Al-Ti共掺杂MoS2复合涂层润滑性能研究北大核心CSCD

采用磁控射频(RF)与磁控直流(DC)分别溅射金属铝靶,制备了润滑RF-Al-Ti/MoS2和DC-Al-Ti/MoS2复合涂层,并在真空条件下对制备涂层进行热处理以提高涂层耐磨损性能。结果表明,RF-Al-Ti/MoS2复合涂层中S/Mo原子比为1.55,有利于MoS2(002)面的形成,涂层平均摩擦系数低至0.1;由于RF-Al-Ti/MoS2复合涂层原子沉积效率更大,导致涂层结构致密,且RF-Al-Ti/MoS2复合涂层中Al原子含量高,有利于提升涂层抗氧化能力及耐磨损性能。对RF-Al-Ti/MoS2和DC-Al-Ti/MoS2复合涂层进行真空热处理,Ti和Al间扩散形成Ti-Al中间相进一步提升了涂层抗氧化性能,DC-Al-Ti/MoS2复合涂层磨痕形貌显示其耐磨损能力得到了明显提升;经500℃处理后,RF-Al-Ti/MoS2和DC-Al-Ti/MoS2复合涂层平均摩擦系数分别降低至0.08和0.07。总体上,射频溅射更有利于提升Al-Ti/MoS2复合涂层摩擦学性能。     

MoS2/MXene纳米复合物的研究进展

与单一的二维材料MoS2和MXene相比,MoS2/MXene纳米复合物具有优异且稳定的物理化学性能,受到了国内外研究者的广泛关注.本论文对MoS2/MXene纳米复合物的最新研究现状进行了综述.首先,阐述MoS2/MXene纳米复合物的制备方法及其优缺点,包括水热法、插层法和热退火法等.其次,介绍MoS2/MXene...     

MoS2填充PTFE复合材料的制备及性能研究

以MoS2、玻璃纤维(GF)、纳米Al2O3等为填料制备了聚四氟乙烯(PTFE)复合材料,研究了MoS2粒径对PTFE复合材料性能的影响。结果表明:在PTFE/MoS2、PTFE/(MoS2+GF)及PTFE/(MoS2+nanometerAl2O3)等复合材料中,随着MoS2粒径的减小,复合材料的磨耗量、摩擦系数、密度降低而硬度增加。     

MoS2/有序介孔碳复合材料的制备及性能研究

采用水热法合成了纯MoS2及MoS2/有序介孔碳复合材料(MoS2/OMC)。X射线衍射(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)及循环伏安曲线(CV)等分别用来表征样品的结构、形貌及电化学性能。实验结果表明,以钼酸钠和硫脲分别为钼、硫源合成的MoS2/OMC复合材料的性能较纯MoS2有明显提升。MoS2/OMC复合材料的首次放电容量达到1247mAh/g,第二、三次的放电容量分别为948mAh/g、894mAh/g,容量保持率为94%。二、三次充、放电曲线的近乎重合及高倍率下的高放电容量,亦表明该复合电极有极佳的循环稳定性及良好的可逆性。     

MoS2/有序介孔碳复合材料的制备及性能研究

采用水热法合成了纯MoS2及MoS2/有序介孔碳复合材料(MoS2/OMC)。X射线衍射(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)及循环伏安曲线(CV)等分别用来表征样品的结构、形貌及电化学性能。实验结果表明,以钼酸钠和硫脲分别为钼、硫源合成的MoS2/OMC复合材料的性能较纯MoS2有明显提升。MoS2/OMC复合材料的首次放电容量达到1247mAh/g,第二、三次的放电容量分别为948mAh/g、894mAh/g,容量保持率为94%。二、三次充、放电曲线的近乎重合及高倍率下的高放电容量,亦表明该复合电极有极佳的循环稳定性及良好的可逆性。     

自润滑耐磨Al/MoS2复合材料的初步研究

通过普通铸造的方法,制备了一系列的自润滑铝基/MoS2复合材料.借助于能谱分析和显微组织的观察证实了MoS2与基体的结合性能较好,MoS2以H型和"卜"字型分布在基体中.在磨损试验中,Al-Si合金 6%PbSn 低量MoS2有优于其他同类复合材料的耐磨性.Al/MoS2复合材料是一种很有潜力的自润滑耐磨材料.     

