Fe-MnOx催化臭氧氧化甲基橙的研究

实验以甲基橙为目标物,考察Fe-MnOx的催化效果,同时比较不同煅烧温度（300°C、400°C、500°C、600°C和700°C）、Fe/Mn混合比例（Fe/Mn=1/3、Fe/Mn=1/1和Fe/Mn=1/3）等制备条件对催化剂活性的影响,力求得到催化剂的最佳制备条件。结果表明：在400°C,Fe/Mn=1:1的制备条件下,Fe-MnOx催化剂对催化臭氧降解甲基橙表现出显著的催化活性,反应进行20min,甲基橙的去除率高达70.26%,较单独臭氧氧化提高了32.29%;加入叔丁醇后,明显抑制甲基橙去除率,说明催化过程不仅存在羟基自由基反应机理,而且存在臭氧分子与吸附在催化剂表面的甲基橙直接反应的反应途径;为了进一步了解催化剂的催化活性和内部结构之间的内在关系,采用XPS、XRD、TEM和BET等检测技术对催化活性最好的Fe-MnOx催化剂进行表征。表征的结果显示：催化剂中存在Fe2O3、FeO(OH)、 MnO2和Mn5O8,且催化剂结构呈不定晶型,结构疏散,表面孔隙多,比表面积高达117.81 m2/g。     

多糖巨球对甲基橙的吸附研究

以马铃薯淀粉为原料,采用反相悬浮法制备了多糖巨球,利用可见光光谱仪研究了多糖巨球对甲基橙的吸附特性。结果表明,甲基橙初始质量浓度、pH值和温度对多糖巨球的吸附量影响明显。当多糖巨球投入量为1 g、pH为6.848、温度为20℃时,吸附率达99.4%。利用Langmuir和Freundlich等温吸附模型对多糖巨球等温吸附曲线进行了描述,实验结果符合Freundlich模型(R2=0.999)。     

多糖巨球对甲基橙的吸附研究

以马铃薯淀粉为原料,采用反相悬浮法制备了多糖巨球,利用可见光光谱仪研究了多糖巨球对甲基橙的吸附特性。结果表明,甲基橙初始质量浓度、pH值和温度对多糖巨球的吸附量影响明显。当多糖巨球投入量为1g、pH为6．848、温度为20℃时,吸附率达99．4％。利用Langmuir和Freundlich等温吸附模型对多糖巨球等温吸附曲线进行了描述,实验结果符合Freundlich模型（R^2=0．999）。     

纳米TiO_2的制备及其光催化降解甲基橙

以TiCl_4、氨水及双氧水为主要原料,通过水解法制备出纳米TiO_2光催化剂。采用SEM分析手段对制备的TiO_2颗粒进行了表征。以甲基橙溶液模拟染料废水,TiO_2为催化剂,在紫外光照条件下考察了TiO_2投加量、甲基橙初始浓度、光照时间、溶液pH值及重复利用次数对甲基橙光催化降解效率的影响。实验结果表明:TiO_2最佳的投加质量浓度为0.20 g/L;光催化反应4 h后,甲基橙的降解率可达95.67%;酸性条件有助于甲基橙的去除;TiO_2光催化剂在重复使用5次之后仍能保持较高的催化活性,甲基橙的降解率为90.35%。     

磁性壳聚糖微球的制备及其性能

用共沉淀法制备纳米级Fe3O4磁流体,并对其用油酸进行表面改性.采用化学交联法,在分散有磁流体的壳聚糖溶液中,加入适量的戊二醛交联剂,制得内核为磁性Fe304,外层包有壳聚糖的纳米级的磁性壳聚糖复合微球.考察了壳聚糖质量浓度、NaOH滴加量及搅拌速度等因素对磁性壳聚糖微球粒径、粒径分布以及形貌等对复合过程的影响,确定了...     

