氧化程度对氧化石墨烯吸附亚甲基蓝性能的影响

基于改进Hummers法,调控氧化剂KMnO₄用量制备了不同含氧官能团含量的氧化石墨烯（GOs）。采用XRD、XPS、AFM和FTIR分析了KMnO₄用量对GOs的结构特征、含氧官能团类型及含量的影响,研究了氧化程度对GOs吸附亚甲基蓝（MB）性能的影响。结果表明：KMnO₄用量对GOs-n（n=2,3,4（的含氧官能团类型和含量有显著影响;MB最大饱和吸附量依次为728.44、965.63和807.29 mg·g^-1,与Langmuir模型单分子层饱和吸附量的标准差为3.6%、3.7%和4.2%,吸附动力学过程符合准二级动力学模型,R²> 0.99。以GOs结构层上去质子化的羟基（-C-O^-）和羧基（-COO^-）为主要活性位点与MB发生化学控速的单分子层放热吸附,吸附热在20~27 kJ·mol^-1之间;低氧化程度的GOs以离子交换吸附为主导,吸附性能与GOs结构中-C-O（H（和-COO（H（的总量呈正相关。随氧化程度加深,GOs结构中环氧基（C-O-C）和羰基（C═O）以氢键作用吸附MB对吸附量的影响凸显。     

Mesoporous silica supported cobalt oxide catalysts for catalytic removal of benzene

Two types of mesoporous silica SBA-15 with different pore diameter were synthesized with an ageing temperature of 373 K and an ageing temperature of 308 K, respectively; in addition, mesoporous silica with amorphous structure was synthesized by adding organosiloxane as part of the silica source during the synthesis procedure. Mesoporous silica and conventional alumina supported cobalt oxide catalysts were prepared by incipient wetness impregnation method. These materials were characterized by FT-IR, nitrogen adsorption–desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM) and Temperature programmed reduction (TPR) techniques, and the activity of the supported cobalt oxide catalysts for deep oxidation of benzene were evaluated in a fixed-bed reactor. It seems that the pore diameter of the silica increase with the elevation of the ageing temperature. Mesoporous silica supported cobalt oxide catalysts are more active than conventional alumina supported ones. Cobalt oxide can be relatively better dispersed on the surface of mesoporous silica which has larger pore diameter and surface areas. Meanwhile, more silanol groups exist on the surface of amorphous silica, which could induce a strong interaction with the supported cobalt oxide species, leading to poor activity for benzene oxidation.     

金刚烷胺/氧化石墨烯复合材料的制备及其吸附性能

以氧化石墨烯和金刚烷为原料，通过水相合成法制备了金刚烷胺功能化氧化石墨烯复合材料A/GO，以FT-IR、XRD和XPS对A/GO进行了结构表征，并考察了A/GO对有机染料的吸附性能。结果表明，与氧化石墨烯相比，A/GO对甲基蓝（AB93）表现出高效吸附性，其吸附动力学和吸附等温模型分别符合拟二级动力学和Langmuir模型，理论最大吸附容量（qm）为1250.0 mg/g。热力学分析表明，A/GO吸附AB93是自发的放热过程。A/GO吸附AB93对盐（NaCl和KCl）表现出良好的耐盐性，而CaCl2能有效地促进A/GO吸附AB93。对于刚果红和AB93等的混合染料体系，A/GO能选择性吸附AB93。     

Graphene oxide/poly(vinyl alcohol) hydrogels with good tensile properties and reusable adsorption properties

Graphene oxide (GO)/poly(vinyl alcohol) (PVA) hydrogel (PGOH), which possesses good tensile and reusable absorption properties, has been prepared by the freezing–thawing method. The presence of GO visibly decreases the swelling ratio of PGOH and significantly enhances the tensile properties of PGOH due to the formation of hydrogen bonds between the GO and PVA. The maximum tensile strength and the equilibrium adsorption capacity of methylene blue (MB) of PGOH with 0.5?wt-% GO (PGOH-0.5) is found to be 15, being 4.1 times higher than that of pure PVA hydrogel. The spontaneous adsorption obeys the intraparticle diffusion kinetic model. In addition, PGOH-0.5 exhibits a promising cycling absorption performance. The 1st and 5th cycle of dye removal for PGOH-0.5 reached to 92 and 70%, respectively. Such enhancement in adsorption can be attributed to π–π stacking and strong electrostatic attraction between GO and MB.     

微波法制多孔石墨烯及对亚甲基蓝的吸附性能

以改进的Hummers法合成的氧化石墨烯为自组装原料,通过微波加热的方式制备三维多孔石墨烯材料.并采用场发射扫描电子显微镜、傅立叶红外光谱仪、X射线衍射仪对石墨、氧化石墨烯、三维多孔石墨的微观形貌和内部结构进行表征分析.以亚甲基蓝为吸附质、三维多孔石墨烯为吸附剂,研究其吸附性能.结果表明,三维多孔石墨烯材料的最大吸附量...     

