不同钛源掺碳二氧化钛可见光催化活性的研究

为拓展二氧化钛对可见光的响应,采用溶胶-凝胶法、水解法制备了碳掺杂二氧化钛粉末。用X射线衍射、比表面分析和紫外-可见光漫反射吸收光谱等方法对制备的样品进行了表征,对可见光照射下的光催化活性进行了测试,并考察了煅烧温度对光催化活性的影响。结果表明：碳掺杂致使二氧化钛在可见光区的光吸收增强,在降解甲基橙的实验中表现出良好的可见光催化活性;随煅烧温度的增加,晶粒增大,可见光催化活性减弱。     

碳纳米材料掺杂二氧化钛纳米棒催化剂制备方

正本发明公开了一种碳纳米材料掺杂二氧化钛纳米棒催化剂制备方法。先分别制备出二氧化钛纳米棒和碳纳米材料,再采用冷凝回流的方法完成碳纳米材料掺杂到二氧化钛纳米棒的制备。在制备过程中,通过控制二氧化钛纳米棒中碳的不同体积比,能够使掺杂后光催化材料对可见光具有响     

铁掺杂二氧化钛的结构及其可见或紫外光下对有机物催化降解的行为探析

采用水热法制备出铁掺杂二氧化钛晶体粉末,以红外光谱仪和X射线衍射仪对其结构进行分析,研究光催化剂在可见光或者紫外光的照射下对有机物的催化降解行为,经过红外光谱仪的分析,以水热法制出备的二氧化钛结构中含有大量的羟基成分,具有良好的光催化活性,而经过X射结衍射仪的测试分析,制备出的二氧化钛晶体属于锐钛矿型,另外,在相同条件下,紫外光照射下的甲基紫降解效率要好于可见光,在优化条件下,掺杂2%的铁的二氧化钛晶粉末对甲基紫的最大降解率分别为59.44%和96.12%,不掺杂铁的二氧化钛晶体粉末的光催化降解率分别为26.53%和41.89%,而掺杂8%的铁的二氧化钛晶体粉末的光催化降解率分别为37.57%和48.61%。     

一锅法合成C@TiO2复合材料及其可见光催化性能研究

通过简单、绿色的一锅法,在水热条件下合成了高活性纳米C@TiO2光催化剂。对样品进行了透射电镜(TEM)分析、X射线能量色散谱分析(EDS)、X射线衍射(XRD)分析、X射线光电子能谱分析(XPS)、紫外可见吸收光谱(UV-Vis)分析、BET分析及在可见光照射下光催化性能测试。结果表明,采用一锅法可以将碳均匀负载在二氧化钛纳米粒子表面;葡萄糖的存在可以抑制金红石矿和板钛矿晶型二氧化钛的产生,有利于形成锐钛矿晶型二氧化钛;XPS结果表明碳未掺杂到二氧化钛晶格中。C@TiO2复合材料可以吸收全光谱范围的可见光,并且在可见光照射下具有良好的光催化活性。分析表明碳与二氧化钛表面的化学作用有效促进了材料的可见光催化性能。此材料合成方法简单、绿色,可见光催化效果好,有较好的工业应用前景。     

固相合成N/Fe共掺杂TiO2及可见光降解葛根素

采用简单固相反应法分别合成了铁掺杂二氧化钛(Fe-TiO2)及氮和铁共掺杂二氧化钛(N/Fe-TiO2)光催化粉体材料,并对材料进行了X射线衍射(XRD)、紫外-可见光光谱(UV-Vis)、X射线光电子能谱(XPS)等物相结构及元素组成表征,同时研究了材料对葛根素的可见光降解性能.结果表明,N和Fe进入了TiO2晶格,...     

一步法原位制备碳氮共掺杂TiO_2纳米材料及其光催化制氢性能

采用碳化钛(TiC)粉末在氨气气氛中煅烧的方法一步原位制备了碳氮共掺杂的TiO_2纳米材料。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)和紫外-可见漫反射谱(UV-VisDRS)等手段对其进行了表征。UVVisDRS分析结果表明,碳氮共掺杂的TiO_2的吸收带边较TiO_2有明显地红移且吸收强度增大。研究了热处理温度对样品的光催化产氢性能的影响,结果表明,550℃所制备的样品的光催化活性最好。相对于纯TiO_2和碳掺杂TiO_2,C和N的引入提高了TiO_2在紫外-可见光区的光催化制氢性能。     

镍、碳共掺杂纳米二氧化钛薄膜的制备与光催化性能研究

为了增强纳米二氧化钛薄膜在紫外光下光催化降解罗丹明B溶液的能力,分别采用磁控直流溅射与射频溅射的方法,使用二氧化钛靶材、镍靶材、碳靶材,分别制备了碳非金属掺杂、镍金属掺杂以及镍、碳共掺杂的纳米二氧化钛薄膜,并利用扫描电子显微镜（SEM）、X射线衍射仪（XRD）和紫外可见分光光度计（UV-Vis）进行表征。SEM结果表明,与纯二氧化钛薄膜相比镍、碳共掺杂纳米二氧化钛薄膜晶粒细化,比表面积增大,薄膜表面聚集体为不规则的多边形颗粒状,有利于增大与污染物的接触面积;XRD结果表明该薄膜的晶粒减小,加快了光生电子空穴对的分离;薄膜的吸收极限红移,禁带宽度减小。在紫外光照射下,镍、碳共掺杂纳米二氧化钛薄膜的光催化性能最优,1 h降解了29.54%的罗丹明B溶液。     

