～1.000)×10-6时,其光催化降解率约为77%,较低浓度时((0.100～0.150)×10-6),O3去除率也能达到45.45%.此外,通过探讨光催化材料的重复使用性能,表明复合光催化剂重复使用4次以内,其对O3的光催化降解率保持基本稳定.     

氧化剂增强TiO2纤维光催化降解DMF研究

研究TiO₂纤维光催化降解DMF水溶液的结果表明:氧化剂增强了TiO₂纤维对DMF的降解能力,在其它反应条件相同情况下,O₃/TiO₂(F)对DMF降解率是air/TiO₂(F)和H₂O₂/TiO₂(F)的1.5倍左右,且降解速率提高2倍左右,COD分析表明DMF几乎完全矿化.同时实验过程中确定了DMF光催化降解中间产物仲胺的存在.以二甲胺为仲胺代表物进行光催化降解研究表明,中间产物仲胺的迅速降解是O₃增强TiO₂纤维降解效应的主要因素.     

TiO2投加量及其表面载银量对光催化降解Aro-clor1260的影响

在紫外灯照射下,催化剂TiO₂的投入量及其表面载银量对光催化降解Aroclor1260有显著的影响.但TiO₂的投入量并不与Aroclor1260的降解速率成正比关系,而是有一个最佳投入量,在本文的实验条件下,这个最佳值为60mg(3g/L).TiO2的表面载银量越多,Aroclor1260的降解速率也越大,而且浓度相对较高的PCB单体化合物的降解速率大于浓度相对较低的PCB单体化合物的降解速率.对于多数PCB单体化合物而言,TiO₂的催化活性随其表面载银量的增加而增强.     

Effects of environmental factors on sulfamethoxazole photodegradation under simulated sunlight irradiation: Kinetics and mechanism

To advance the knowledge of the environmental fate of sulfamethoxazole (SMX), we systematically investigated the effects of natural water constituents and synthetic substances (i.e., TiO₂ nanoparticles (nTiO₂) and Ti-doped β-Bi₂O₃ (NTB)) on the photodegradation kinetics of SMX under xenon lamp irradiation. The photolysis of SMX in aqueous solution followed first-order kinetics. Our results showed that higher concentrations of SMX, fulvic acid, suspended sediments, NTB and higher pH value decreased the photodegradation rates of SMX, whereas H₂O₂ improved the SMX photodegradation. TiO₂ nanoparticles had a dual effect on photodegradation due to their photocatalytic activity and photoabsorption of photons. No intermediates more toxic toward Vibrio fischeri than SMX were produced after direct photolysis and photocatalytic degradation for 3 hr. The photolysis of SMX involved three pathways: hydroxylation, cleavage of the sulfonamide bond, and fragmentation of the isoxazole ring. This study lays the groundwork for a better understanding of the environmental fate of SMX.     

Photocatalytic degradation of organochlorine compounds using TiO2 supported on fiberglass cloth

The feasibility of photocatalytic degradation of organochlorine compounds using TiO₂ supported on fiberglass cloth as a photocatalyst was studied. The results showed that 2.0×10^-4 mol/dm³ of dichloroethylene, trichloroethylene and tetrachloroethylene can be completely photocatalytically degraded within a short time under illumination with a 375W medium pressure mercury lamp. The effects of parameters such as illumination time, initial concentration of organochlorine compounds, amount of air flow and concentration of H₂O₂ on the photocatalytic degradation were investigated. The TiO₂ supported on the fiberglass was not easily detached and after 500h illumination there was no significant loss of photocatalytic activity of TiO₂. The passible mechanisms of photocatalytic degradation were discussed.     

上转换发光剂掺杂纳米TiO2的制备及可见光降解乙基紫的研究

合成了一种新型含有稀土金属Er的上转换发光剂40CdF₂·60BaF₂·1.6Er₂O₃,此上转换发光剂在488 nm可见光的激发下,产生了5个波长均小于387 nm的上转换紫外光发射峰.采用超声波分散的方法制备出了上转换发光剂掺杂的纳米TiO₂可见光光催化剂.利用X-射线衍射(XRD)及透射电镜(TEM)对催化剂进行了表征.以乙基紫染料为研究对象,研究了在(三基色灯下发出的)可见光的照射下该可见光光催化剂的催化降解性能,并与未掺杂的纳米TiO₂粉末的催化性能进行了对比.结果表明,作为掺杂成分的上转换发光剂可有效地将可见光转化为紫外光并被纳米TiO₂粉末吸收利用,在可见光照射12.0 h后乙基紫降解率达到了99.68%,大大高于未掺杂纳米TiO2时的降解率.     