磁性壳聚糖微球的制备及其性能

用共沉淀法制备纳米级Fe3O4磁流体,并对其用油酸进行表面改性。采用化学交联法,在分散有磁流体的壳聚糖溶液中,加入适量的戊二醛交联剂,制得内核为磁性Fe3O4,外层包有壳聚糖的纳米级的磁性壳聚糖复合微球。考察了壳聚糖质量浓度、NaOH滴加量及搅拌速度等因素对磁性壳聚糖微球粒径、粒径分布以及形貌等对复合过程的影响,确定了制备磁性壳聚糖微球的最佳条件,并用电镜、红外光谱图、粒径分析仪等方法对磁性壳聚糖微球的形态和组成特性进行分析。最后得出平均粒径为348.5 nm,表面富含羟基、氨基和醇羟基等官能团,磁性明显、分散性良好的磁性壳聚糖微球。     

银纳米粒子/聚多巴胺微球的制备及催化性能

利用多巴胺在碱性醇/水体系中的氧化自聚反应制备得到粒径均一的聚多巴胺纳米微球(polydopamine spheres,PDS),并进一步利用PDS结构中儿茶酚胺的还原性,原位还原硝酸银负载银纳米粒子,建立了银纳米粒子/聚多巴胺微球(Ag nanoparticles loaded PDS,AgNPs/PDS)的简单制备方法。利用紫外-可见光谱、傅里叶变换红外光谱、扫描电子显微镜、X射线光电子能谱和电化学溶出伏安法对PDS及AgNPs/PDS的形貌、结构及成分进行分析。在最优条件下,粒径约为40nm的球形AgNPs均匀固载在平均粒径约为200nm的PDS表面。通过紫外-可见吸收光谱现场监测了AgNPs/PDS对硼氢化钠还原4-硝基苯酚(4-nitrophenol,4-NP)的催化作用,结果表明AgNPs/PDS极大地加速了4-NP的还原反应。这种绿色、简单、快捷的复合材料制备方法有望为新型功能材料构建提供新途径。     

微波诱导Cu基催化剂催化H_2O_2氧化降解甲基橙模拟染料废水

以-γAl2O3为载体,采用浸渍法制备了负载Cu基催化剂,将其应用于微波诱导催化氧化处理模拟甲基橙废水。XRD表征及实验结果表明,在200℃下焙烧得到的碱式硝酸铜比氧化铜具有更高的催化活性。对于25 mL质量浓度为50 mg·L-1的模拟甲基橙废水,最佳的处理工艺条件为:微波辐照功率700 W,辐照时间7 min,催化剂加入量0.3 g,H2O2加入量2 mL。在此工艺条件下,水中甲基橙的脱除率达98.7%。催化剂连续使用5次后甲基橙脱除率仍达98%以上。     

磁性高分子微球Fe3O4／PMMA的制备与表征

以油酸作为表面活性剂,采用化学共沉淀法制备了具有良好晶型、分散性好的纳米四氧化三铁。以甲基丙烯酸甲酯（MMA）作为反应单体,DVB为交联剂,使用水溶性引发剂KPS,采用单体聚合法制备磁性高分子微球Fe30dPMMA,该磁性高分子微球具有明显的核壳结构,粒子尺寸约为500nm。     

含松香的聚氨酯载药微球的制备及性能

采用预聚—扩链—中和法合成松香基聚氨酯(RPU),以其为载体,以5-氟尿嘧啶(5-Fu)为模型药物,通过悬浮聚合法制备了负载5-Fu的松香基聚氨酯微球(5-Fu/RPUMs)。采用单因素实验优化了药物负载条件,通过红外光谱、X射线光电子能谱、扫描电子显微镜、能谱分析等对载药微球进行表征,研究了载药微球的体外释放性能及药物释放动力学模型。结果表明：成功制备了5-Fu/RPUMs微球,平均粒径为35.0μm,表面光滑圆整且有孔。药物最佳负载条件为：ρ_5-Fu=120 mg/mL,致孔剂种类为正丁醇/甲苯,此条件下RPU对5-Fu的包封率达63.35%,载药量达7.60%。5-Fu/RPUMs在不同pH下表现出不同的缓释性能,具有pH敏感性;在pH=6.8的PBS缓冲溶液中,264 h后的累积释放率为65.80%,具有长效的缓释作用。     

C_OFe_2O_4催化PMS降解甲基橙的实验

采用溶胶凝胶法制备了磁性催化剂铁酸钴(C_OFe_2O_4),借助于X射线衍射(XRD)、扫描电子显微镜(SEM)、BET比表面积、磁滞回线(VSM)等手段对催化剂进行表征。以甲基橙溶液模拟染料废水,开展了C_OFe_2O_4催化活化过一硫酸氢钾(PMS)降解甲基橙的实验研究。考察了催化剂用量、PMS的浓度、溶液初始p H、反应温度对甲基橙降解效率的影响,得到了反应的最佳条件。当C_OFe_2O_4浓度为0.16 g/L,PMS浓度2.3 mmol/L,溶液初始pH为3,反应温度为25℃时,甲基橙的降解效率可达89.96%。通过查阅相关文献及X射线光电能谱分析(XPS)推测了甲基橙的降解机理。     