ZIF-8制备原位碳掺杂氧化锌及其光催化性能研究

以ZIF-8为前驱体,采用热解法制备碳掺杂氧化锌。分别研究ZIF-8在350、400、450 ℃下煅烧以及陈化10 min、3 h、24 h对制备原位碳掺杂氧化锌的影响。通过热重（TG）、X射线衍射（XRD）和扫描电镜（SEM）研究样品的形貌和结构;紫外可见漫反射光谱（UV-vis）和光致发光光谱（PL）证明原位碳掺杂氧化锌具有可见光吸收能力和更低的光生载流子复合率;DFT模拟计算表明氧化锌晶格中掺入碳元素能有效减小带隙值。原位碳掺杂氧化锌较纯氧化锌在可见光和紫外光照射下的光催化性能分别提高1.5倍和3.0倍。空穴和羟基自由基是原位碳掺杂氧化锌光催化降解体系的主要活性基团,并由此提出了碳掺杂氧化锌的光催化机理。     

加氢改性二氧化钛的可见光光催化性能研究

针对二氧化钛的禁带宽度大、太阳能利用率低的问题,对合成的纳米二氧化钛部分加氢还原改性,制备了可见光响应二氧化钛光催化材料。水热法合成了锐钛矿相的二氧化钛纳米粒子,用高压低温加氢还原和常压高温加氢还原两种方法进行改性,用X射线粉末衍射仪、扫描电子显微镜表征其结构和形貌,用固体紫外漫反射光谱研究其光响应范围,以罗丹明B的可见光降解反应为探针反应,初步研究其光催化性能,结果表明常压高温加氢处理后的锐钛矿二氧化钛纳米粒子具有更好的可见光光催化性能。     

掺铁二氧化钛纳米晶的制备及其光催化性能

通过溶胶-凝胶法室温制备了掺杂铁二氧化钛纳米晶光催化剂。采用透射电子显微镜、X射线衍射仪、能谱元素分析仪、紫外-可见分光光度计等对所得产物进行表征。以甲基橙为目标降解物,对未掺杂的二氧化钛纳米晶及掺杂铁的二氧化钛纳米晶进行了光催化降解性能研究,并对其降解机理进行了分析。结果表明:适量的铁掺杂有利于提高二氧化钛纳米晶的光催化性能和对甲基橙的降解率。铁的最佳掺杂量为25%[Fe占(Ti+Fe)的摩尔分数]。掺杂铁的二氧化钛纳米晶光催化性能优于纯二氧化钛纳米晶,在光照150min后,甲基橙的降解率达75%以上。     

Synthesis and characterization of carbon-doped titania as a visible-light-sensitive photocatalyst

The synthesis and use of carbon-doped TiO₂ particles in photocatalysis under visible light are demonstrated. The carbon-doped titania with its mesoporous structure was prepared by chemical modification and characterized by several techniques including X-ray diffraction, transmission electron spectroscopy (TEM), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance spectra (EPR), and diffuse reflectance UV-Vis. absorption spectra, with emphasis on the effect of carbon as a doping compound to the titania. Based on EPR data, the photocatalytic activity by visible light can be ascribed to the trapping of electrons at interior sites of the carbon-doped titania between the valence and conduction bands in the titania band structure, and is able to activated by visible light of a wavelength of up to 550 nm. The photocatalytic activity of the carbon-doped TiO₂ nanoparticles was evaluated by examining the decomposition of phenol by irradiation with artificial solar light (>420 nm) and the results were compared with those using Degussa P25, a commercially available titania nanomaterial.     

Preparation of cerium and nitrogen co-doped titania hollow spheres with enhanced visible light photocatalytic performance

N,Ce-codoped titania hollow spheres were prepared using carbon spheres as template and using N,Ce-codoped titania nanoparticles as building blocks. The N,Ce-codoped titania nanoparticles were synthesized at low temperature. The prepared hollow spheres were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and UV-Vis diffuse reflectance spectrum (DRS). The effect of N and Ce content on the physical structure and photocatalytic properties of the as-prepared hollow sphere samples was investigated. The mechanism of photocatalytic degradation of dyes under visible light irradiation was also discussed.     

