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1.
A good photocatalyst with high efficiency can be synthesized easily using eco-friendly materials and processes. Our synthesized samples exhibit all of the aforementioned features. In this work, manganese co-doped ZnO at different weight percentages (3, 6, 9, and 15 wt.%) with and without 1.5 wt.% aluminum was synthesized by hydrothermal method, and their photocatalytic activity in aqueous solutions of methyl orange (MO) was investigated under visible light. The structural and optical properties of the samples were characterized using X-ray powder diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis, and diffuse reflectance spectroscopy. In this work, Mn2+ ions in the 9%Mn/ZnO sample and Mn2+, Al3+ ions in the (9%Mn, 1.5%Al)/ZnO sample calcined at 800 °C were replaced instead with some Zn2+ ions in hexagonal wurtzite structures of ZnO. These structures were found next to each other in the form of a hexagonal shape that created 3D-hexagonal-like ZnO nanostructures. Finally, nanoparticles (NPs) and nano hexagonal-like ZnO nanostructures were, respectively, dispersed on the surface of 3D-hexagonal-like structure of 9%Mn/ZnO and (9%Mn, 1.5%Al)/ZnO. Diffuse reflectance spectroscopy analysis showed that the (9%Mn, 1.5%Al)/ZnO sample had more light absorption than 9%Mn/ZnO. However, contrary to our expectations, the 9%Mn/ZnO sample had better decolorization efficiency (94%) after 60 min under visible light, which could be attributed to a significant increase in the level of recombination by the aluminum ions. 相似文献
2.
以大比表面的廉价易得的凹凸棒(palygorskite)为载体,借助带电荷界面的静电调控作用,采用吸附-沉积沉淀方法制备磷酸银/凹凸棒(Ag3PO4/palygorskite)复合催化剂.利用X-射线衍射仪(XRD)、场发射扫描电子显微镜(FE-SEM)、原子吸收光谱(AAS)、紫外可见漫反射光谱(UV-Vis DRS)等技术系统地表征催化剂.之所以能够制备高分散性的凹凸棒负载的磷酸银催化剂,主要是因为凹凸棒具有较大的比表面积、带负电荷界面以及适宜的磷酸根前驱体.以可见光催化脱色降解罗丹明B和氧化降解异丙醇为探针反应,考察复合材料的催化性能.研究表明,与纯磷酸银相比,磷酸银/凹凸棒催化脱色降解罗丹明B和氧化降解异丙醇速率分别提高了2和2.5倍. 相似文献
3.
双环戊二烯苯酚树脂的合成新工艺 总被引:1,自引:0,他引:1
以双环戊二烯(DCPD)和苯酚为原料,甲磺酸为催化剂,合成了双环戊二烯苯酚树脂。适宜工艺条件:苯酚与DCPD摩尔比为5、反应温度120 ℃、反应时间5 h、催化剂质量分数为1.5%,收率89%。所得的双环戊二烯苯酚树脂(DPR)经催化加氢法在H2气压力1.5 MPa、催化剂Pd/Al2O3用量为原料质量分数的0.5%、反应温度80 ℃条件下对树脂进行脱色处理。 得到浅黄色双环戊二烯苯酚树脂,收率89%,经IR和1H NMR表征分析其为目的产物,产物指标达到国际同类产品的质量标准。 相似文献
4.
5.
BiO3对染料的光催化降解性能 总被引:20,自引:1,他引:19
近年来 ,利用半导体材料光催化降解有害污染物已成为比较热门的研究课题之一 [1,2 ] ,因其能有效地利用太阳能并在反应中产生强氧化能力的空穴和羟基自由基 ,因而备受人们的关注 .目前使用较多的是催化活性高 ,稳定性好的 Ti O2 [3] ,但由于其带隙较宽 ( 3.2 e V) ,只能吸收波长 λ≤ 387nm的紫外光 .因此研制新型光催化剂或改善催化效率仍是重要研究课题 .近年来 ,有报道用 Bi2 O3光催化处理含亚硝酸盐废水的实验研究 [4 ] ,结果比较满意 .本研究对 Bi2 O3的制备、表征及其作光催化剂处理各种染料溶液进行实验 ,结果表明 ,Bi2 O3具有较… 相似文献
6.