WC/TiO2纳米复合界面光催化剂制备及其光催化降解酚类污染物研究

设计并制备了新型WC/TiO2纳米复合界面光催化剂应用于酚类污染物的光催化降解反应中.采用X射线衍射(XRD)和扫描电子显微镜(SEM)技术分析了WC/TiO2纳米复合界面光催化剂的晶型和表面形貌.结果显示锐钛矿型TiO2纳米颗粒均匀地分散在WC纳米球表面并很好地构筑了WC/TiO2界面.研究了不同WC负载比例的WC/TiO2光催化剂在模拟太阳光照射下降解苯酚的光催化性能.结果表明:WC/TiO2复合界面的形成可以有效地提高TiO2光催化降解性能;其中,3%WC/TiO2(质量分数)光催化降解苯酚的活性最高.利用紫外-可见光谱(UV-Vis)和高效液相色谱-质谱联用技术(HPLC-MS)分析了WC/TiO2纳米复合界面光催化剂降解苯酚的中间产物,提出了苯酚在WC/TiO2界面上可能的降解机理.     

Solar photocatalytic decomposition of two azo dyes on multi-walled carbon nanotubes (MWCNTs)/TiO2 composites

Multi-walled carbon nanotubes (MWCNTs)/TiO₂ composite photocatalysts with high photoactivity were prepared by sol-gel process and further characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), and UV-vis absorption spectra. Compared to pure TiO₂, the combination of MWCNTs with titania could cause a significant absorption shift toward the visible region. The photocatalytic performances of the MWCNTs/TiO₂ composite catalysts were evaluated for the decomposition of Reactive light yellow K-6G (K-6G) and Mordant black 7 (MB 7) azo dyes solution under solar light irradiation. The results showed that the addition of MWCNTs enhanced the adsorption and photocatalytic activity of TiO₂ for the degradation of azo dyes K-6G and MB 7. The effect of MWCNTs content, catalyst dosage, pH, and initial dye concentration were examined as operational parameters. The kinetics of photocatalytic degradation of two dyes was found to follow a pseudo-first-order rate law. The photocatalyst was used for seven cycles with photocatalytic degradation efficiency still higher than 98%. A plausible mechanism is also proposed and discussed on the basis of experimental results.     

Enhanced photocatalytic activity of fish scale loaded TiO2 composites under solar light irradiation

Fish scale (FS) loaded TiO₂ composites were investigated as photocatalysts in degradation of Methyl Orange under solar light irradiation. Composites were prepared through sol-gel method by varying mass ratio of TiO₂/FS at 90:10, 70:30 and 50:50, respectively. The catalysts prepared in this study were characterized by using XRD, SEM, FT-IR and nitrogen sorption. The effects of solar irradiation, mass ratio of TiO₂/FS composites, irradiation time and catalyst loadings were studied. Synergistic effect was found in TiO₂/FS of 90:10 composite which performed higher photocatalytic degradation than synthesized TiO₂ under solar light irradiation. However, further increasing fish scale content in the composites reduced the photocatalytic activity drastically. Under solar light irradiation, all the catalysts in this study exhibited photocatalytic activity, except TiO₂/FS of 50:50 composite that only acted as a weak biosorbent without performing any photocatalytic property. Photocatalytic degradation increased with increasing catalyst loading and irradiation time but decreased with increased of initial dye concentration.     

Photocatalytic degradation of phenanthrene on soil surfaces in the presence of nanometer anatase TiO2 under UV-light

The effect of nanometer anatase TiO₂ was investigated on the photocatalytic degradation of phenanthrene on soil surfaces under a variety of conditions. After being spiked with phenanthrene, soil samples loaded with different amounts of TiO₂ (0 wt.%, 1 wt.%, 2 wt.%, 3 wt.%, and 4 wt.%) were exposed to UV-light irradiation for 25 hr. The results indicated that the photocatalytic degradation of phenanthrene followed the pseudo first-order kinetics. TiO₂ significantly accelerated the degradation of phenanthrene with the half-life reduced from 45.90 to 31.36 hr for TiO₂ loading of 0 wt.% and 4 wt.%, respectively. In addition, the effects of H₂O₂, light intensity and humic acid on the degradation of phenanthrene were investigated. The degradation of phenanthrene increased with the concentration of H₂O₂, light intensity and the concentration of humic acids. It has been demonstrated that the photocatalytic method in the presence of nanometer anatase TiO₂ was a very promising technology for the treatments of soil polluted with organic substances in the future.