三维炭/还原氧化石墨烯纳米片的制备及其电化学性能

采用水热合成法,将间苯二酚甲醛树脂涂覆在还原氧化石墨烯片层上,经冷冻干燥及炭化后构筑三维炭/还原氧化石墨烯纳米片。使用SEM、TEM、FTIR、XPS等对样品的形貌与结构进行表征,利用循环伏安、恒流充放电及电化学阻抗法测试了样品的电化学性能。结果表明,间苯二酚甲醛树脂成功将还原氧化石墨烯片包覆,二者构筑的三维炭/还原氧化石墨烯复合纳米片厚度为25nm;当循环伏安测试扫描速率为20mV/s时,三维炭/还原氧化石墨烯纳米片电极材料的比电容分别为还原氧化石墨烯与间苯二酚甲醛树脂炭电极材料相应值的1.8和2.8倍;在0.2A/g的充电电流密度下,三维炭/还原氧化石墨烯纳米片电极材料比电容为154.4F/g。     

Nano-mechanical and tribological properties of copper matrix compositesreinforced by graphene nanosheets

The impacts of graphene nanosheets content on microstructure, nano-mechanical and tribological properties of the copper matrix composites were investigated. The graphene nanosheets randomly distributed in copper matrix, which obviously hindered its grain growth. The elastic modulus and nano-hardness of the copper matrix composite with 0.2 wt% graphene nanosheets were enhanced 47.5% and 54.7% compared to these of pure copper, respectively. The average creep degree(5.1%) was lower than that(11.8%) of pure copper in holding stage. The creep rate(ca. 0.016 nm/s) decreased 10 times as that(ca. 0.16 nm/s) of pure copper in steady-state creep. The tribological performances were improved dramatically with increase of graphene nanosheets content.     

超级电容器极化电极材料的研究进展

超级电容器作为储能元件，具有重要的战略意义，与常规的电解电容器相比，明显地提高了比容量、比能量；而与电池相比，虽然比能量较低，但其比功率却是电池的数量级倍数。目前用于制备超级电容在的极化电极材料主要分为碳素材料、金属氧化物材料和导电聚合物材料。简要地介绍了这三类材料的制备、结构、改性、工作原理以及电化学特性，评述了这三类材料的研究进展，这三类材料制作的电容器具有超大功率，长循环寿命等特点，为电动车（EV）以及其他储能器的发展奠定了基础。     

Electrochemical reduction of graphene oxide films: Preparation, characterization and their electrochemical properties

Graphene oxide (GO) film was electrochemically reduced by a cyclic voltammetry technique in 6 mol L-1 KOH aqueous solution.Electrochemically reduced graphene oxide (ER-GO) film was characterized by X-ray diffraction,X-ray photoelectron spectroscopy,atomic force microscopy,and Raman spectroscopy.The oxygen content (with the O/C atomic ratio of 1.29%) was significantly decreased after electrochemical reduction.The ER-GO film exhibited a specific capacitance of 152 F g-1 at the current density of 5 A g-1 and a good rate capability.Furthermore,the ER-GO film showed an excellent cycling ability.The capacitance retention remained 99% after 3000 cycles at the current density of 10 A g-1.     

湿法制备纳米二氧化锰及其电化学性能的研究

分别用氧化法、还原法和氧化还原法在溶液中反应制备了MnO2粉末.用X射线衍射(XRD)、扫描电子显微镜(SEM)、循环伏安、交流阻抗、恒电流充放电等测试方法对3种样品结构、形貌和电化学性能进行分析比较.研究表明:三样品均为无定型MnO2,形貌呈团聚的球形,其中用氧化法制备的MnO2具有良好的电容性能和放电容量.     

Ag2O超级电容器的研究

用固相合成法制备Ag2O作为超级电容器材料,通过循环伏安与恒流充放电等测试手段对Ag2O电极及与作为负极的活性炭电极组成的电容进行分析.结果表明,在7mol·L-1KOH电解液中,Ag2O电极在0.15～0.35V(相对于Hg/HgO)的电压范围内表现出了法拉第电容特性.在不同电流密度下,电极比容量达427.3～554.9F·g-1,Ag2O/活性炭单体电容器比电容为42.5～61.65F·g-1.同时还对正极中Ag2O的含量及导电剂对Ag2O/活性炭单体电容器性能的影响进行了研究.     

超级电容器过渡金属氧化物电极材料研究进展

与传统电容器相比,超级电容器具有循环性能优异、大倍率充放电特性好、能快速充放电和环境友好等优点,目前在众多领域中都受到了研究者的关注.超级电容器电极材料主要包括3大类,即碳基电极材料、过渡金属氧化物电极材料及导电聚合物电极材料.鉴于超级电容器具有广阔的应用前景,综述了超级电容器过渡金属氧化物电极材料的研究现状,并对其今后可能的发展方向进行探讨.     