分步法制备MoS2/Ti3SiC2层状复合材料

研究了采用分步法制备MoS2/Ti3SiC2层状复合材料的工艺,其制备过程分2步进行.首先制备Ti3SiC2高纯粉,再在1 400℃,30 MPa条件下热压烧结制备MoS2/Ti3SiC2层状复合材料.其MoS2含量分别为2%,4%,6%,8%(w/%).用XRD分析比较4种不同MoS2含量的烧结试样的相组成,并测试维氏硬度和电导率.实验结果表明,当MoS2含量为4%时,MoS2/Ti3SiC2烧结试样的硬度达到7.83 GPa,且电导率达到10.05×106 S·m-1.MoS2含量再增加时,烧结试样的硬度有所增大,但电导率有所下降.     

MoS2/碳纤维对电极的制备及其在DSSCs中的应用

以钼酸、硫氰酸铵和碳纤维(直径0.4mm,长8cm)为原料,采用一步水热法制备了MoS2/碳纤维对电极。利用X射线衍射(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)及X射线能谱(EDX)对MoS2/碳纤维的微观组织结构进行了表征。采用循环伏安法(CV)对MoS2/碳纤维对电极的催化活性进行了研究。光电性能测试表明,基于MoS2/碳纤维对电极染料敏化太阳能电池(DSSCs)的光电转换效率为3.26%,大于基于Pt/碳纤维电极的光电转换效率2.93%,为低成本DSSC产业化技术研究奠定了基础。     

镍基MoS_2复合粉末等离子喷涂涂层的干滑动摩擦磨损性能

研究了 4种镍基MoS2 等离子喷涂涂层的干滑动摩擦磨损性能 ,探讨了涂层的结构及磨损面的形貌与涂层的磨损机制之间的关系 ,分析了MoS2 含量和载荷对涂层摩擦磨损的影响。研究表明 ,镍基MoS2 涂层具有很好的自润滑性能 ;MoS2 含量为 2 0 %的Ni/MoS2 涂层的摩擦磨损性能最佳     

新型聚苯硫醚复合涂层的制备和性能研究

用浸涂法制备了G/MoS2/Ekonol/PES/PPS多元复合涂层,以涂层结合强度为评价标准,采用混料回归实验优化设计了G/MoS2/Ekonol/PES/PPS复合涂层的涂料配方,用拉开法测定复合涂层的结合强度,并对结合表面进行了观察和分析,研究了涂料组成、涂层制备工艺参数和涂层厚度对涂层结合强度的影响。结果表明,用浸涂法能制得力学性能优良的G/MoS2/Ekonol/PES/PPS复合涂层;采用典型配方Ekonol:PES:PPS:G/MoS2:助剂=25:20:45:8:2(质量比)能够得到较大的结合强度。     

Thermogravimetric–differential thermal analysis of the solid-state decomposition of ammonium tetrathiomolybdate during heating in argon

The formation of MoS2 by thermal decomposition of ammonium tetrathiomolybdate (ATT) solids under an argon atmosphere has been studied by simultaneous thermogravimetric and differential thermal analysis. The sequential products for the decomposition upon heating to 700 °C is ATT (hydrated)(NH4)2MoS4(NH4)HMoS4H2MoS4MoS3 Mo2S5MoS2. MoS2 forms between 230 and 260 °C and remains stable up to about 360 °C when it tends to be oxidized by residual oxygen, if present in the atmosphere. These findings suggest that the synthesis of MoS2 from (NH4)2MoS4 via formation of MoS3 is not a direct process, as previously reported, but rather a complex process involving a number of intermediate products (NH4)HMoS4, H2MoS4 and Mo2S5 which have not been reported before. That these products are only specific to the very narrow temperature regimes as revealed suggests that they are very unstable and short lived, that their presence is transient in nature and thus that ex-situ characterization of them is normally difficult. The presence of these intermediate products, as justified experimentally, is further interpreted in terms of their mutual structural similarities which improve understanding as to why MoS2 can usually be prepared from ATT by thermal decomposition, as in this case, or by other techniques, such as anodizing. Laminar morphology of MoS2 is revealed by transmission electron microscopy and its crystal structure examined by selected-area diffraction. Further ex-situ examination by X-ray photoelectron spectroscopy of this end product supports the feasibility of preparing MoS2 from aqueous solutions by anodizing. © 1998 Kluwer Academic Publishers     

