Sonocatalytic degradation of methyl orange in the presence of (nanometer and ordinary) anatase TiO2 powders

The nanometer and ordinary anatase titanium dioxide(TiO2 ) powders were adopted as the sonocatalysts for the degradation of methyl orange used as a model compound for the first time. It was found that the sonocatalytic degradation effect of methyl orange in the presence of TiO2 powder were much better than that without TiO2, but the sonocatalytic activity of the nanometer anatase TiO2 particle was obviously higher than that of ordinary anatase TiO2 particle. Although there are many factors influencing sonocatalytic degradation of methyl orange, the experimental results showed that the best degradation ratio of methyl orange could be obtained when the experimental conditions were: initial concentration 15 mg/L, nanometer anatase TiO2 adding amount 750 mg/L, ultrasonic frequency 40 kHz, output power 50 W, pH = 3.0 and temperature 40℃ within 150 min. In addition, the catalytic activity of reused nanometer anatase TiO2 catalyst was also studied and found to decline gradually comparing with initial nanometer anatase TiO2 catalyst. All experiments indicated that the method of the sonocatalytic degradation of organic pollutants in the presence of TiO2 powder was an advisable choice for non-or lowtransparent organic wastewaters.     

超临界乙醇流体制取活性炭-TiO2光催化剂复合材料的研究

研究表明：在超临界乙醇流体介质下钛酸异丙酯能有效地分解成具光催化活性的锐钛矿型TiO2粒子，同时产生的TiO2粒子可与活性炭融合成一体，形成的活性炭－TiO2光催化剂复合材料具很好的光催化活性与吸附作用，而且具有的协同效应优于活性炭与TiO2样品的物理混合形式。     

3,5-二硝基水杨酸表面修饰纳米Ti2吸附对硝基苯酚

化学吸附法合成3,5-二硝基水杨酸表面修饰的TiO₂纳米粒子,TiO₂表面修饰后呈浅黄色,TiO₂表面羟基与3,5-二硝基水杨酸发生类似于醇和酸间的酯化反应.表层链接有苯环,极性减弱,非极性增强,在水、苯、乙醇中均分散性良好,与芳香族污染物的亲合力增强,有利于吸附去除芳香族污染物.表面修饰的TiO₂纳米粒子20mg,在最佳吸附pH值3、吸附时间10min,对100mL对硝基苯酚(3～10 mg/L)的吸附率可由改性前的43%增至99.9%.该法吸附效率高,可直接达到一级排放标准,提供了深度处理对硝基苯酚废水的新方法.     

低量Gd~3+掺杂TiO_2粉体的制备及催化活性

利用溶胶-凝胶法在700℃制备了纯的和不同Gd3+掺杂量的TiO2纳米粉体,并用XRD技术对样品进行了表征。研究了Gd3+掺杂量对样品相结构、晶粒尺寸和光催化降解亚甲基蓝的活性的影响,利用相结构与纳米TiO2光催化活性关系探讨了Gd3+掺杂对纳米TiO2的光催化活性。结果表明,与纯TiO2相比,适量掺杂Gd3+可以显著提高其光催化活性。当Gd3+掺杂量为0.2%(质量),TiO2复合纳米粉体的光催化活性最佳,降解率为86%,其金红石相含量为15.4%,平均晶粒粒径为15nm;Gd3+掺杂强烈地抑制TiO2由锐钛矿相向金红石相的转变、减小晶粒尺寸和晶格膨胀程度这三方面均有利于提高光催化活性。     

TiO2纳米粉体材料的制备及其脱除Hg蒸气污染物的研究

燃煤电站产生的汞污染物,是最难控制的巨毒、痕量污染物之一,已引起国内外广泛的研究兴趣.通过液相法制备了两种TiO2纳米粉体材料,对其结构和形貌采用TEM、BET和XRD进行了表征测试,在固定床反应器条件下初步测定了TiO2纳米粉体对单质汞Hg0污染物的脱除效果,研究表明,脱除效率随温度的升高而增加,最高可达60%.     

