C@CdS/埃洛石纳米管复合光催化剂一步热解法的制备及光降解性能(英文)

通过一步热解法合成了一种新的复合光催化剂C@CdS/埃洛石纳米管(HNTs).用扫描电镜(SEM),X射线能谱(EDS),透射电镜(TEM),X射线衍射(XRD),紫外-可见漫反射光谱(UV-Vis DRS),傅里叶变换红外(FT-IR)光谱,比表面积和拉曼光谱(RS)对材料进行表征.利用可见光下降解四环素探究了C@CdS/HNTs的光催化活性.结果表明,所制备的不同热解温度的样品中,400°C热解温度下的样品降解四环素效果最好,可见光照射60 min降解率能达到86%.此外,得益于碳层、CdS和HNTs的共同作用,光催化剂展示了很好的稳定性.放置一年对催化活性没有任何影响,并且经过三次循环实验,光催化剂活性没有很大变化.最后讨论了光催化剂的制备机理,并且对光催化降解过程的中间产物进行了分析.     

Ag_3PO_4/BiVO_4复合光催化剂的制备及可见光催化降解染料(英文)

结合回流法和原位沉淀法成功制备磷酸银/矾酸铋(Ag3PO4/BiVO4)复合光催化剂.通过X射线衍射(XRD)、场发射扫描电子显微镜(FESEM)、能量色散X射线光谱(EDS)、紫外-可见漫反射光谱(UV-Vis DRS)及光致发光(PL)光谱对制备样品进行表征.XRD和FESEM结果表明成功制备Ag3PO4/BiVO4复合光催化剂.采用节能发光二极管灯(LED)作为可见光光源,在低消耗光催化系统中评价制备样品可见光催化降解染料的活性.当Ag3PO4和BiVO4的组成摩尔比为1:3时,复合Ag3PO4/BiVO4光催化剂呈现出高于纯相Ag3PO4的催化活性,可减少Ag3PO4的使用量.Ag3PO4/BiVO4复合光催化剂在中性溶液中表现出高活性,同时证实其对阳离子染料的光催化降解效果强于阴离子染料.在Ag3PO4/BiVO4系统中,超氧自由基和空穴是主要的活性物种.经过三次循环利用,Ag3PO4/BiVO4复合催化剂的可见光催化活性表现出不同程度的降低,归因于降解过程中产生金属银.     

Ag@AgCl修饰TiO2-xCx光催化剂的制备及其可见光降解污染物性能

以钛酸丁酯和葡萄糖为原料用水热法制备了碳掺杂二氧化钛,再进一步对其进行Ag@AgCl表面修饰.用X射线衍射(XRD),X射线光电子能谱(XPS),透射电镜(TEM),BET比表面仪和紫外-可见(UV-Vis)漫反射光谱等手段对样品进行测试表征;在可见光辐射下(λ＞420 nm),以甲基橙和苯酚溶液的光催化降解实验来评价样品的活性.结果表明:经Ag@AgCl修饰后,样品的粒径增大,比表面积减小,对可见光的响应增强;可见光光催化效率有大幅度提高,对甲基橙和苯酚的降解效率分别是修饰前的5.5和3.4倍,且光催化剂经三次循环使用后活性基本保持不变.     

不同前驱体制备氮掺杂二氧化钛及其光催化性能比较

在氨气气氛中和不同温度下焙烧纳米管钛酸和商业Degussa-P25,得到两系列可见光响应型氮掺杂二氧化钛光催化剂.采用高分辨透射电子显微镜、紫外-可见漫反射光谱仪和X射线衍射仪对两系列样品的形貌、光谱吸收和晶体结构等物理化学性质进行了表征和比较.通过可见光光催化氧化丙烯评价系统对两系列样品的活性进行了评价.结果表明,600℃处理纳米管钛酸得到的催化剂可见光催化活性最好,是相同条件下处理Degussa-P25得到的催化剂(N-P25)活性的3.3倍.研究表明,纳米管钛酸是制备可见光响应型光催化剂较好的前驱体.     