MoS_2与TiO_2一维纳米复合材料的制备与表征

本文采用气相还原法制备了MoS2包覆TiO2的一维纳米复合材料,首先用水热法制备TiO2纳米管,并制备前驱体(NH42)MoS4;用浸渍法将(NH4)2MoS4附着于TiO2纳米管表面;然后利用氢气还原前驱体得到MoS2包覆层。用X射线衍射(XRD)、扫描电镜(SEM)和透射电镜(TEM)表征所得产物的结构及微观形貌。结果表明当还原反应温度较高(≥600℃)时,产物呈烧结状态,而当反应温度为500℃时,可以得到表面均匀包覆MoS2的TiO2纳米管复合材料,其中包覆层MoS2的结晶程度较低。在此基础上,本文提出了该产物的生长模型,并对包覆前后的样品做荧光性能分析。     

纳米SiC浓度对Ni/纳米MoS_2基复合镀层结构和耐磨性能的影响

采用双脉冲复合电镀技术,在瓦特型镀液中,制备含纳米SiC的Ni/MoS2基复合镀层。研究纳米SiC浓度对复合镀层微观形貌、组织结构、显微硬度和摩擦性能的影响。结果表明:镀液中添加纳米SiC后,Ni/MoS2复合镀层的微观形貌产生明显的变化,随镀液中SiC浓度的增加,复合镀层表面致密度提高;镀液中纳米SiC浓度在1.0~1.5g/L时,组织由Ni+MoS2+SiC组成;纳米SiC为1.5g/L时,显微硬度达到最大,为505HV,摩擦因数为0.28,分别为纯Ni/MoS2的1.6倍和1/2。复合镀层的磨损机制以磨料磨损为主。     

摩擦表面MoS2润滑膜的显微结构分析

为探讨ＭｏＳ２／Ｎｉ复合材料的自润滑机理，采用薄膜分离技术从摩擦表面提取了ＭｏＳ２润滑膜，在透射电镜下研究其显微结构。结果表明，润滑膜中的ＭｏＳ２具有择优取向，其基础面科行于摩擦表观，形成了助于于润滑作用的织构。     

Hierarchical MoS<Subscript>2</Subscript> intercalated clay hybrid nanosheets with enhanced catalytic activity

Emerging hierarchical MoSR/pillared-montmorillonite (MoS2/PMMT) hybrid nanosheets were successfully prepared through facile in-situ hydrothermal synthesis of MoS2 within the interlayer of cetyltrimethylammonium bromide PMMT,and their catalytic performance was evaluated by the reduction reaction of 4-nitrophenol (4-NP) using NaBH4 as a reductant.Microstructure and morphology characterization indicated that MoS2/PMMT exhibited hybrid-stacked layered structures with an interlayer spacing of 1.29 nm,and the MoS2 nanosheets were intercalated within the montmorillonite (MMT) layers,with most of the edges exposed to the outside.The catalytic activity and stability of MoS2/PMMT were both enhanced by the MMT.With the MoS2/PMMT as the catalyst,the apparent reaction rate constant of the 4-NP reduction was 0.723 min-1 and was maintained at ～0.679 min-1 after five reaction cycles.The structural evolution of MoS2/PMMT and the possible catalysis mechanism for the reduction reaction of 4-NP were investigated.The as-prepared MoS2/PMMT hybrid nanosheets are promising candidates for catalytic application in the water-treatment and biomedical fields.The strategy developed in this study can provide insights for designing hybrid nanosheets with diverse heterogeneous two-dimensional (2D) nanomaterials.     

Status of aluminium in environmental compartments contaminated by acidic mine water

Investigations were conducted to characterize aluminium in the affected stream and soils downstream of a mine site discharging acidic mine water. The water-borne Al exhibited a highly non-conservative behaviour at water pH below 3.8 in the 0-3.9 km reach and a much more conservative behaviour in the reaches with higher water pHs downstream of the 3.9 km station. The concentration of water-borne Al was higher at the medium flow event than at the flood event in the 0-9 km reach while the opposite was observed for the 16-56 km reach. Transport of Al associated with suspended materials was only observed during the flood event. The amount of Al carried by per unit weight of suspended particles was smaller in the 0-16 km reach than in the 25-56 km reach. The sediment-borne Al increased downstream with maximum Al accumulation occurred in the 25-29 km reach. The residual Al dominated Al fractions in the streambed sediments. The NH(4)Cl-extractable Al in the affected soils decreased with increasing distance from the acidic irrigation water source. In contrast, both the water-extractable and total Al in the soils showed no clear distribution pattern. The NH(4)Cl-extractable Al was closely correlated with soil acidity while neither total Al nor water-extractable Al was correlated with soil acidity. The vertical distribution of NH(4)Cl-extractable Al was regulated by pH with certain influence from soil clay abundance.     