低温燃烧合成纳米Ni掺杂TiO2光催化剂的表征及活性研究

采用低温燃烧合成法制备了Ni掺杂TiO₂光催化剂,通过紫外-可见漫反射光谱(UV-Vis DRS)、X射线粉末衍射(XRD)、激光散射、热重-差示扫描量热分析(TG-DSC)等方法对催化剂的光吸收特性、晶相组成、粒度分布、升温过程中化学变化等进行了表征,以亚甲基蓝为模型污染物考察了催化剂在可见光下的光催化活性.结果表明,相对P25而言,Ni掺杂TiO₂的光吸收带边红移,当Ni/Ti原子比为0.4时,催化剂的带隙宽度为2.3eV,对应的吸收带边为564nm;催化剂晶型以锐钛矿TiO₂为主,随Ni掺杂量增大,NiTiO₃比例升高;催化剂粒径主要分布在50～150nm之间,占总量的96.9%;升温过程中催化剂在445.2℃发生晶型转化,出现锐钛矿和NiTiO₃晶体.催化剂显示出较高的催化活性,在可见光作用150min后最高可使93.9%的亚甲基蓝分解,活性高于P25.     

Visible light induced photodegradation of organic pollutants on nitrogen and fluorine co-doped TiO2 photocatalyst

The nitrogen and fluorine co-doped TiO2 polycrystalline powder was synthesized by calcinations of the hydrolysis product of tetrabutyl titanate with ammonium fluoride. Nitrogen and fluorine co-doping causes the absorption edge of TiO2 to shift to a lower energy region.The photocatalytic activity of co-doped TiO2 with anatase phases was found to be 2.4 times higher than that of the commercial TiO2 photocatalyst Degussa P‘25 for phenol decomposition under visible light irradiation. The co-doped TiO2 powders only contain anatase phases even at 1000%. Apparently, ammonium fluoride added retarded phase transformation of the TiO2 powders from anatase to futile.The substitutional fluorine and interstitial nitrogen atoms in co-doped TiO2 polycrystalline powder were responsible for the vis light response and caused the absorption edge of TiO2 to shift to a lower energy region.     

Influences of working pressure on properties for TiO2 films deposited by DC pulse magnetron sputtering

TiO2 films were deposited at room temperature by DC pulse magnetron sputtering system.The crystalline structures,morphological features and photocatalytic activity of TiO2 films were systematically investigated by X-ray diffraction (XRD),atomic force microscopy and ultraviolet spectrophotometer,respectively.The results indicated that the working pressure was the key deposition parameters influencing the TiO2 film phase composition at room temperature,which directly affected its photocatalytic activity.With increasing the working pressure,the target self-bias decreases monotonously.Therefore,low temperature TiO2 phase (anatase) could be deposited with high working pressure.The anatase TiO2 films deposited with 1.4 Pa working pressure displayed the highest photocatalytic activity by decomposition of Methyl Orange solution,which the degradation rate reached the maximum (35%) after irradiation by ultraviolet light for 1 h.     

漂浮型N-TiO_2/EP的制备表征及其光催化性能研究

以轻质、多孔的非金属矿物膨胀珍珠岩(Expanded perlite,EP)为载体,采用载体表面水合沉淀法制备出漂浮型N-TiO2/EP光催化剂,并利用X射线衍射、扫描电镜等分析技术,对N-TiO2/EP进行了表征。以辛烷模拟水面溢油,探讨了N掺杂对TiO2催化性能的影响。结果发现N掺杂可以抑制TiO2由锐钛矿向金红石的转变,焙烧温度为400℃时,N-TiO2/EP的催化活性最高。0.15g的N-TiO2/EP催化剂用于光降解0.5mL辛烷时,紫外光照射4h后,辛烷去除率达到96.02%。改用氙灯模拟太阳光照射,N-TiO2/EP的辛烷去除率达到82.14%,TiO2/EP的辛烷去除率为53.57%。     