可见光响应光催化剂Ag/AgCl@NH2-UiO-66的制备及其光催化性能

采用气相扩散-沉积-光还原法制备了可见光响应复合光催化剂Ag/AgCl@NH_2-UiO-66。通过X射线衍射(XRD)、电子扫描显微镜(SEM)、X射线能谱(EDS)、紫外可见漫反射光谱及X射线光电子能谱(XPS)等对催化剂的结构进行了表征。结果表明Ag/AgCl@NH_2-UiO-66具有优良的光催化活性,可见光条件下(λ≥420nm)对20mg·L~(-1)罗丹明的降解效率14min即可达到98%。     

可见光响应光催化剂Ag/AgCl@NH2-UiO-66的制备及其光催化性能

采用气相扩散-沉积-光还原法制备了可见光响应复合光催化剂Ag/AgCl@NH₂-UiO-66.通过X射线衍射(XRD)、电子扫描显微镜(SEM)、X射线能谱(EDS)、紫外可见漫反射光谱及X射线光电子能谱(XPS)等对催化剂的结构进行了表征.结果表明Ag/AgCl@NH₂-UiO-66具有优良的光催化活性,可见光条件下(λ≥420 nm)对20 mg·L^-1罗丹明的降解效率14 min即可达到98%.     

钯氮共掺杂TiO2的制备与表征及其可见光催化活性

在空气气氛和N₂中热处理表面均匀分散有尿素和氯化钯的纳米管钛酸,制备了两个系列Pd/N共掺杂的TiO₂光催化剂,并对所得样品进行了X射线衍射、透射电镜、X射线光电子能谱、紫外-可见漫反射光谱、荧光光谱和电子自旋共振等表征.结果表明,焙烧气氛对样品的形貌、晶体结构、光谱吸收、生成的氧空位浓度和可见光光催化性能的影响很大,其中在空气气氛中制备的样品光催化性能优于在N₂中制备的样品.在可见光(λ≥420nm)照射下,以丙烯为模型污染物考察了样品的光催化活性,发现在空气中400℃下焙烧的样品具有最佳的可见光催化活性.另外,讨论了Pd/N共掺杂TiO₂光催化剂具有可见光响应的机理,认为掺杂的Pd/N元素和制备过程中生成的氧空位是影响可见光催化性能的重要因素.     

可循环使用的Sn-TiO_2/聚噻吩纳米杂化材料用于可见光下降解有机污染物（英文）

采用改进的溶胶-凝胶法在低温制备了Sn-Ti O2/聚噻吩纳米杂化材料(SPNH),运用X射线衍射(XRD)、扫描电镜、X射线光电子能谱(XPS)、红外光谱(IR)、紫外-可见光漫反射光谱(UV-DRS)和BET比表面积分析对所制样品进行了表征.XRD结果证实聚噻吩(PTh)对Ti O2晶相结构没有影响.IR和UV-DRS结果表明,在掺杂的金属氧化物与PTh的纳米杂化和结合过程中,PTh表面与金属氧化物之间存在相互作用(类似核壳结构).XPS结果显示,纳米杂化材料中存在Sn4+以及PTh与Ti O2各自所含的元素.催化剂表面吸附污染物结果发现,SPNH的吸附容量高于Sn-Ti O2纳米粒子(STN).在可见光下降解有机污染物硝基苯(NB)和孔雀绿(MG)的反应中,SPNH表现出比单纯STN更高的光催化活性和稳定性.由于STN上存在聚噻吩,使得样品表面吸附NB(24%)和MG(21%)的能力增加,从而导致更高的光催化收率.考察了该光催化剂在可见光下重复使用5次时的光催化活性,未见PTh的消耗和降解.这些高光催化活性的SPNH材料有望在工业水净化中用作光催化剂.     

La掺杂Bi2O3的制备、表征与可见光催化活性

采用浸渍法制备了La掺杂Bi2O3(La-Bi2O3)光催化剂,利用X射线荧光光谱(XRF)、X射线衍射(XRD)、扫描电子显微镜(SEM)、傅立叶变换红外光谱(FT-IR)、X射线光电子能谱(XPS)、紫外-可见吸收光谱(UV-Vis)和光致发光谱(PL)等分析测试手段对样品的La掺杂量、晶体结构和光谱特征等进行了表征,并以2,4-二氯苯酚(2,4-DCP)水溶液的降解作为探针反应,考察了样品的可见光催化性能.结果表明,适量的La掺杂能有效抑制Bi2O3由四方相向单斜相转变,并将光吸收范围拓展到550 nm以上.掺杂的La可取代Bi2O3晶格中部分Bi,形成Bi—O—La键,并生成了少量镧铋复合氧化物(La0.176Bi0.824O1.5),它们的存在能有效抑制光生电子-空穴对的复合,从而提高光催化量子产率.可见光照射下2,4-DCP的光催化降解实验表明,La-Bi2O3具有良好的可见光催化性能,并且当La的掺杂量为3%(摩尔分数)时,催化剂的可见光催化效率最高.     