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。     

Reduced chemically modified graphene oxide for supercapacitor electrode

An efficient active material for supercapacitor electrodes is prepared by reacting potassium hydroxide (KOH) with graphene oxide followed by chemical reduction with hydrazine. The electrochemical performance of KOH treated graphene oxide reduced for 24 h (reduced chemically modified graphene oxide, RCMGO-24) exhibits a specific capacitance of 253 F g^-1 at 0.2 A g^-1 in 2 M H₂SO₄ compared to a value of 141 F g^-1 for graphene oxide reduced for 24 h (RGO-24), and good cyclic stability up to 3,000 cycles. Interestingly, RCMGO-24 demonstrated a higher specific capacitance and excellent cycle stability due to its residual oxygen functional groups that accelerate the faradaic reactions and aid in faster wetting. This non-annealed strategy offers the potential for simple and cost-effective preparation of an active material for a supercapacitor electrode.     

乳液法制备石墨烯气凝胶及其吸附水中亚甲基蓝

利用乳液法制备多孔石墨烯气凝胶（emGA）,改变乳液油水比制备不同的emGA。扫描电子显微镜（SEM）、傅里叶红外光谱（FTIR）、氮气吸附脱附等表征显示,emGA具有多孔结构,经水热还原后含氧官能团大部分被除去,比表面积为103.3～243.1m²/g。以亚甲基蓝（MB）浓度和温度作为变量,考察emGA对水中MB的吸附效果。结果表明,emGA的比表面积越大,其对MB平衡吸附量越大;当初始浓度越大,温度越高,则吸附有利。吸附动力学数据表明emGA吸附MB符合准二级动力学模型和内扩散模型,吸附过程分为大孔扩散和微孔扩散。吸附等温线数据拟合结果符合Langmuir模型,表明emGA对MB的吸附属于单分子层吸附。Langmuir模型计算出emGA-2饱和吸附量为307.7mg/g,与实验值291.3mg/g较为接近。分析热力学参数发现,emGA吸附MB为自发吸热过程,且吸附过程属于物理吸附。     

活化氧化石墨烯的制备及对甲基橙的吸附

为了提高氧化石墨烯(GO)的比表面积和吸附性能,采用氢氧化钾对GO进行高温固相活化,制备出活化氧化石墨烯(GOKOH),并将其用于对水中阴离子染料甲基橙(MO)的吸附研究。结果表明,GOKOH的比表面积可达672.48 m2/g。GOKOH能在较宽的p H范围内实现对MO的高效去除,去除率高达94.87%,吸附平衡时间约为150 min。准一级和准二级动力学拟合的理论平衡吸附容量分别为549.87 mg/g和549.45 mg/g,Langmuir模型的饱和吸附容量为632.91 mg/g。该吸附过程受边界层扩散与颗粒内扩散两个步骤控制,符合二级动力学模型和Langmuir模型,并主要以化学吸附为主。     

地质聚合物微球的制备及对染料的吸附

以偏高岭土和改性水玻璃为原料，采用分散悬浮固化法制备偏高岭土基地质聚合物微球（GM）。使用扫描电子显微镜、比表面积及孔径分布测试仪、傅里叶变换红外光谱仪和X射线粉末衍射仪对其进行结构表征，并研究了GM对亚甲基蓝的吸附性能。结果表明：GM对亚甲基蓝的吸附基本符合准二级动力学模型和Langmuir吸附等温线模型，333 K时最大理论吸附量为100.1 mg/g。GM对亚甲基蓝的吸附是自发吸热过程。使用后的GM在5次循环利用后，GM对MB的去除率仍然可达81.56%，易于回收和再生。分析了GM对不同阴阳离子型染料的吸附效果，结果表明，GM对阳离子型染料具有选择性吸附。GM是一种低价、有效、绿色、可循环利用的吸附剂，可用于去除水中阳离子型染料污染物。     

