氧化石墨烯的合成及其对龙胆紫染料废水的净化研究

水体有机污染难以处理,制备吸附性能好、价廉易得、绿色高效的净化剂十分必要。采用改进的Hummers法制备GO,并研究了GO对染料污水的吸附性能。对比了该吸附剂对6种染料的吸附性能,得出对龙胆紫的吸附效果最好,故选取龙胆紫为研究对象。设计了单因素实验,系统研究了不同条件下氧化石墨烯对龙胆紫的吸附,并拟合吸附动力学和等温模型。探究发现,氧化石墨烯投加量0.03 g, pH=9,吸附时间30 min,转速1 200 r/min,染料质量浓度为50 mg/L时吸附最优,吸附率为98.36%,吸附量81.96 mg/g。等温模型符合Langmuir吸附,动力学模型符合准二级动力学吸附。实验结果显示了氧化石墨烯对龙胆紫染料具有较强的吸附能力,有望在水体染料污染处理上发挥巨大作用。     

阳离子染料废水脱色研究

在阳离子染料废水中加入废铁屑及30％H_2O_2,搅拌15分钟,废水脱色率达99％以上。     

磁性氧化石墨烯对氨基黑染料的吸附研究

采用化学共沉淀法制备CoFe2 O4@GO磁性复合材料,并对制备的CoFe2 O4@GO进行了X射线衍射(XRD)、红外光谱(FT-IR)以及热分析等表征,研究选择染料氨基黑10B为研究对象,对影响CoFe2O4@GO吸附氨基黑10B染料的参数,如溶液pH值、吸附剂用量、吸附时间、吸附容量以及样品体积等进行研究,并对洗...     

新型氧化-混凝剂处理染料废水研究

根据染料废水的特点，研究了自制产品新型氧化0混凝土剂处理染料废水的情况，探讨了药剂用量、pH值等因素对COD、色度去除率的影响。试验表明，当pH大于10，“染清”氧化－混凝剂的质量分数为0.03%，絮凝时间6min，静置沉淀35min时，该药剂对染料废水具有良好的处理效果，COD和色度的去除率最高分别可达97％和86％，从而证明该方法对于染料废水的处理是可行的。该处理工艺设备简单，系统运行稳定，操作方便，成本低。     

磁性氧化石墨烯/TiO_2复合材料的制备及光催化降解染料废水的研究

为了提高TiO2的光催化性能,采用Hummers法自制氧化石墨、纳米TiO2、FeCl3等为原料制备了磁性氧化石墨烯/TiO2(磁性GO/TiO2)复合光催化材料。以活性艳红X-3B为模拟废水,对该催化剂在紫外光下的催化活性进行了评价。结果表明,TiO2/GO材料中GO含量为3%时光催化活性最好,磁性GO/TiO2复合材料GO含量为8%时在1.4 h时可以达到93%的降解率。     

阳离子交换纤维对阳离子染料的脱色

用自制的阳离子交换纤维对阳离子染料溶液进行了静态、动态的吸附、脱色试验以及纤维吸附染料后的解吸、再生试验。结果表明:阳离子交换纤维只要制作得法,其吸附、脱色性能远优于一般活性碳,并且用0.5N 的盐酸溶液即可使纤维再生,再生方法简便且再生率较高,可达80%以上。     

絮凝和化学氧化法处理染料及印染废水研究的近况

主要介绍了一些染料及印染废水处理所最常用的絮凝和化学氧化法技术的国内外研究近况。     

氧化石墨烯膜对染料和盐的去除特性

氧化石墨烯(GO)膜能通过吸附去除染料和盐,但其通量往往较低.本研究通过过滤制备多壁碳纳米管夹层,再在其上过滤制备GO层,形成三层的MCG膜,夹层的存在极大提高膜的渗水性和通量.随着GO用量的增加,MCG的截留率增大,但通量降低.最优的GO用量推荐为217mg/m2,该膜通量约为180L/(m2·h),对亚甲基蓝的截留...     

