Photocatalytic degradation of an azo dye using N-doped NaTaO3 synthesized by one-step hydrothermal process

N-doped NaTaO₃ compounds (NaTaO_3−xN_x) with nano-cubic morphology were successfully synthesized by one-step hydrothermal method and Methyl Orange (MO) was used as a model dye to evaluate their photocatalytic efficiency under visible-light irradiation. The as-prepared NaTaO_3−xN_x samples were characterized by various techniques, such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and UV-vis diffuse reflectance spectra and GC-MS. The results indicate that NaTaO_3−xN_x displays a pure perovskite structure when the synthesis temperature is higher than 180 °C. Moreover, as observed by SEM images, the particles of resultant NaTaO_3−xN_x show cubic morphology with the edge length of 200-500 nm, which can be easily removed by filtration after photocatalytic reaction. Doping of N increases the photocatalytic activity of NaTaO₃, and NaTaO_2.953N_0.047 shows the highest visible-light photocatalytic activity for the degradation of MO. Based on the experiment results, a possible mechanism of the photocatalysis over NaTaO_3−xN_x and the photodegradation pathway of MO were proposed.     

TiO_2-SO_4~(2-)/Glass光催化降解甲基橙溶液的方法

研究以平玻璃和毛玻璃为载体,用Sol gel法制备附载型TiO2/Glass光催化剂,并用H2SO4溶液浸泡制得TiO2 SO2-4/Glass光催化剂。考察了光催化剂对甲基橙溶液的光催化性能。结果表明:平玻璃附载TiO2的光催化活性低于毛玻璃附载TiO2的光催化活性。且毛玻璃附载TiO2经连续6次使用后光催化活性基本不变。毛玻璃附载TiO2经H2SO4溶液处理后光催化活性明显升高。     

PSF多相UV-Fenton体系原儿茶酸与龙胆酸的增效对比

对比研究了原儿茶酸和龙胆酸对聚合硅酸铁(PSF)多相UV-Fenton体系降解橙Ⅱ的增效能力,分析了两种增效体系中铁离子转化、H2O2分解以及·OH生成之间的关系,探讨了两种增效试剂对PSF多相UV-Fenton体系的增效机制.结果表明:原儿茶酸和龙胆酸均能够有效促进催化剂Fe2+生成与释放,进而提高体系·OH的浓度、...     

超声波促进Fenton法脱色甲基橙溶液的研究

分别研究了超声波、Fenton试剂、超声波-Fenton试剂作用下甲基橙溶液的脱色和COD去除行为.结果表明,超声波单独作用甲基橙溶液几乎没有脱色效果;Fenton试剂单独作用400mg/L的甲基橙溶液30min,甲基橙色度去除率67.51%,COD去除率63.15%;而超声波-Fenton试剂时,溶液色度去除率86.91%,COD去除率80.32%.超声波与Fenton试剂对甲基橙溶液的脱色和COD去除有协同作用.Fenton试剂脱色强酸性甲基橙溶液是氧化反应,而在pH大于5时,是还原反应.     

负载型纳米Fe与负载型纳米Fe-Ni降解甲基橙的对比研究

以阳离子交换树脂为载体,合成了负载型纳米Fe和负载型纳米Fe-Ni双金属材料,并采用扫描电子显微镜和能谱分析对该材料进行表征,考察了m(FeSO4):m(树脂)、负载纳米材料加入量、溶液pH等因素对甲基橙降解率的影响.结果表明,两种负载纳米材料对0.05 g·L-1甲基橙均有较好的降解效果,甲基橙的降解率随负载纳米材料加入量的增加而增加;纳米双金属材料中Ni含量的增加有利于甲基橙的降解.在pH =4酸性条件下降解效果最佳.在优化的降解反应条件下,对比研究了负载型纳米Fe和负载型纳米Fe-Ni对甲基橙的降解效果.结果表明,负载型纳米Fe-Ni对甲基橙的降解效果要优于负载型纳米Fe.制备的材料在多次使用后经活化,仍有良好的催化稳定性.     

壳聚糖季铵盐磁性颗粒的制备及其对甲基橙的吸附效果

首先在甘氨酸盐酸盐离子液体([Gly]Cl)水溶液中制备了不同取代度的壳聚糖季铵盐,采用共沉淀法制备了纳米Fe3O4.进而以Fe3O4为核,戊二醛作交联剂,通过反相悬浮法制备交联壳聚糖季铵盐磁性颗粒,考察了反应条件对吸附效果的影响.并采用静态吸附法研究了磁性颗粒对甲基橙(MO)的吸附效果.结果表明,在25℃,pH=3的条件下,甲基橙初始浓度从20 mg.L-1增加到150 mg.L-1时,平衡吸附量从37.45 mg.g-1增加到277.5 mg.g-1.运用相关数学模型拟合实验数据得出,该吸附符合Freundlich模型,吸附动力学符合拟二级动力学模型.经4次重复使用后磁性颗粒对甲基橙的吸附率仍高于90%.     