Removal of methylene blue from coloured effluents by adsorption onto SBA‐15

Adsorption has been proven to be the most efficient method for quickly lowering the concentration of dissolved dyes in an effluent. In this regard, activated carbon is the most widely used adsorbent for removal of dyes from aqueous solution. However, the high cost of production and regeneration make it uneconomical. Therefore, inorganic adsorbents (e.g. zeolites) with high surface areas have been used as alternatives to carbon adsorbents. Microporous zeolites ZSM‐5, NH₄‐Beta, MCM‐22 and mesoporous materials MCM‐41 have been investigated for the removal of dyes from aqueous solutions and they show effective adsorption performance. SBA‐15 possesses a larger pore size and pore wall thickness than MCM‐41. As a result, SBA‐15 has greater potential for the adsorption of methylene blue with larger molecule size and higher hydrothermal stability than the M41S family. SBA‐15 is an excellent adsorbent for methylene blue (MB), exhibiting 280 mg g^?1 adsorption capacity and about 100% fading rate for MB. The adsorptive process is so fast that adsorption equilibrium is achieved in 5 min. In addition, SBA‐15 can be effectively recovered by calcination and reused 10 times without significant loss in removal of MB from aqueous solution. The efficient adsorption of MB molecules onto SBA‐15 was ascribed to MB adsorbed into the pore channels of SBA‐15, which was confirmed by nitrogen physisorption analysis of the adsorbent before and after adsorption. The long reuse life of the adsorbent suggests a high potential for application in industry. Copyright © 2010 Society of Chemical Industry     

微孔木薯淀粉吸附特性研究

对微孔木薯淀粉吸附次甲基兰的特性进行了研究，发现微孔淀粉对次甲基兰的吸附遵循Langmuir吸附等温方程式，其吸附速率方程为：A=0．4228t^0.243。淀粉颗粒表面ξ电位决定其对次甲基兰的饱和吸附量，ξ负电位增大，吸附量增加；当ξ正电位增大，则吸附量下降。     

Improved electrochemical performance of graphene oxide supported vanadomanganate (IV) nanohybrid electrode material for supercapacitors

Graphene oxide (GO)-supported polyoxometalates (POMs) have been considered as promising electrode materials for energy storage applications due to their ability to undergo fast and reversible redox reactions. Herein, vanadomanganate-GO composites (K₇Mn^IVV₁₃O₃₈.18H₂O-GO with 2:1 and 4:1 ratio) were investigated for use as potential electrode materials in supercapacitors (SCs). The K₇Mn^IVV₁₃O₃₈.18H₂O (MnV₁₃) was synthesized and anchored on GO through electron transfer interaction and electrostatic interaction to make the composite electrodes for the present study. All synthesized electrode materials were fully characterized by various techniques, e.g., Fourier Transform Infrared (FTIR) Spectroscopy, Powder X-ray Diffraction (XRD), Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy (SEM/EDS) and High Resolution-Transmission Electron Microscopy (HR-TEM). The electrochemical properties of MnV₁₃/GO composites with different MnV₁₃/GO ratios were investigated by two-electrode cyclic voltammetry (CV) and galvanostatic charge/discharge (GCD) in different electrolytes. The MnV₁₃/GO composite of ratio 2:1 in 1 M LiCl electrolyte and that of ratio 4:1 in 1 M Na₂SO₄ electrolyte showed significant specific capacitance values of 269.15 F/g and 387.02 F/g, respectively and energy density of 37.38 Wh/kg and 53.75 Wh/kg, respectively for a scan rate of 5 mV/s. Interestingly, the 1:1 (MnV₁₃/GO) composite in 1 M Na₂SO₄ and 1 M LiCl electrolytes showed very low specific capacitance values as the deposition of MnV₁₃ on GO was not sufficient, as indicated by FTIR and SEM. Thus, it is evident that the specific capacitance value of these composite materials depends on the amount of MnV₁₃ deposited on GO and these composite materials exhibit the potential to improve the performance of GO-based SCs.     

Production and characterization of a novel hierarchical porous silica adsorbent for removal of methylene blue dye from wastewaters

Adsorption of methylene blue (MB) dye by hierarchical porous silica (HPS) is reported as a means of removing the dye from wastewater. HPS was produced through a sol–gel process by templating on rubber particles in skimmed natural rubber latex. The silica precursor was tetraethyl orthosilicate and the costructure directing agent was 3-aminopropyltriethoxysilane. Based on nitrogen-sorption, the HPS had a total pore volume of 1.0?cm³/g, a specific surface area of 237?m²/g, and a peak pore size of 4?nm. Larger pores (sizes >100?nm to 1?µm) were observed by scanning electron microscopy. The pores had an ink-bottle morphology of narrow necks connected to large cavities. The adsorption obeyed the Langmuir isotherm and was endothermic. Pseudo-second-order adsorption kinetics were observed. The specific adsorption of MB on HPS was 0.225?mmol/g at equilibrium. HPS was superior to many adsorbents reported for removing MB from aqueous media.     