Magnetic Fe_3O_4@mTiO_2-AIPA Microspheres for Separation of Phosphoproteins and Non-phosphoproteins

A novel phosphoprotein separation material was developed, which is constructed by a magnetic mesoporous Fe_3 O_4@TiO_2(Fe_3 O_4@mTiO_2) microsphere and a 5-aminoisophthalic acid(AIPA) monolayer that provides additional binding sites toward phosphate groups. The results of characteristic experiments demonstrated that Fe_3 O_4@mTiO_2-AIPA had good dispersability, high magnetic susceptibility, and satisfactory grafting ratio of AIPA, ascribed to the large specific surface area of the inorganic substrate. Taking advantages of these features, Fe_3 O_4@mTiO_2-AIPA was successfully utilized to separate α-casein(a typical phosphoprotein) and bovine serum albumin(BSA, a typical non-phosphoprotein) from their mixtures(molar ratio = 1:2). Through adjusting pH and polarity of solutions, the BSA and α-casein were respectively enriched in washing fraction and elution fraction. This result displays the good potential of Fe_3 O_4@mTiO_2-AIPA for application in phosphoprotein enrichment.     

SO4^2—／Fe2O3催化合成草酸二异戊酯

以固体酸SO4^2-/Fe2O3为催化剂,草酸和异戊醇为原料,采用三因素三水平进行正交实验,筛选出合成草酸二异成酯的最佳合成条件。     

微波辐射法制备Fe_3O_4/P(MMA-AMPS)磁性微球

采用微波辐射法制备了油酸(OA)表面修饰的Fe_3O_4颗粒,透析后得到稳定的Fe_3O_4磁流体。在Fe_3O_4磁流体和十二烷基硫酸纳(SDS)的存在下,以甲基丙烯酸甲酯(MMA)和2-丙烯酰胺基-甲基丙磺酸(AMPS)为单体,采用微波辐射乳液聚合法制备了MMA-AMPS共聚物包覆Fe_3O_4磁性高分子微球,并对磁性高分子微球的形态与结构进行了表征,测定了磁性高分子微球的粒径、磁含量和饱和磁化强度。结果表明:在优化聚合反应条件下,通过微波辐射乳液聚合法可制备出粒径为0.25~0.50μm,饱和磁化强度为4.2emu·g-1的磁性高分子微球。     

Electrochemical Sensing of Heavy Metal Ions based on Monodisperse Single-crystal Fe_3O_4 Microspheres

Single-crystal Fe_3 O_4 with monodisperse microspheres structure has been used for individual electrochemical detection of heavy metal ions. Morphology and structure of the as-prepared Fe_3 O_4 microspheres were characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM) and X-ray diffraction(XRD). Meanwhile the electrochemical properties of the Fe_3 O_4 microspheres modified glass carbon electrodes(GCE) were characterized by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS), and the enhanced electrochemical response in stripping voltammetry for individual detection of Pb(Ⅱ), Hg(Ⅱ), Cu(Ⅱ), and Cd(Ⅱ) was evaluated using square wave anodic stripping voltammetry(SWASV). With high specific surface area and excellent catalytic activity toward heavy metal ions, the as-prepared monodisperse and single-crystal Fe_3 O_4 microspheres show a preferable sensing sensitivity(22.2 μA/μM) and limit of detection(0.0699 μM) toward Pb(Ⅱ). Furthermore, the electrochemical sensor of Fe_3 O_4 microspheres exhibits excellent stability and it also offers potential practical applicability for the determination of heavy metal ions in real water samples. This study provides a potential simple and low cost iron oxide for the construction of sensitive electrochemical sensors applied to monitor and control the pollution of toxic metal ions.     

Ni-L/g-C3N4复合材料光催化降解甲基橙性能的研究

为了提升g-C3N4的光催化降解性能,引入一种Ni金属配合物对g-C3N4进行改性.利用水热法合成基于1,3-二-(4′-(5′-四唑基)苯氧基)苯甲酸的Ni配合物Ni-L,将Ni-L负载到g-C3N4上,得到Ni-L/g-C3N4复合材料.对Ni-L/g-C3N4进行XRD、SEM表征,对不同负载量的复合物进行荧光性...     