磁性氧化石墨烯纳米粒子的制备及其对大红染料的去除

合成氧化石墨烯磁性纳米复合材料Fe_3O_4-NH_2@GO,通过透射电镜(TEM)、傅里叶变换红外光谱(FTIR)对材料的形貌、结构进行表征,并考察影响该磁性材料对水样中大红染料吸附过程的主要参数,包括吸附剂用量,pH,吸附时间及温度。结果表明,吸附剂Fe_3O_4-NH_2@GO对大红染料有较好的吸附性能,最佳吸附pH为4,吸附平衡时间为8 h,理论最大吸附量69.44 mg/g,升高温度,可提高Fe_3O_4-NH_2@GO对大红染料的吸附能力。动力学研究结果证明,该吸附过程符合准二级动力学模型,吸附等温线满足Langmuir模型。     

Characterization of graphene oxide supported porous silica for effectively enhancing adsorption of dyes

ABSTRACT

This paper reported the synthesis of graphene oxide (GO)/mesoporous SBA-15 nanocomposite with excellent adsorption properties. The samples were characterized by XRD, FESEM, TEM, FTIR, Raman spectrometer, and surface area analyzer. The adsorption study implied that incorporating GO into SBA-15 frameworks displayed much higher adsorption capacity levels than did pure SBA-15. The composite displayed uniform pore size (6.50 nm), large pore volume (1.035 cm³/g), and high surface area (891 m²/g). The adsorption capacity of samples decreased with increasing sample dosage and adsorption temperature, and increasing initial concentration of dye. The maximum adsorption capacity of the composite for methylene blue was found to be 242 mg/g. The removal efficiency reached 100%. The proposed method was simple and suitable for mass production.     

Correlation between eletrokinetic mobility and ionic dyes adsorption of Moroccan stevensite

This study aims at establishing a correlation between the electrical charge of Moroccan stevensite particles and ionic dyes adsorption. The electrophoretic mobility, (U_e), of the stevensite particles in water, was measured at pH 2.5–12 by microelectrophoresis. At pH between 2.5 and 8, U_e remained constant (U_e = ? 1.6 10^? 8 m²/(V s)), as resulting from the permanent charge of the clay mineral planar surfaces. At pH > 8, the magnitude of electrophoretic mobility increased (U_e = ? 2.7 10^? 8 m²/(V s)) due to the deprotonation of silanol groups on the surfaces. The anionic Orange G adsorption at the clay mineral–water interface was negligible whereas the methylene blue cations were strongly adsorbed due to the electrostatic attraction.     

Influences of graphene oxide support on the electrochemical performances of graphene oxide-MnO2 nanocomposites

MnO₂ supported on graphene oxide (GO) made from different graphite materials has been synthesized and further investigated as electrode materials for supercapacitors. The structure and morphology of MnO₂-GO nanocomposites are characterized by X-ray diffraction, X-ray photoemission spectroscopy, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and Nitrogen adsorption-desorption. As demonstrated, the GO fabricated from commercial expanded graphite (denoted as GO(1)) possesses more functional groups and larger interplane gap compared to the GO from commercial graphite powder (denoted as GO(2)). The surface area and functionalities of GO have significant effects on the morphology and electrochemical activity of MnO₂, which lead to the fact that the loading amount of MnO₂ on GO(1) is much higher than that on GO(2). Elemental analysis performed via inductively coupled plasma optical emission spectroscopy confirmed higher amounts of MnO₂ loading on GO(1). As the electrode of supercapacitor, MnO₂-GO(1) nanocomposites show larger capacitance (307.7 F g^-1) and better electrochemical activity than MnO₂-GO(2) possibly due to the high loading, good uniformity, and homogeneous distribution of MnO₂ on GO(1) support.     

Effects of humic acid on copper adsorption onto few-layer reduced graphene oxide and few-layer graphene oxide

The effects of humic acid (HA) on copper (Cu(II)) adsorption onto few-layer reduced graphene oxide (FRGO) and few-layer graphene oxide (FGO) were investigated using a batch equilibration method, micro-Fourier transform infrared spectroscopy, and extended X-ray absorption fine structure spectroscopy (EXAFS). The results showed that HA was adsorbed on FRGO through π–π interaction. The adsorbed HA introduced O-containing functional groups and negative charges to FRGO surfaces, increasing Cu(II) adsorption through chemical complexation and electrostatic attraction. In contrast, HA was adsorbed onto FGO mainly through polar interactions, due to its rich O-containing functional groups. The adsorbed HA had little effect on Cu(II) adsorption onto FGO because the shielding effect of HA on Cu(II) adsorption was offset by newly introduced adsorption sites of HA on FGO. EXAFS results suggested that Cu(II) was adsorbed on FRGO and FGO mainly through the coordination with their O-containing functional groups. When HA was added at pH 4.0 and 6.0, more Cu(II) was adsorbed on HA-coated FRGO. At pH 8.0, a portion of Cu(II) in solution precipitated on FRGO surface, while the presence of HA led to the formation of FRGO-HA-Cu ternary surface complexes instead of Cu(II) precipitation.     