氧缺陷位MoO3- x 的制备及其吸附性能研究

纺织印染废水中的有机污染物如亚甲基蓝的高效吸附净化是环境领域的重要研究课题,三氧化钼独特的片层结构极具吸附应用潜力。通过微波一步法制备了不同氧空穴浓度的氧化钼,具有不同的表面电荷分布,利用氧空穴氧化钼表面所带负电荷选择性高效吸附阳离子偶氮染料亚甲基蓝。揭示了氧空穴浓度与吸附性能之间的关系,发现氧空穴浓度越高则氧化钼吸附速率越快;吸附过程符合Langmuir等温线模型和准二级动力学模型,表明该吸附过程属于单分子层吸附,并分析了其吸附机理。氧空穴氧化钼(MoO_{3- x} )为金属氧化物在染料吸附领域的发展和应用提供一定的基础数据和理论基础。     

Insight into the dynamic adsorption behavior of graphene oxide multichannel architecture toward contaminants

Graphene oxide (GO) channels exhibit unique mass transport behaviors due to their flexibility, controllable thinness and extraordinary physicochemical properties, enabling them to be widely used for adsorption and membrane separation. Nevertheless, the adsorption behavior of nanosized contaminants within the channels of GO membrane has not been fully discussed. In this study, we fabricated a GO membrane (PGn, where n represents the deposition cycles of GO) with multi channels via the cross-linking of GO and multibranched poly(ethyleneimine) (PEI). Phenol was used as molecularprobe to determine the correlations between dynamic adsorption behavior and structural parameters of the multilevel GO/PEI membrane. PG8 shows higher adsorption capacities and affinity, which is predominantly attributed to the multichannel structure providing a large specific surface for phenol adsorption, enhancing the accessibility of active sites for phenol molecules and the transport of phenol. Density functional theory calculations demonstrate that the adsorption mechanism of phenol within GO channel is energetically oriented by hydrogen bonds, which is dominated by oxygen-containing groups compared to amino groups. Particularly, the interfaces which facilitate strong π-π interaction and hydrogen bonds maybe the most active regions. Moreover, the as-prepared PG8 membrane showed outstanding performance for other contaminants such as methyl orange and Cr(VI). It is anticipated that this study will have implications for design of GO-related environmental materials with enhanced efficiency.     

Electrochemical sensing based on graphene oxide/Prussian blue hybrid film modified electrode

A novel graphene oxide (GO)/Prussian blue (PB) hybrid film was constructed by electropolymerizing Prussian blue onto the GO modified glassy carbon electrode, and its electrochemical behaviors were studied. Raman spectra were used to investigate the successful formation of the GO/PB hybrid film. Electrochemical experiments showed that the graphene oxide greatly enhanced electrochemical reactivity of the PB. Moreover, a much higher Prussian blue (PB) loading (6.388 × 10⁻⁸ mol cm⁻²) is obtained as compared to the bare glass carbon surface (3.204 × 10⁻⁹ mol cm⁻²). The GO/PB hybrid film modified electrode was used for the sensitive detection of hydrogen peroxide. The sensor exhibited a wide linearity range from 5.0 × 10⁻⁶ to 1.2 × 10⁻³ M with a detection limit of 1.22 × 10⁻⁷ M (S/N = 3), high sensitivity of 408.7 μA mM⁻¹ cm⁻² and good reproducibility. Furthermore, with glucose oxidase (GOD) as a model, the GO/PB/GOD/chitosan composite-modified electrode was also constructed.The resulting biosensor exhibited good amperometric response to glucose with linear range from 0.1 to 13.5 mM at 0.1 V, good reproducibility and detection limit of 3.43 × 10⁻⁷ M (S/N = 3). In addition, the biosensor presented high selectivity and long-term stability. Therefore, the PB/GO hybrid films-based modified electrode may hold great promise for electrochemical sensing and biosensing applications.     

醚化改性麦糟吸附材料的制备及其对亚甲基蓝的吸附

以麦糟(RSG)为基材,氯乙酸为醚化剂,NaOH为催化剂,制备了醚化改性麦糟(MSG),研究了MSG对亚甲基蓝(MB)的吸附性能.考察了改性条件对MB吸附效果的影响.结果表明,在固液比1:50(g:mL)、n(NaOH):n(ClCH2COOH)=1.25:1.0、醚化温度为75℃、醚化时间为2.5 h的条件下,制得的...     

介孔硅SBA-15对水溶液中咪唑基离子液体的吸附性能研究

本文研究了介孔硅SBA-15对水中咪唑基离子液体[Bmim]Cl和[Bmim]OH的吸附行为。合成的SBA-15具有有序的二维六方介孔结构。研究发现升高温度会使SBA-15对离子液体的吸附量降低,吸附过程是放热过程。25℃下将吸附等温数据进行Langmuir和Freundlich方程线性拟合,相比之下Langmuir模型更适合用来描述SBA-15对两种离子液的吸附行为,SBA-15对[Bmim]Cl和[Bmim]OH最大吸附量分别为336.7和467.3mg·g-1。