Photocatalytic decolorization of methyl orange solution with potassium peroxydisulfate 总被引:1,自引:0,他引:1
Zhong Junbo Ma Di Zhao Hong Lian An Li Min Jiao Huang Shengtian Li Jianzhang 《Central European Journal of Chemistry》2008,6(2):245-252
Increasing environmental pollution caused by toxic dyes due to their hazardous nature is a matter of great concern. It has
been generally agreed that methyl orange (MO) can be effectively degraded in aerated K2S2O8 homogeneous reaction system using near-UV irradiation. In this paper photocatalytic degradation of MO solutions with K2S2O8 was investigated, with particular attention on the possible underlying mechanisms. This report has shown decolorization efficiency
of MO increases with the increasing of the dosage of the catalyst. There is no optimal amount of catalyst in our case, where
special attention was paid on the nature of the photocatalyst itself. The current research revealed that the decolorization
reaction is a pseudo first-order reaction when the concentration of MO is below 20 mg L−1 and the decolorization reaction is zero-order reaction when the concentration of MO is above 100 mg L−1, but the Langmuir-Hinshewood kinetic model does not describe this. The influence of IO4−, BrO3− and H2O2 were investigated in detailed. Several observations indicate that the mechanism is not involved in hydroxyl radical attacks
in MO degradation with K2S2O8 by UV irradiation. The possible underlying mechanisms are direct oxidation of the MO by S2O82− and hydrogen attraction by SO4•−.
相似文献
7.
蚕蛹甲壳素的脱色方法与机理探讨 总被引:10,自引:0,他引:10
研究了从粗甲壳素 (分离蚕蛹蛋白质后的残渣 )中提取蚕蛹甲壳素的工艺条件 ,探索了H2 O2 氧化脱色方法。实验结果表明 ,在 70℃的水浴中 ,按照m(蚕蛹渣 )∶m(5 %氢氧化钠 ) =30∶80的质量比处理 2h ,可脱净残余蛋白 ,得到黑褐色的粗蚕蛹甲壳素。用H2 O2 脱色漂白 ,工艺条件为 :6 5~ 70℃ ,pH值为 8 5± 0 5 ,时间 5h ,m (蚕蛹渣 )∶m(30 %H2 O2 ) =5 0∶130。所得甲壳素白度为 30 % ,收率为 2 5 %。双氧水脱除蚕蛹甲壳素颜色的机理可能是H2 O2 分解的O2 -2 作用于铁硫蛋白与细胞色素复合物体系中的硫 ,将体系中半胱氨酸硫氧化成亚砜 ,使得色蛋白与甲壳素相连的键断开 ,从而使色素从甲壳素上分离下来。 相似文献
8.
Enhanced production of laccases from Streptomyces psammoticus in solid-state fermentation was carried out using two different strategies: laccase inducers and scale-up process. Laccase
yield was enhanced by a wide range of aromatic inducers. The best inducer was pyrogallol, which yielded 116 U/g as compared
to the control (55.4 U/g). Scale-up studies in packed bed bioreactor was performed at different aeration rates. Aeration at
1.5 vvm was identified as the optimum condition for laccase production (75.4 U/g) in the column bioreactor. The enzyme yield
was enhanced further by combining the best conditions from the first two experiments. Fermentation was carried out in bioreactors
in the presence of 1 mM pyrogallol, which resulted in 3.9-fold increase in laccase yield (215.6 U/g). The role of laccase
in azo dye decolorization was evaluated in the presence of four different laccase mediators, at different concentrations.
1-Hydroxybenzotriazole (HOBT) proved to be the best mediator for S. psammoticus laccase and decolorized the azo dyes efficiently. Acid orange, Methyl orange, and Bismarck brown were decolorized at the
rates of 86%, 71%, and 75% respectively, by HOBT. 相似文献
9.
10.
Synthetic dyes are released into the environment from textile industrial effluents. The discharge of this colored wastewater
into rivers and lakes leads to a reduction in sunlight penetration in natural water bodies, which, in turn, decreases both
photosynthetic activity and dissolved oxygen concentration and is toxic to living beings. Bacterial isolates are optimized
for growth and biomass production before using them for decolorizing dye effluent. The bacterial isolates Bacillus sp. 1 and Bacillus sp. 2 were employed at different percentages by volume with standard nutrient concentration. Of these bacterial isolates
Bacillus sp. 2 recorded maximum color reduction. The pH and electrical conductivity (EC) were reduced in the decolorized effluent,
and a reduction in biologic oxygen demand, chemical oxygen demand, total suspended solids, and total dissolved solids (TDS)
were also observed. 相似文献