共查询到20条相似文献,搜索用时 15 毫秒
1.
《Ceramics International》2023,49(16):26548-26557
A novel chiral Ag@Ag3PO4-NaDC composite was synthesized by chiral induction. SEM, XRD, CD spectrum, FTIR, UV–vis and XPS were used to study the physical and chemical properties of the materials, and the photocatalytic oxidation ability was evaluated with methyl orange as the target pollutant. The results show that the introduction of chirality can obviously promote the light absorption ability, broaden the band gap, enhance the oxidation ability, promote the separation of electrons and holes, greatly enhance the plasma resonance effect of silver nanoparticles, and promote the synergistic effect between silver nanoparticles and silver phosphate. Compared with Ag@Ag3PO4, the catalytic degradation ability of chiral Ag@Ag3PO4-NaDC is improved by more than 60%. Therefore, the chiral Ag@Ag3PO4-NaDC composite exhibits excellent photocatalytic performance. In the degradation of methyl orange by Ag@Ag3PO4-NaDC, a large amount of ·O2- and h+ were formed on the surface, which was the main reason for the oxidation ability. 相似文献
2.
Electrochemically assisted photocatalytic degradation of methyl orange using anodized titanium dioxide nanotubes 总被引:1,自引:0,他引:1
Yon S. Sohn York R. Smith Manoranjan Misra Vaidyanathan Subramanian 《Applied catalysis. B, Environmental》2008,84(3-4):372-378
The TiO2 nanotubes have demonstrated potential in the photoelectrocatalytic degradation of methyl orange dye (MO). TiO2 nanotubes were prepared using anodization of titanium foils in phosphoric acid (PA) and ethylene glycol (EG) by mechanical stirring and ultrasonic method. The TiO2 nanotubes prepared in EG under ultrasound followed by annealing in nitrogen atmosphere showed higher activity towards dye degradation as compared to the stirring method. Dye degradation shows improved activity under an external bias compared to degradation performed in the absence of an external bias. An increase in the external bias from +0.0 to +0.1 V versus calomel electrode (SCE) is sufficient to improve the degradation rates of MO from 22% to 57% within the first 10 min. At +0.1 V, a complete degradation of 40 μM MO is observed within 30 min. The addition of oxidants such as oxygen and hydrogen peroxide demonstrate improvement in the MO degradation. 相似文献
3.
采用沉淀法制备了不同掺杂量的Zn/TiO2催化剂,以光催化降解甲基橙为探针反应,考察其光催化活性,并采用紫外漫反射和X射线衍射对其进行结构表征。研究结果表明,Zn的掺杂量对催化剂活性影响较大,最佳掺杂物质的量分数为1.5%;催化剂的紫外漫反射微分曲线的峰值变化与其活性变化一致,1.5%(物质的量分数) Zn/TiO2的微分峰值最大。X射线衍射分析表明,少量Zn高度分散在TiO2晶格中。Zn掺杂物质的量分数1.5%时,添加2 g·L-1的Zn/TiO2催化剂,甲基橙降解的最佳条件:pH=3,浓度15 mg·L-1,降解率最高达98.6%。 相似文献
4.
《Ceramics International》2020,46(11):19038-19045
Waelz slag, which is a Fe-bearing hazardous waste, was applied as the raw material in the synthesis of M-Fe3O4@Fe2O3 (M = Al, Zn, Cu, and Mn) nanoparticles, which are potential photocatalysts. Through acidolysis, 97.23% of Fe and most of the valuable metals were extracted from this slag. Using sol-gel processes, designed Fe3O4@Fe2O3 nanoparticles doped with multiple elements were systematically synthesised and characterised using X-ray diffraction, field emission scanning electron microscopy, electron diffraction spectroscopy, transmission electron microscopy, and Brunauer–Emmett–Teller analysis. The photocatalytic activities of the synthesised particles and undoped Fe2O3 nanoparticles were compared through photocatalytic methyl orange degradation experiments under UV and simulated solar light. The results indicated that all of the slag-derived nanoparticles gave improved photocatalytic performances compared to the undoped sample, and the M-Fe3O4@Fe2O3 (M = Al, Zn, and Cu) sample exhibited the best photocatalytic activity. The enhancement can be attributed to grain refinement, doping, and the formation of a typical Fe3O4@Fe2O3 core-shell structure. 相似文献
5.