Preparation of Fe_3O_4-octadecyltrichlorosilane for Removal of Methyl Orange and Methylene Blue: Influence of p H and Ionic Strength on Competitive Adsorption

Fe_3O_4-octadecyltrichlorosilane(Fe_3O_4-OTS)was synthesized and used to remove dyes in a competitive system.Fe_3O_4-OTS was prepared by slow hydrolysis of OTS in cyclohexane on the surface of Fe_3O_4obtained through coprecipitation method.Scanning electron microscope(SEM),energy dispersive spectrometer(EDS),and contact angle analyzer(CA)were used to analyze the properties of Fe_3O_4-OTS.Methyl orange(MO)and methylene blue(MB)were selected as model molecules to study the influence mechanism of p H and ionic strength on competitive adsorption.The results of EDS and CA indicated that Fe_3O_4 was modified successfully with OTS on the surface.Silicon appeared and carbon content increased obviously on the surface of adsorbent.Contact angle of adsorbent increased from 0~o to 107~o after being modified by OTS.Fe_3O_4-OTS showed good separation for MO and MB in competitive system,which has potential to separate dyes in sewage.Separation factor(β~O_B)changed from 18.724 to 0.017,when p H changed from 7 to 12,revealing that MO and MB could be separated almost thoroughly by Fe_3O_4-OTS.p H could change the surface charge of Fe_3O_4-OTS and structure of dyes,and thus change the interactions of competitive system indirectly.Even though hydrophobic interaction was enhanced,ionic strength reduced the difference of electrostatic interaction between dyes and Fe_3O_4-OTS.So it is unfavorable to separate dyes with opposite charges when ionic strength increases.These findings may provide theoretical guidances to separate two-component dye pollutants.     

Fe3O4超细粒子催化剂的制备

使用TG DTA、XRD、Mossbauer谱等方法考查了制备条件对草酸铁热分解过程的影响。结果表明 ,Fe2 (C2 O4) 3·xH2 O在氮气流中 473K下失去结晶水的同时 ,将部分转变成草酸亚铁 ,生成的草酸亚铁只有在 573K以上才开始分解 ,草酸铁则在 533K时就开始分解 ,且分解产物为超细Fe3O4粒子。     

纳米Fe_3O_4类酶催化Na_2S_2O_8氧化降解对硝基酚

采用超声辅助反向共沉淀法制备了高活性的Fe3O4磁性纳米颗粒（Fe3O4MNPs）.采用XRD,FT-IR和Raman等仪器对Fe3O4MNPs的组成、结构进行了表征和研究.以Fe3O4MNPs为类酶催化剂,Na2S2O8为氧化剂,在室温25℃的条件下,降解对硝基酚的优化条件为：10 mg.L-1对硝基酚溶液,在pH=3.8,Fe3O4MNPs用量为0.9 g.L-1,Na2S2O8用量为6.3 mmol.L-1时,无需超声、紫外光照和Gamma辐射的条件下,30 min后其降解率达到97%以上.     

TiO_2-doped Fe_3O_4 nanoparticles as high-performance Fenton-like catalyst for dye decoloration

Fenton reaction based on Fe2+-H2O2 system has been widely applied in water remediation, but the obvious drawbacks largely hinder its practical uses. Alternatively, heterogeneous nanomaterials with proper surface modification could be used as Fenton-like catalysts. Surface doping of Ti O2 could concentrate the pollutants surrounding the Fe3O4 catalyst, which might benefit the catalytic performance of Fe3O4. Herein, we reported that Ti O2-doped Fe3O4 nanoparticles(NPs) could be used as high-performance Fenton-like catalyst for dye decoloration in near neutral environment, where the doping of Ti O2 on Fe3O4 surface dramatically improved the catalytic activity of Fe3O4 in Fenton-like reaction. Ti O2-doped Fe3O4 NPs catalyzed the decomposition of H2O2 to oxidize methylene blue without external energy supply, resulting in effective decoloration. Ti O2-doped Fe3O4 NPs showed high catalytic activity under various p H values and even in the presence of radical scavenger. More catalysts and H2O2 would facilitate the decoloration. At higher temperature, the decoloration became faster and more effective. The implication to the environmental applications of Ti O2-doped Fe3O4 NPs is discussed.