不同还原程度氧化石墨烯-水性聚氨酯共混膜的性能研究

采用超声得到氧化石墨烯分散液,利用柠檬酸钠、抗坏血酸、L-半胱氨酸及硼氢化钠4种还原剂对氧化石墨烯进行还原,并与水性聚氨酯共混改性,通过实验探究还原后氧化石墨烯/水性聚氨酯复合材料的力学性能、介电性能。结果表明,还原后共混膜的力学性能、介电性等较未还原共混膜都有不同程度的改善,对导电性影响尤为显著,最好的共混膜提高了近1 150倍,充分体现了石墨烯良好的导电性。     

Correlation between the adsorption ability and reduction degree of graphene oxide and tuning of adsorption of phenolic compounds

Graphene oxide (GO) was prepared with a modified Hummers method and then reduced to different reduction degrees by using hydrazinehydrate. The obtained GO and reduced GO (RGO) were characterized. It was found that the reduction removed most of the oxygen-containing functional groups on the surface of GO. By using naphthalene as a probe, the interaction between RGO and organic molecules was evaluated with NMR. It was confirmed that the reduction of GO increased significantly the interaction between the π system of graphene and the π unit of organic molecules. The thermodynamic analysis indicated that the adsorption was a spontaneous, exothermic and entropy-decreasing process. It was observed that the adsorption capacities were generally increased with increasing the reduction degree of GO. The chemical structures of phenolics also affected their adsorption on RGO. The adsorption of the phenolics on RGO was enhanced by introducing electron-donating and withdrawing functional groups on the benzene ring. Depending on the chemical structures of phenolics, the surface reduction of GO to RGO-1 significantly increased the adsorption capacity for phenolics by a factor as large as 235%. A possible adsorption mechanism and correlation between the adsorption ability, reduction degree of GO and chemical structures of phenolics was discussed.     

聚丙烯/氧化石墨烯复合材料的制备，结构及性能

以石墨、浓硫酸、高锰酸钾和双氧水等为原料,通过Hummers法制备了氧化石墨烯(GO)分散液,对其冷冻干燥得到GO粉体,将GO粉体与熔融聚丙烯(PP)树脂共混制备PP/GO复合材料,采用FTIR、AFM、TEM、XRD、DSC及导热仪和氧指数测定仪等对GO及PP/GO复合材料的结构和性能进行了表征。结果表明,GO能够以双片层形式均匀地分散在PP基体中,GO/PP复合材料具有致密均匀的微观结构,其力学性能、耐热、阻燃和热传导等性能比对照样品(单纯PP树脂)有显著提高。当GO掺量为0.4%(以PP的质量为基准,下同)时,PP/GO复合材料的拉伸强度、弯曲强度和冲击强度比对照样品分别提高了29.6%、33.6%和62.7%,熔点从154.5℃提高为174.2℃,热导率提升了205.3%,极限氧指数从18.0提高到27.6。     

多孔胺基化氧化石墨烯基材料对CO2的吸附性能研究

以乙二胺(EDA)、二乙烯三胺(DETA)、四乙烯五胺(TEPA)、聚乙烯亚胺(PEI)等多胺基化合物为表面改性剂,氧化石墨烯(GO)材料为载体,采用嫁接法辅以超声处理制备了表面胺基功能化多孔吸附材料,用于CO₂气体的吸附捕集。所制备的多孔吸附材料孔径约为1.35~4.34 nm,比表面积约为98.032~210.465 m²/g。制备的四种吸附材料中,以PEI功能化吸附材料对CO₂的吸附容量最大,70℃下达到了1.5 mmol/g,且经过20次循环吸附/脱附实验后,其CO₂吸附量基本不变。吸附过程的吸附等温线线型为Ⅰ型优惠型,另外吸附实验数据与Avrami模型模拟结果符合性较好。     

氧化石墨烯/二氧化硅复合材料的制备及吸附性能

以改进的Hummers法制备的氧化石墨烯溶液为原料,十六烷三甲基溴化铵为模板剂,正硅酸乙酯为硅源,采用软模板法制备了氧化石墨烯/二氧化硅复合材料。借助红外光谱仪、扫描电子显微镜、X射线衍射仪对样品的物质结构和微观形貌进行分析表征。以亚甲基蓝模拟染料废水,石墨烯/二氧化硅复合材料为吸附剂,研究其在不同吸附时间、反应温度、ρ(亚甲基蓝)、吸附剂投加量、体系pH值下,对体系吸附量和去除率的影响。结果表明,复合材料出现了C—O—Si的特征峰,说明石墨烯与二氧化硅复合成功;且复合材料在温度为35℃,搅拌时间为90 min,pH=4,ρ(亚甲基蓝)=5 mg/L,投加量为50 mg时吸附性能最好,吸附量为22.75 mg/g,去除率为91%。