以Bi(NO_3)5·5H_2O、Na Br、H_2WO_4为原料,采用一步水热合成法合成不同n(W)∶n(Br)的WO_3/BiOBr复合催化剂,并通过SEM和TEM对催化剂进行表征分析。以甲基橙为探针污染物,考察前驱液pH、水热温度、水热时间和n(W)∶n(Br)对WO_3/BiOBr复合催化剂活性的影响。结果表明,在pH为10.2、100℃水热时间6 h合成n(W)∶n(Br)为0.02的WO_3/BiOBr复合催化剂活性最好,光照120 min后,对目标污染物的降解率达99.39%,较BiOBr催化剂(合成条件为原始pH值,100℃水热反应6 h)提高了30.85%。采用水热合成法制备的WO_3/BiOBr复合催化剂具有良好的可见光活性。 相似文献
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采用原位聚合法制备了一系列不同质量比m(Th)/m(Tb掺杂介孔TiO2)的复合光催化剂(其中Th为噻吩),采用XRD、FTIR、荧光光谱(PL)、场发射透射电镜(FETEM)和X射线光电子能谱(XPS)对复合光催化剂进行了表征。结果表明,复合粒子上的聚噻吩骨架中S原子与TiO2粒子间存在相互作用。以罗丹明B为模型降解物,研究了不同比例复合光催化剂在可见光下的光催化性能,其中m(Th)/m(Tb掺杂介孔TiO2)=1/10复合光催化剂光催化性能最好。在可见光照射下4 h,脱色率达到82.4%。这是由于Tb掺杂介孔TiO2与PTh(聚噻吩)之间的协同作用,拓宽了TiO2纳米粒子的光响应范围,提高了光生电子和空穴的分离效率,从而有效提高了其光催化性能。 相似文献
8.
燃烧法制备纳米ZnO及光催化降解甲基橙的研究 总被引:2,自引:0,他引:2
分别以甘氨酸和柠檬酸为燃料,Zn(NO3)2为氧化剂,采用燃烧法制备纳米ZnO粉体并采用模拟太阳光进行甲基橙光催化降解研究。XRD和SEM表征样品表明,燃烧法能简单、快速制备纳米ZnO粉体。研究表明,燃烧剂和氧化剂的配比以及反应温度对制备的纳米ZnO降解甲基橙效果有较大影响。Zn(NO3)2与甘氨酸之比为0.2~0.5(物质的量比),反应温度为5000C;Zn(NO3)2与柠檬酸之比为1.5,反应温度为600℃进行反应制备得到的纳米ZnO降解甲基橙效果较好。降解实验的结果表明,纳米ZnO能有效地光催化降解甲基橙染料。以柠檬酸为燃料制备的ZnO样品,在1h内对10mg·L^-1甲基橙溶液的降解率为90%。 相似文献
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《Ceramics International》2023,49(4):6213-6221
Researchers have attempted to developing high-efficiency catalysts for photocatalytic hydrogen evolution and organic pollution elimination simultaneously to alleviate the issues of energy shortage and water pollution. In this work, we fabricated 3D interconnected porous boron doped polymeric g-C3N4 catalysts with efficient photocatalytic activity for hydrogen evolution and dye contaminant elimination under visible-light irradiation. The as-fabricated catalysts exhibited significantly enhanced hydrogen evolution (4.37 mmol g ?1 h?1) and RhB contaminant elimination (96.37%) activity. Based on characterization and photocatalytic tests, an enhanced mechanism of the superior photocatalytic performance was proposed: 3D interconnected porous structure and B-doping have a synergistic effect on the greatly improved photocatalytic activity. The 3D interconnected structures endowed g-C3N4 with a higher specific surface area and abundant active sites and improved the capacity of rapid absorption to facilitate the photocatalytic process. B doping provided enhanced visible-light absorption capacity and a narrowed bandgap and served as a “highway” for electron-hole pairs to facilitate migration and separation and suppress the combination of photogenerated carriers. Besides, the possible mechanism of enhanced photocatalytic performance was elucidated according to the results of characterization measurements and active species analysis. 相似文献
11.
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. 相似文献
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采用金属钇掺杂改性,以钛酸四丁酯为主要原料,在室温下,利用溶胶-凝胶法制备了Y3+掺杂纳米TiO2光催化剂,通过X射线衍射分析(XRD)方法分析其改性机制;掺钇纳米TiO2光催化剂经太阳光照射后,用分光光度计测量光催化降解反应后甲基橙溶液浓度的变化,考察其光催化活性;研究了掺杂量和焙烧温度对光催化活性的影响。结果表明,Y3+掺杂能有效地抑制锐钛矿型TiO2向金红石型TiO2的转化,可使纳米TiO2的衍射峰宽化,粒径从80.5 nm降低到42.15 nm,掺杂量为1.2%,焙烧温度在400℃左右时,能够有效地提高TiO2光催化剂光催化活性。 相似文献
14.
K. V. Divya Lakshmi T. Siva Rao J. Swathi Padmaja I. Manga Raju M. Ravi Kumar 《中国化学工程学报》2019,27(7):1630-1641
Undoped and Ni–S co-doped mesoporous TiO_2 nano materials were synthesized by using sol–gel method.The characteristic features of as prepared catalyst samples were investigated using various advanced spectroscopic and analytical techniques. The characterization results of the samples revealed that all the samples exhibited anatase phase(XRD), decreasing band gap(2.68 eV)(UV–Vis-DRS), small particle size(9.2 nm)(TEM), high surface area(142.156 m~2·g~(-1))(BET), particles with spherical shape and smooth morphology(SEM); there is a frequency shift observed for co-doped sample(FT-IR) and the elemental composition electronic states and position of the doped elements(Ni and S) in the TiO_2 lattice analyzed by XPS and EDX. These results supported the photocatalytic degradation of Bismarck Brown Red(BBR)achieved with in 110 min and also exhibited the antibacterial activity on Staphylococcus aureus(MTCC-3160), Pseudomonas fluorescence(MTCC-1688) under visible light irradiation. 相似文献
15.