Recent advances in graphene based photoresponsive materials

Recent scientific interests reveal that graphene, with its flexibility, chemical stability, thermal conductivity,unique electronic band structure and optical transmittance, has emerged as the novel supporting material for nanocomposites for various applications. Research interests have flourished regarding decoration of conventional materials with modified graphene for achieving better optical properties. More concern is given for achieving improved photoresponse with graphene as the supporting material. The giant electron mobility and transparency of graphene enables the photo-induced electron transfer in the hybrid material, resulting in enhanced behaviour. Graphene oxide is able to effectively convert near infrared energy into heat, potentially acting as a photo-thermal switch. They act as potential candidates for photo-catalysts, sensors, photo-current switching,photo-detectors and other optical applications. In this review, we summarized the recent developments on fabrication and properties of graphene based photoresponsive materials.     

Pt-induced electrochemical growth of ZnO rods onto reduced graphene oxide for enhanced photodegradation performance

Photodegradation of organic pollutants over semiconductor catalysts is considered to be a viable method for wastewater treatment.Of the different semiconductor photocatalysts,ZnO has been widely used for the photodegradation of organic pollutants.Meanwhile,graphene is being actively investigated as a cocatalyst for such processes.The high carrier transport rate of graphene can favor the transfer of photoexcited electrons,while the increased specific surface area provides adsorption sites for the organic effluent molecules,thereby improving overall photocatalytic activity.Therefore,in this study,Pt–ZnO–reduced graphene oxide(RGO)rods with different RGO contents are synthesize during a novel Pt-induced electrochemical method,where ZnjZnO acts as the anode and PtjH2OjH2acts as the cathode.The photocatalytic degradation activity of the Pt–ZnO–RGO rods is remarkably improved under UV–visible light irradiation,with the optimum loading RGO content of 1 wt%.     

自支撑GN/MnO2复合材料的制备及其 电容性能研究

本文通过水热辅助真空冻干法制备得到了可以自支撑的石墨烯/二氧化锰(GN/MnO_2)复合材料,利用X射线衍射仪(XRD)和扫描电子显微镜(SEM)分别对复合材料结构与形貌进行表征,并以复合材料为工作电极,组装成对称电容器,探究反应物质量比与电解液对材料电化学性能的影响,结果表明:在KOH电解液中,复合材料的比电容最大;当反应物质量比为1∶4时,该复合材料比电容可以达到224F/g(电流密度为1A/g).     

影响脉冲电流法制备MnO2超级电容器电极性能的因素

通过正交实验法研究了影响脉冲电流法合成MnO2超级电容器电极材料性能的影响因素,发现影响效果由大到小依次为:脉冲电流关断时间,醋酸锰水溶液浓度,脉冲电流密度,脉冲电流导通时间.在正交实验法得出的最优条件下,即醋酸锰浓度为0.5 mol/L,电流密度为250 A/m2,导通时间为0.01 s,关断时间为0.2 s,所制备的MnO2薄膜电极材料表面具有丰富的纳米球结构,在10 mV/s的扫描速率下,3 mol/L的KCl溶液作为电解液,比容量可以达到575 F/g,并且在2 000mV/s的快速充放电条件下,仍然能够保持良好的电容特性.     

物理化学综合实验设计——纳米MnO_2作为超级电容器电极材料的研究

探索了将纳米 Mn O2 电极的电容性质研究作为物理化学综合实验的可行性 .循环伏安和恒电流充放电实验表明 ,纳米 Mn O2 电极具有较为优良的电容性质 ,用 10 m A和 5 0 m A恒流充放电时 ,Mn O2 电极的比电容分别为2 0 3.6 F/ g和 15 0 F/ g;分别连续充放 5 0周和 2 0 0周后 ,容量保持率仍分别为最初的 91.2 %和 90 .5 % .     