乙二胺溶胶凝胶法氮掺杂TiO_2的光催化研究

以钛酸四丁酯(TBT),乙二胺(EDA)为前驱体,乙醇为溶剂,冰醋酸为抑制剂,采用溶胶-凝胶法制备了N掺杂纳米TiO2光催化剂。通过紫外-可见吸收光谱(UV-Vis)、荧光发射光谱(FES)、X射线衍射光谱(XRD)、X射线光电子能谱(XPS)、和BET比表面分析对其光谱特征、晶相结构、表面组成、比表面积进行了表征,以苯酚为模拟污染物考察了其光催化活性。结果表明:该方法制备的N掺杂纳米TiO2的光谱吸收带发生了明显红移,当EDA/TBT(摩尔比)=1/10及焙烧温度为550℃时,所制备样品对可见光的吸收最强,可见光照射150min苯酚的降解率为34.6%,紫外光照射100min苯酚的降解率达到97.8%。     

不同煅烧温度制备TiO_2及光解2-氯苯甲酸

为了考察煅烧温度对TiO2结构和光催化活性的影响,以酞酸丁酯作为前驱体,利用溶胶-凝胶法在不同煅烧温度下制备TiO2,并用亚甲基蓝测试其光催化活性。TG热重分析表明,450~700℃时TiO2有晶型变化,XRD表征说明,TiO2晶型受煅烧温度影响显著,其中450~600℃煅烧制备的TiO2为锐钛矿型,650℃煅烧时TiO2出现金红石晶型;亚甲基蓝光解实验结果表明,煅烧温度显著影响TiO2的光催化活性,其中,450~600℃煅烧TiO2对亚甲基蓝光解效果较好,光降解2.5h后降解率高达95%~97%;550℃煅烧制备的锐钛矿型TiO2对2-氯苯甲酸有一定光解催化效果,紫外光解4h后降解率高达80%左右,光解过程符合零级动力学模式。     

混晶纳米TiO_2的制备及其光催化降解有毒有机污染物

以无定形TiO2沉淀为前驱体,在水热条件下得到了含板钛矿(121)相混晶纳米TiO2,考察了水热反应的温度和时间等因素对含板钛矿型TiO2光催化活性的影响.采用XRD、TEM对制备的TiO2进行初步表征,并结合光催化(λ≤387 nm)降解有机染料的光活性探针反应.结果表明,水热温度为150℃,时间为24 h时,可制得具有较高光催化活性的纳米TiO2,其纳米尺寸为14.20 nm,板钛矿相含量63.6%,锐钛矿含量为36.4%.光催化实验中跟踪研究了其对染料酸性桃红(sulforhodmineB,SRB)的褪色及2,4-DCP的降解情况,并对降解中间产物H2 O2、.OH进行跟踪测定,实验结果表明板钛矿相混晶TiO2的光催化主要涉及.OH氧化历程,光照射9 h对SRB和2,4-DCP的矿化氧化分别达到89%和78%,循环5次光催化降解SRB实验,催化剂表现出较好的稳定性,催化性能无明显变化.     

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     

纳米掺氮TiO_2可见光降解环境内分泌干扰物BPA研究

用水湿法得到掺氮TiO2前体,热处理后得到掺氮TiO2粉体,用XRD和UV-Vis吸收光谱等手段对制备的掺氮TiO2进行了表征,并研究了N-TiO2可见光光催化降解环境内分泌干扰物双酚A。结果表明掺氮TiO2在400℃下煅烧1h,所得粉体是锐钛矿相结构,粒径约12nm,与纯TiO2相比,吸收边明显红移。催化剂掺氮TiO2具有可见光催化活性,且明显高于纯TiO2。在双酚A初始浓度为40mg/L,催化剂掺氮TiO2的煅烧温度为400℃,投加量为0.6g/L,pH=5的条件下的降解效果最好达48.91%。     

金属泡沫镍负载纳米TiO2光催化降解甲醛和VOCs

采用溶胶-凝胶法制备了3种掺杂金属离子的纳米TiO₂光催化剂,并将其负载于泡沫镍板上,以室内空气典型污染物甲醛和VOCs为模型反应物,研究了对甲醛和VOCs气体的光催化作用并讨论了La³⁺的最佳掺杂比例以及环境因素对光催化效率的影响.结果表明:该TiO₂催化剂具有良好的锐钛矿型结构;负载掺La 1.5%TiO₂的泡沫镍板90min对甲醛和VOCs的降解率分别为94%和87%,远高于未掺:83%和72%,掺Fe     