Preparation of MoO3/MoS2/TiO2 composites for catalytic degradation of methylene blue

Metastable hexagonal MoO3 microrods were grown from bulk MoS2 and used as support materials for MoS2 and TiO2 nanoparticles. The hybrid composites that consisted of MoO3, MoS2, and TiO2 were prepared at a low temperature using the one-step synthesis method. The crystallinity and morphology of the MoO3/MoS2/TiO2 composites that were prepared using HNO3 and titanium tetraisopropoxide were compared with those of the MoO3/MoS2 composites that were prepared without titanium tetraisopropoxide. Titanium isopropoxide facilitated the formation of the MoO3 microrods from the oxidation of the bulk MoS2. The desired MoO3/MoS2/TiO2 composites were obtained using 0.5 g of bulk MoS2, 3-4 ml of HNO3, and 0.367 ml of titanium tetraisopropoxide. The MoO3/MoS2/TiO2 composites that were treated with ultrasonic waves showed rapid degradation of the methylene blue solution (2 x 10(-4) M) in the dark and good photocatalytic ability under ultraviolet light irradiation. The decomposition of methylene blue depended on the composition of the composite.     

A new hydrothermal route for synthesis of molybdenum disulphide nanorods and related nanostructures

A simple approach to prepare nanorods of Molybdenum Disulphide (MoS2) using hydrothermal method by reacting aqueous solutions of (NH4)6Mo7O24.4H20, C2H4NS and Na2S2O4 at 190 degrees C for 24 h is described. The hydrothermal product has been subsequently subjected to the thermal treatment in nitrogen atmosphere at 675 degrees C for 6 h and characterized. X-ray diffraction (XRD) of the hydrothermal product indicated the formation of MoS2 relatively with much lower crystallinity compared to when it thermally treated. Energy dispersive analysis (EDX) was done to know the chemical composition of the product. TEM showed onset growth of MoS2 nanorods within the hydrothermal products itself and in thermally treated products it was prominent with the diameter of the nanorods ranging between 10-20 nm. Photoluminescence spectra MoS2 nanorods shows an intense absorbance at around 429 nm. TGA of the MoS2 nanorods in air and nitrogen atmosphere has also been studied. The extent of formation of MoS2 from the precursors obtained at 190 degrees C for duration of 12, 18, and 24 h and annealed at 675 degrees C for 6 h under nitrogen atmosphere is also demonstrated based on XRD data.     

纳米-MnO2的制备及其性能研究

用溶胶－凝胶法制备纳米级α－ＭｎＯ２,并对实验条件进行了讨论．对所得的样品进行了ＸＲＤ、ＩＣＰ、ＴＥＭ、化学分析、恒流放电、循环伏安等一系列测试,并与国际一号样（Ｉ．Ｃ．ＮＯ．１电解二氧化锰）相比较．虽然纳米级α－ＭｎＯ２的单独放电性能并不好,但是当纳米级α－ＭｎＯ２以一定比例与Ｉ．Ｃ．Ｎｏ．１号样混合时,在浅度和深度放电区内的放电容量都比Ｉ．Ｃ．Ｎｏ．１高．     

二硫化钼粉体的表面改性研究

为了得到良好亲油性的二硫化钼(MoS2)粉体,采用湿法改性工艺,分别以硅烷偶联剂(KH570)、硬脂酸(SA)及其复合改性剂对MoS2粉体进行表面改性,并进行粉体悬浮液的浊度、活化指数等分析。结果表明:改性MoS2粉体疏水亲油性提高;对改性前后的MoS2粉体进行了FT-IR及XRD的结构表征,结果表明,粉体粒子表面成功地被有机物包覆;将改性MoS2粉体填充于聚苯硫醚(PPS)、聚丙烯(PP)复合材料,力学拉伸试样断口的SEM分析表明:改性MoS2在PPS-PP复合材料中无团聚且分散均匀。