微波水热法制备稀土元素铒掺杂TiO_2光催化剂及光催化活性 总被引:1,自引:0,他引:1
采用微波水热法和溶胶-凝胶法制备稀土元素Er掺杂TiO_2光催化剂TiO_2-Er,以甲基橙溶液为模拟污染物,在微波辐射-紫外光照(MW-UV)和太阳光照条件下,考察TiO_2-Er光催化剂的光催化降解活性。分别用N_2吸附-脱附、ICP-AES和PL光谱分析对TiO_2-Er光催化剂进行结构测试和表征。结果表明,Er掺杂能显著提高TiO_2光催化剂光催化活性,微波水热法制备的TiO_2-Er光催化剂具有较高的光催化活性;微波水热法和溶胶-凝胶法制备的TiO_2-Er光催化剂微波辐射-紫外光照50 min,甲基橙降解率分别为100%和98.5%,太阳光照4 h,甲基橙降解率分别为99.0%和97.5%。微波水热法具有晶化时间短和元素掺杂均匀的优点,制备的TiO_2-Er光催化剂具有形貌均匀、孔径较大、孔分布均匀和比表面积较大等特点,且Er掺杂能抑制光生e~-/h~+复合,使光生e~-/h~+的分离效率得到提高,有利于光催化活性的提高。 相似文献
16.
《Ceramics International》2016,42(5):5979-5984
Cu2O/Na-bentonite (Cu2O/NB) composites were firstly synthesized by a simple deposition method. The morphology and composition of the prepared catalysts were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FT-IR) spectroscopy, Brunauer–Emmett–Teller (BET) specific surface area. The results show that the Cu2O microparticles can be immobilized on the surface of the NB. Visible-light photocatalytic properties of the Cu2O/NB composites were evaluated using methyl orange (MO) as a model pollutant and the effects of various experimental factors on MO decolorization were investigated. Cu2O/NB composites demonstrated a much higher photocatalytic activity than the pure Cu2O particles under similar experimental conditions. 相似文献
17.
《Ceramics International》2016,42(13):14743-14748
Bi-doped α-SnWO4 porous spheres assembled by thin plates were prepared by a simple hydrothermal process without any template. The effects of Bi3+ ions on the microstructure and photocatalytic activity of α-SnWO4 were investigated. The doping of Bi can induce a shape transformation from nanoplates of pure α-SnWO4 to hierarchical spheres of Bi-doped samples. The photocatalytic activities of the as-prepared samples were evaluated by photocatalytic de-colorization of methyl orange (MO) under visible light irradiation. Bi-doped α-SnWO4 samples exhibit better photocatalytic property than pure α-SnWO4, and the optimal Bi-doping concentration is around 0.5 at%. The enhanced photocatalytic properties of Bi-doped α-SnWO4 spheres can be ascribed to the porous hierarchical structure and the introduction of defects induced by Bi-doping, which improve visible-light absorption and allow the efficient charge separation of the photogenerated electron-hole pairs. Bi-doped α-SnWO4 has a great potential in industrial water treatment due to its satisfactory recyclability and stability. 相似文献
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《Journal of Industrial and Engineering Chemistry》2014,20(6):4102-4107
Ce, N codoped TiO2 nano-particles were fabricated through sol–gel strategy in the absence of water. Results revealed that Ce was not implanted into the lattice of TiO2 and existed as the forms of small cluster CeO2 which uniformly diffused onto the surface or interstitial site of TiO2, while N dopants were successfully incorporated into the structure of TiO2 by substituting the lattice oxygen atoms and existed as the forms of N–Ti–O bonds, thereby resulting in the formation of impurity level above the valence band of TiO2 and enhancement of visible photocatalytic (PC) performance. The enhanced visible PC mechanism was discussed. 相似文献
20.
Xiao Xinyan Liao Dongliang Zhang Huiping Chen Huanqin 《Frontiers of Chemical Engineering in China》2007,1(2):178-183
TiO2 nano-particles were synthesized by sol-gel technique and characterized by X-ray diffractometer (XRD) and transmission electron
microscope (TEM). Their photocatalytic activities for formaldehyde (FA) and methyl orange (MO) degradation were tested using
degradation rate (η) as an evaluation index. Based on the orthogonal test results, the optimal condition for TiO2 preparation was obtained. Results showed that particle sizes were in the range of 10–40 nm, and that prepared TiO2 had better photocatalytic activity than P25. A simplified model was developed to evaluate the apparent quantum efficiency
(Φ
app) of this photocatalytic reaction system. 相似文献