TiO_2/Ti薄膜电极制备和光电催化降解罗丹明B的研究

以TA1钛合金为原料采用阳极氧化法制备新型薄膜电极 -TiO2 Ti电极 ,运用X射线衍射法、扫描电镜对电极表面膜的粒径、物相进行了表征。结果表明 ,控制反应条件 ,薄膜中二氧化钛晶型以锐钛矿型为主 ,粒径 45～ 5 0nm ,将其应用于光催化氧化水中的罗丹明B ,该电极对其降解有很好的光催化活性 ,同时 ,外加一定的偏压可以提高光催化氧化的效率     

Photoelectrocatalytic degradation of Rose Bengal

An innovative photoelectrode, TiO2/T1 mesh electrode, was prepared by galvanostaticanodisation. The morphology and the crystalline texture of the TiO2 film on mesh electrode were examined by scanning electronic microscopy and Raman spectroscopy respectively. The examination results indicated that the structure and properties of the film depended on anodisation rate, and the anatase was the dominant component under the controlled experimental conditions. Degradation of Rose Bengal (RB) in photocatalytic (PC) and photoelectrocatalytic (PEC) reaction was investigated, the results demonstrated that electric biasing could improve the efficiency of photecatalytic reaction. The measurement results of TOC in photoelectrocatalytic degradation showed that the mineralisation of RB was complete relatively. The comparison between the degradation efficiency of RB in PEC process and that in aqueous TiO2 dispersion was conducted. The results showed that the apparent first-order rate constant of RB degradation in PEC process was larger than that in aqueous dispersion with 0.1%--0.3% TiO2 powder, but was smaller than that in aaueaus disverslon with 1.0% TiO2.     

铕掺杂纳米二氧化钛光催化实验研究

以钛酸丁酯为原料,乙醇为溶剂,硝酸为抑制剂。采用溶胶凝胶法制备纳米粒子TiO2,用30w的紫外光灯模拟光源,溴甲酚紫模拟水中难降解的有机污染物,采用稀土铕掺杂的方法来提高TiO2的活性。XRD研究结果表明,稀土铕掺杂TiO2没有改变纳米TiO2的晶相结构;光催化结果表明,稀土铕掺杂的确能较明显的提高TiO2的光催化降解能力。90min内达到降解率由80%提高到98%以上。     

纳米TiO2薄膜在不同基质表面的负载及光催化性能

以釉面陶瓷和普通钠钙玻璃为载体,用溶胶凝胶法在其表面进行了纳米TiO2薄膜的负载.采用X射线衍射法(XRD)、扫描电子显微镜(SEM)和X射线光电子能谱仪(XPS)对薄膜进行了表征与分析.结果表明,TiO2为完全的锐钛矿型,平均粒径约为15nm;TiO2薄膜在2种载体上分布均匀,膜厚约为300nm;TiO2薄膜在釉面陶瓷表面呈连续分布,而在玻璃表面上出现了破裂现象;2种载体中的一些基质离子在TiO2薄膜均有渗透.光降解实验表明,2种载体上的TiO2薄膜对亚甲基蓝的降解均符合一级反应动力学.TiO2/釉面陶瓷催化活性大于TiO2/玻璃,该薄膜对实际生产多菌灵废水具有催化降解作用.2种载体上的TiO2薄膜重复使用20次,对亚甲基蓝的去除率降低约2%.     

混晶纳米TiO_2薄膜光催化降解亚甲基蓝

以钛酸四丁酯为原料采用浸渍提拉法在普通瓷片表面制备TiO2混晶薄膜,用XRD对薄膜进行表征,选用亚甲基蓝催化降解考察TiO2混晶薄膜的催化能力,探讨了紫外光光照强度、亚甲基蓝初始浓度和pH对光催化降解的影响。结果表明:600℃煅烧4h可制备金红石为13.2%的混晶薄膜,平均粒径为22nm;初始浓度在0.313～0.937mg/L,催化反应符合一级动力学方程,半衰期随初始浓度的增加而减小;在光照强度为40W和pH为13时降解率为45.6%,并可多次重复使用。