Pt/BiOCl纳米片的制备、表征及其光催化性能

采用光化学沉积法制备了一系列不同Pt含量的新型Pt/BiOCl纳米片光催化剂,运用N2物理吸附-脱附、X射线粉末衍射、扫描电镜、透射电镜、X射线光电子能谱、光致发光光谱、紫外-可见漫反射光谱等手段对Pt/BiOCl进行了表征,并以λ=254nm的紫外灯和钨灯为光源,考察了Pt含量对Pt/BiOCl光催化降解酸性橙II活性的影响.结果表明,沉积的Pt对BiOCl样品比表面积的影响不大,但可有效增强催化剂对可见光的吸收能力,显著抑制光生电子与空穴的复合.当Pt含量为1%~2%时,能大幅度提高紫外光下BiOCl催化降解染料的活性,并产生可见光活性.这是由于Pt/BiOCl具有一定的可见光吸收能力,产生了Pt纳米粒子的等离子体光催化作用.     

可见光下具有高光子效应和光催化活性的CuS-石墨烯氧化物/TiO2复合材料的制备（英文）

CuS-graphene oxide/TiO2 composites were prepared using a sol-gel method to improve the photocatalytic performance of the photocatalyst. The composites were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray analysis, and transmission electron microscopy. The photocatalytic activities were examined by the degradation of methylene blue (MB) under visible-light irradiation. The photodegradation of MB under visible-light irradiation reached 90.1% after 120 min. The kinetics of MB degradation was plotted alongside the values calculated from the Langmuir-Hinshelwood equation. The CuS-graphene oxide/TiO2 sample prepared using 0.2 mol of TiO2 showed the best photocatalytic activity. This was attributed to a cooperative reaction as a result of increased photoabsorption by graphene oxide and an increased photocatalytic effect by CuS.     

铁掺杂羟基锆柱撑钛酸盐的制备及光催化性能

采用单分子层剥离-重堆积技术将掺铁的聚合羟基锆离子嵌入到钛酸盐层间, 制得了铁掺杂羟基锆柱撑钛酸盐复合材料(FZPT), 考察了Fe掺杂对Zr柱撑钛酸盐复合材料(ZPT)形成及光催化活性的影响. 利用X射线衍射仪(XRD)、 扫描电子显微镜(SEM)、 透射电子显微镜(TEM)、 紫外-可见漫反射光谱仪(UV-Vis DRS)和吸附分析仪等对材料进行了表征. 结果表明, 当铁的掺入量小于锆质量的10%时, 复合柱撑材料FZPT的孔径和比表面积随着Fe掺入量的增加而增大, 继续增加则结果相反. 紫外-可见光催化降解亚甲基蓝(MB)实验结果表明, FZPT催化活性均高于ZPT, 可能与掺杂后材料形成介孔结构与比表面积增大有关. 样品FZPT-0.20的可见光催化活性相对较好, 表明材料的光催化活性与掺杂后柱撑材料中含铁客体与主体间的电子耦合作用有关.     

Improved visible light photocatalytic activity of titania loaded with silver on discoloration of a heterocyclic aromatic chemical dye solution

The photocatalytic activity of silver deposited Degussa P25 titanium dioxide (Ag-DP25) in the photodegradation of methylene blue (MB) was investigated. The as-prepared materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (DRS), infrared spectra and surface photovoltage spectroscopy (SPS) techniques. The obtained results show that the silver dopant could effectively inhibit the recombination of the photoinduced electron and holes, improving the absorption capability for visible light of photocatalyst and leading to increased surface OH group density. The degradation experiment reveals that the catalytic property of Ag-DP25 in the degradation of MB dye is more efficient than that of commercially available Degussa P25 TiO₂ (DP25) samples under visible-light irradiation. Besides, degradation kinetics of MB dye can, be well described by Langmuir-Hinshelwood equation and shows pseudo-first order law.     