聚苯胺纳米纤维的界面聚合法合成及电化学电容行为

利用盐酸和四氯化碳的水/油两相界面,通过界面聚合法合成具有良好纳米纤维结构的聚苯胺,用这种聚苯胺纳米纤维为活性物质制备电极,以1 mol/L H2SO4水溶液为电解液组装超级电容器,通过恒电流充放电、循环伏安、交流阻抗等技术研究其电化学电容行为。研究结果表明,合成的聚苯胺的直径为50～100 nm,长度为500nm至几微米不等,且纤维之间相互交织缠绕,形成网状形貌;聚苯胺纳米纤维电极材料的功率特性与循环性能优于用传统化学氧化法合成的颗粒状聚苯胺材料的性能,在5 mA放电电流下,其比电容可达317 F/g,20mA放电电流下比电容仍维持300 F/g左右,500次循环容量衰减在4%以内。     

A fluid dynamics route for producing graphene and its analogues

A novel fluid dynamics route for scalable and efficient production of graphene and its analogues is demonstrated. Atomic force microscopy and transmission electron microscopy analyses strongly suggest that the bulk layered materials （graphite, BN, MoS2, and WS2） are efficiently exfoliated into individual layers containing mono-and few-layer nanosheets. Computational fluid dynamics analysis indicates that multiple fluid dynamics events are responsible for efficient exfoliation. Cavitation and pressure release can generate normal force for exfoli- ation. The velocity gradient-induced viscous shear stress, the turbulence-induced Reynolds shear stress, and shear effects stemmed from turbulence and flow channel-induced collisions can generate lateral force for exfoliation, resulting in theses bulk layered materials self-exfoliation down to single or few layers through their intrinsically lateral self-lubricating ability.     

石墨烯基气凝胶的制备及其超电容性能研究

采用氧化石墨烯自组装法制备出氧化石墨烯气凝胶(GOA),并采用高温(1100℃)氢气还原进一步制备石墨烯气凝胶(GA)。采用氮气吸附、FT-IR、元素分析和电化学测试等手段对其进行表征。结果表明:制备的两种气凝胶具有较高的BET比表面积(均约为870 m2·g-1);GOA表面具有丰富的含氧官能团,GA表面氧含量极低;GOA与GA的碳氧摩尔比分别为1.7和69.9;在低电流密度下(0.2 A·g-1),具有高表面官能度的GOA比电容达155.8 F·g-1,而低表面官能度的GA表现出高倍率的超电容性能。     

Reduced graphene oxide wrapped 3D-ultrathin CoS2 nanoflakes as an absorbing material with enhanced microwave absorption

Novel 3D-ultrathin CoS₂ nanoflakes wrapped by reduced graphene oxide (CoS₂/RGO) were successfully prepared via a facile method. The morphology and structure of the materials were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. The microwave absorption properties of the CoS₂/RGO composites were also investigated. The composites exhibited optimal microwave absorption properties at a CoS₂/RGO loading of 20 ?wt.% in paraffin matrix, with a reflection loss (R_L) value of ?36.5 ?dB at 12.1 ?GHz and a thickness of 2.0 ?mm. Furthermore, CoS₂/RGO composites have an excellent absorption bandwidth (reflection loss below ?10 dB) of 6.5 ?GHz. The results indicate that the RGO-wrapped 3D-ultrathin CoS₂ nanoflakes have a broad microwave absorption bandwidth, strong absorption, and are the candidates for the application as the advanced microwave absorbers.     

新型碳微球制备和电化学性质研究

以氨水作为催化剂,间苯二酚和甲醛为前驱体制备单分散酚醛(resorcinolformaldehyde,RF)树脂微球和碳微球.采用循环伏安法、电化学交流阻抗和恒电流充放电等方法对由RF树脂得到的碳微球的电化学性能的测试表明,其可以作为超级电容器电极材料.在扫描速率为1mV·s-1时,比电容为175.9F·g-1,电阻为0.5Ω,循环500圈后仍保持94.4%的电容量,具有优异循环寿命.结果表明,由酚醛树脂制备的单分散碳微球作为超级电容器的电极材料具有降低离子运输阻力和提高超级电容器稳定性的功能.     

超级电容器电极材料纳米Fe3O4的制备及其性能研究

采用化学共沉淀法制备了纳米Fe3O4,系统考察了n(Fe3+):n(Fe2+)、反应pH值、熟化温度等对纳米Fe3O4生成的影响,从而确定最佳反应条件.将纳米Fe3O4应用到超级电容器上,研究了其作为电容器电极材料的电化学性能.结果表明:在最佳反应条件下,制备出的纳米Fe3O4的晶体结构完整;经电化学性能测定,Fe3O...     

镍基电极材料在超级电容器中的制备与应用

Ni因其价格低廉和对环境友好,被视为具有发展潜力的超级电容器电极材料之一;且它与其他电极材料复合可以有效阻止团聚反应的发生,能大大改善材料的电化学性能。近年来Ni的（氢）氧化物与碳材料、聚合物等复合制备新的电极材料已经成为储能领域研究的热点。介绍了Ni的化合物作为电极材料储能的机制以及在复合电极材料中的应用,综述了近年来国内外报道的各类镍基复合电极材料的研究进展,并对其今后的发展趋势进行了展望。