不同方法制备硫掺杂TiO2及其可见光催化性能研究

采用水热法和焙烧法分别制备了硫掺杂纳米TiO₂,通过扫描电子显微镜、X射线光电子能谱和紫外可见漫反射光谱进行了表征,以水体中的甲基橙（MO）为模拟污染物,研究了硫掺杂纳米TiO₂ 的可见光光催化性能。结果表明,2种不同制备方法得到的硫元素掺杂TiO₂均表现出可见光活性。硫元素在TiO₂中分别取代了O₂和Ti的位置,改变了TiO₂原来的能带结构,形成新的杂质能级,从而使TiO₂ 的吸收区间由紫外拓展到可见光区。     

Mechanochemical Synthesis of Visible-light Induced Photocatalyst with Nitrogen and Carbon Doping

Nitrogen and/or carbon doped titania photocatalysts were prepared by a novel mechanochemical method. The prepared powders possessed two absorption edges around 400 and 540 nm wavelengths and showed excellent photocatalytic ability for nitrogen monoxide oxidation under visible light irradiation. Under the irradiation of visible light of wavelength >510 nm, 37% of nitrogen monoxide could be continuously removed by the carbon and nitrogen co-doped titania prepared by planetary ball milling of P-25 titania-10% hexamethylenetetramine mixture followed by calcination in air at 400?C.     

Nanocolumnar titania thin films uniquely incorporated with carbon for visible light photocatalysis

Carbon-doped or carbon-covered titania can enhance photocatalytic performance under visible light. Here we report the first instance of synergistic effect of the carbon incorporation in anatase titania (TiO_2−xC_x:C) films with both substitutional doping and surface covered characteristics, by reactively co-sputtering Ti metal and graphite targets. The nature of incorporated carbon is characterized by Raman spectroscopy, X-ray photoelectron spectroscopy and transmission electron microscopy. The absorption edge of the carbon incorporated titania thin films shifted from ultraviolet to visible region and directly depended on the carbon content. The photocatalytic performance, e.g., photodegradation of methylene blue (MB), photo-reduction of silver-ions and super hydrophilicity, was greatly enhanced with increasing carbon content. The best photocatalytic activity is obtained in the TiO_2−xC_x:C film of the most carbon concentration about 9.3 at.% with a degradation rate-constant of 0.108 h⁻¹ for MB under visible-light illumination.     

Efficient gas phase photodecomposition of acetone by Ru-doped Titania

Nanocrystalline titania particles doped with ruthenium oxide have been prepared by homogenous hydrolysis of TiOSO₄ in aqueous solutions in the presence of urea. The synthesized particles were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), High Resolution Transmission Electron Microscopy (HRTEM), Selected Area Electron Diffraction (SAED) and surface area (BET) and porosity determination (BJH). The photocatalytic activity of Ru-doped titania samples was determined in the gas phase by decomposition of acetone during irradiation at 365 nm and 400 nm. The Ru-doped titania samples demonstrated enhanced photocatalytic activity under visible light. Ruthenium oxide causes the anatase to rutile transformation to occur at lower temperatures and decreasing of band-gap energy of Ru-doped samples.     

Fe~(3+)掺杂提高二氧化钛的光催化活性

采用沉淀-水热的方法制备了Fe3+掺杂的TiO2光催化剂,通过XRD、Raman、XPS、UV-DRS等对催化剂的结构、光学吸收性质等进行了表征,并以罗丹明B为目标污染物对可见光催化活性进行了测试。实验结果表明:所制备的TiO2光催化剂为锐钛矿相结构;Fe3+的掺杂使得TiO2的初始吸收边明显向可见光区域拓宽,并且增强了TiO2在可见光区域的吸收;Fe3+掺杂后TiO2的可见光催化活性显著提高,以掺杂浓度为0.5%的TiO2光催化效果最好,在可见光下6h内可将罗丹明B溶液完全降解,降解率是未掺杂TiO2的4倍。     

氮掺杂二氧化钛光催化剂的研究进展

纯纳米二氧化钛禁带较宽,只能在紫外光下激发。拓宽二氧化钛的光谱响应范围,实现可见光激发,是二氧化钛基光催化材料面临的主要问题。氮掺杂二氧化钛具有良好的可见光催化活性,是具有可见光响应的二氧化钛基光催化材料的典型代表,近十年来受到了广泛关注。本文综述氮掺杂二氧化钛可见光响应机理和提高光催化活性方面的研究进展,提出今后值得关注与研究的方向。     

用水量对溶胶-凝胶法制备氮掺杂纳米二氧化钛的影响

采用两种用水量的溶胶-凝胶工艺制备了氮掺杂二氧化钛(N-TiO2)纳米颗粒粉末,对样品进行了X射线衍射、透射电子显微镜、X射线光电子能谱及紫外-可见漫反射谱分析,并以甲基橙的光催化降解实验研究了样品的可见光催化性能。结果表明:采用用水多的溶胶-凝胶工艺可获得可见光催化活性高的N-TiO2,且N-TiO2的颗粒粒径较小;由于溶胶中过量的N掺杂剂可在N-TiO2前驱体凝胶离心分离时被去除,可进行较低温度的煅烧,易于获得N掺杂浓度较高的N-TiO2。另外,采用用水多的工艺时,氮掺杂剂对TiO2颗粒的氮化及凝胶化过程也有很大的影响,有些含氮化合物作为掺杂剂可能会明显降低N-TiO2的可见光催化活性。