Bi_(20)TiO_(32)/聚丙烯腈复合纳米纤维的制备及其对异丙隆的光催化降解性能

采用溶剂热法制备了可见光响应型光催化剂Bi_(20)TiO_(32),为了实现该光催化剂的固定化负载,进一步以Bi_(20)TiO_(32)和聚丙烯腈(PAN)为原料,通过同轴静电纺丝法制备了不同光催化剂含量的Bi_(20)TiO_(32)/PAN复合纳米纤维。通过这一途径一方面可以便于光催化剂的回收利用,另一方面纳米纤维结构可以提高光催化剂与有机污染物反应的接触面积。采用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、紫外-可见漫反射光谱(UV-Vis DRS)和氮气吸附-脱附法对样品的物相组成、形貌结构、光谱吸收和比表面积等进行表征。研究了在可见光照射下Bi_(20)TiO_(32)/PAN复合纳米纤维膜对苯脲类农药异丙隆的光催化降解性能。结果显示,制备的Bi_(20)TiO_(32)光催化剂禁带宽度为2.35 eV,属于典型的可见光响应型光催化剂。制备的Bi_(20)TiO_(32)/PAN复合纳米纤维直径在600~700 nm,Bi_(20)TiO_(32)可以在纳米纤维表面均匀负载,复合纳米纤维膜对可见光具有明显的响应性,对异丙隆具有很好的光催化降解效果,其中光催化剂质量分数为25.7%的样品S3对异丙隆的降解率最高可达到87%。这一研究表明,通过同轴静电纺丝法将光催化剂负载于有机纳米纤维表面,可以保持光催化剂原有光催化效果,是实现光催化剂固定化一条较好的途径。     

氮掺杂石墨烯负载的硫化镉空心球纳米复合材料的光催化性能

通过无模板法一步合成了一种新型N掺杂石墨烯负载的CdS空心球复合材料. 采用X射线衍射、透射电镜、红外光谱、紫外-可见光谱、N₂吸附-脱附、荧光光谱和X射线光电子能谱等技术对该材料进行了表征, 并在可见光照射下测试了其在降解亚甲基蓝和水杨酸中的光催化性能. 结果表明, 相对于氧化石墨烯负载硫化镉空心球和单独的硫化镉空心球, 氮掺杂石墨烯负载的硫化镉空心球具有更高的光催化活性和稳定性. 这是由于氮掺杂的石墨烯能充当优异的电子受体和传输体, 从而抑制了载流子的复合. 另外发现, 羟基自由基是可见光下降解亚甲基蓝的主要活性物种.     

Influence and Characterization of Acidity on Fine Silicon Powder Immobilized Photocatalyst

TiO2 photocatalyst was supported with tetrabutyl titanate sol as precursor and fine silicon powder obtained from ferroalloys factory as carder to discuss the influence of pH value of gel precursor on microstructure and activity of photocatalyst in the process of synthesizing nano-TiO2 by using sol-gel method, the purpose of which is to provide fundamental data for the recycle of photocatalytic material. Under the irradiation of ultraviolet light, the photocatalytic degradation rate of methyl orange solution was used to characterize the photocatalytic activity of the sample. The specific surface area of the sample was tested by N2 desorption method, crystal form of TiO2 was analyzed by X-ray powder diffraction, and the microtopography of the sample was observed by scanning electron microscopy. The experimental results showed that the acidity of gel precursor could greatly affect the specific surface area and photocatalytic activity of the photocatalyst, and the optimum pH value of the precursor was determined as 2.0, and at this time the specific surface area of photocatalyst could reach 34.0 m^2/g. In the sample, the proporticn of anatase to rutile is 7：3, which makes l0 mg·L^-1 methyl orange solution fade after irradiation by 15W ultraviolet light for 24 h, and the degradation rate might be up to 98.1%.     

Synthesis of Gd-N Codoped Porous TiO2 Photocatalyst and Its Enhanced Photocatalytic Activities

Visible-light-active Gd-N codoped porous TiO₂(Gd-N-TiO₂) photocatalyst was fabricated by an evapora-tion-induced self-assembly route using surfactants as structure-directed agents. As-prepared samples were characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy(TEM), X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller(BET) method, and ultraviolet-visible absorption spectroscopy. The results indicated that synergistic reaction occurred when codoping with Gd³⁺ and N, which enhanced the light absorption properties of TiO₂. Irregular worm-like particles with wide interparticle spaces were clearly observed by TEM. The average particle size of Gd-N-TiO₂ decreased to ca. 8 nm because co-doping inhibited the particles growth significantly. Thus, the specific surface area of Gd-N-TiO₂(198.7 m²/g) was higher than that of Degussa P25 TiO₂(50 m²/g). Gd-N-TiO₂ exhibited a high photocatalytic activity toward methyl orange degradation under UV-Vis or visible-light irradiation. The Gd-N-TiO₂ catalyst also presented a stable performance without losing activity after four successive photocatalytic experiments. The facile synthesis and excellent activity of Gd-N-TiO₂ indicated its great potential as industrial catalysts for wastewater treatment.     