Novel Al-doped carbon nanotubes with adsorption and coagulation promotion for organic pollutant removal

Al-doped carbon nanotubes (Al-doped CNTs) were prepared as a multifunctional integrated material of adsorbent and coagulant aid for organic pollutant removal from aqueous solution. It was observed that aluminum species were dispersed homogeneously on the surface of CNTs, and mainly anchored onto defect structures of the CNTs. The introduction of aluminium efficiently improved adsorption ability for methyl orange (MO) onto the CNTs, and maximum adsorption capacity calculated from the Langmuir isotherm model can reach 69.7 mg/g. The MO adsorption kinetics can be better described by the pseudo-second-order and pore diffusion kinetic models, and the diffusion of MO anions into pores of the Al-doped CNT adsorbent should be the rate-determining step. Thermodynamic analyses indicated that the adsorption of MO onto Al-CNTs-2.0 was endothermic and spontaneous. Moreover, adsorption capacity for MO on the Al-doped CNTs was evidently dependent on the CNT dose, solution pH and adsorbent dose. From the perspective of low-cost and multifunctional, suspension obtained during the Al-doped CNT adsorbent preparation, was tested as coagulant to remove humic acid (HA). A significant observation is that the suspension exhibited an excellent coagulation performance for HA, because abundant aluminous polymer and Al-doped CNTs existed in the suspension.     

黄麻纤维活性炭对亚甲基蓝和甲基橙吸附动力学

以黄麻纤维为原料,采用磷酸活化法制备活性炭。研究黄麻纤维活性炭对亚甲基蓝和甲基橙2种染料的吸附行为。结果表明,采用磷酸制备的活性炭,由于表面含有羧基和含磷官能团等酸性基团,能够促进活性炭对亚甲基蓝的吸附;黄麻纤维活性炭对2种染料的平衡吸附量、初始吸附速率均随着初始浓度的增加而升高;相同条件下,黄麻纤维活性炭对亚甲基蓝的平衡吸附量大于甲基橙;黄麻纤维活性炭对两种染料的吸附行为更符合准二级动力学模型。     

橘子皮皂化交联改性及其对重金属离子的吸附

以生物废料橘子皮(OP)为原料,经乙醇、NaOH和CaCl2处理,得到皂化交联改性橘子皮(SCOP)生物吸附剂,将其用于对重金属离子Cu2+、pb2+、Cd2+、Zn2+和Ni2+的吸附,并研究了溶液pH、吸附时间和重金属离子初始浓度对SCOP吸附性能的影响.结果表明,重金属离子在改性橘子皮上的吸附速率快,符合准二级动力学方程;改性橘子皮对Cu2+、pb2+、Zn2+和Ni2+的吸附等温线符合Langmuir方程,对Cd2+的吸附等温线符合Freundlich方程,根据Langmuir方程计算对Cu2+、pb2+、Cd2+、Zn2+和Ni2+的饱和吸附量分别为72.73、209.80、85.84、56.18、33.80mg/g,均高于改性前.改性后的橘子皮生物吸附剂可以再生重复使用4次以上,是性能良好的重金属离子吸附剂.     

丙酮/氯离子协同活化过一硫酸盐降解酸性橙

采用丙酮/氯离子（Cl^-）协同活化过一硫酸盐（PMS）降解偶氮染料酸性橙7（AO7）.研究发现,与Cl^-/PMS体系相比,丙酮/Cl^-/PMS体系降解AO7的效果显著增强,相应的AO7表观速率常数从0.0767增加到0.1725min^-1.考察了丙酮/Cl^-/PMS体系降解AO7的主要影响因素（初始pH值、Cl^-浓度、PMS浓度、丙酮浓度）.结果表明,在碱性环境下,随着Cl^-、PMS和丙酮浓度的增加,AO7的降解效果有所增强;研究丙酮/Cl^-/PMS体系降解AO7的降解机制.自由基猝灭实验表明,丙酮/Cl^-/PMS体系中没有自由基（硫酸根自由基（SO₄^－·）和羟基自由基（HO·））的产生,而次氯酸根（ClO^-）浓度在反应过程中逐渐增加,得出丙酮作为催化剂促进Cl^-和PMS产生更多HClO的结论.通过紫外可见光谱分析,表明AO7分子中偶氮键及萘环结构均被破坏.