Visible-light-induced photocatalytic performances of ZnO-CuO nanocomposites for degradation of 2,4-dichlorophenol

Nanostructured ZnO and CuO, and coupled oxides, i.e., ZnCu, Zn2Cu, and ZnCu2, with ZnO:CuO molar ratios of 1:1, 2:1, and 1:2, respectively, were successfully prepared through a simple, one-step, mi-crowave-assisted urea–nitrate combustion synthesis, without the use of organic solvents or surfac-tants. The prepared samples were characterized using X-ray diffraction, X-ray photoelectron spec-troscopy, scanning electron microscopy, energy-dispersive X-ray analysis, transmission electron microscopy, Fourier-transform infrared spectroscopy, diffuse reflectance spectroscopy, and photo-luminescence spectroscopy. The optical absorption of ZnO extended into the visible region after CuO loading. The photocatalytic activities of ZnO, CuO, and the coupled oxides were evaluated based on photodegradation of 2,4-dichlorophenol under visible-light irradiation. The coupled metal oxide Zn2Cu showed the best photocatalytic activity;this was mainly attributed to the extended photore-sponsive range and the increased charge separation rate in the nanocomposite. The photocatalytic degradation process obeyed pseudo-first-order kinetics. The results suggest that the coupled metal oxide Zn2Cu has potential applications as an efficient catalytic material with high efficiency and recyclability for the photocatalytic degradation of organic pollutants in aqueous solution under visible-light irradiation.     

可循环使用的Sn-TiO2/聚噻吩纳米杂化材料用于可见光下降解有机污染物

采用改进的溶胶-凝胶法在低温制备了Sn-TiO2/聚噻吩纳米杂化材料(SPNH),运用X射线衍射(XRD)、扫描电镜、X射线光电子能谱(XPS)、红外光谱(IR)、紫外-可见光漫反射光谱(UV-DRS)和BET比表面积分析对所制样品进行了表征。 XRD结果证实聚噻吩(PTh)对TiO2晶相结构没有影响。 IR和UV-DRS结果表明,在掺杂的金属氧化物与PTh的纳米杂化和结合过程中, PTh表面与金属氧化物之间存在相互作用(类似核壳结构)。 XPS结果显示,纳米杂化材料中存在Sn4+以及PTh与TiO2各自所含的元素。催化剂表面吸附污染物结果发现, SPNH的吸附容量高于Sn-TiO2纳米粒子(STN)。在可见光下降解有机污染物硝基苯(NB)和孔雀绿(MG)的反应中, SPNH表现出比单纯STN更高的光催化活性和稳定性。由于STN上存在聚噻吩,使得样品表面吸附NB(24%)和MG(21%)的能力增加,从而导致更高的光催化收率。考察了该光催化剂在可见光下重复使用5次时的光催化活性,未见PTh的消耗和降解。这些高光催化活性的SPNH材料有望在工业水净化中用作光催化剂。     

Preparation and characterization of Ag@AgCl-doped fly ash cenospheres for photocatalytic applications

A plasmonic photocatalyst composite based on Ag@AgCl and fly ash cenospheres was successfully prepared through a two-step method. X-ray diffraction analysis, scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy, and diffuse reflectance ultraviolet–visible spectroscopy were used to determine the structure and optical properties of the Ag@AgCl-doped fly ash cenospheres (denoted Ag@AgCl/FAC). SEM micrographs showed that Ag@AgCl was well deposited on the surface of the fly ash cenospheres. Photocatalytic experiment results showed that the degradation ratio increased with increasing dosage of Ag@AgCl/fly ash cenospheres; proper concentration of pollutant was important for the photocatalytic reaction for given amount of catalyst. Moreover, improved degradation of rhodamine B was observed at acidic conditions under visible-light irradiation. This excellent catalytic ability is mainly attributed to the formation of Ag nanoparticles on the surface of the fly ash cenospheres and the high separation efficiency of photoelectron–hole pairs.