氢氧化钾活化法制备淀粉活性炭电极材料

以KOH为活化剂、氧化交联淀粉为原料制备了超级电容器用电极材料.最佳工艺条件是:活化温度850℃,活化保温1.5 h,碱炭质量比为2∶1.在该条件下制备的淀粉活性炭具有较高的比表面积(1 493.9 m2/g)和高比容量(218 F/g).通过氮吸附表征其孔结构.以其作为电极材料组装在模拟超级电容器中进行充放电性能和循环伏安法测试,在300 mg/g KOH水系电解质溶液、较高电流密度下,最佳制备工艺条件下所制备的活性炭表现出较好的电容特性.     

Ultrafastly activated needle coke as electrode material for supercapacitors

The uniform porous structure makes activated porous carbons(APCs) superior electrode material.Traditionally,APCs are produced by a combination of time-consuming high-temperature heat treatment and activation,with a production time of up to several hours.The produced APCs have relatively low specific surface area(SSA) and porosity.Therefore,the electrochemical performance is poor,which limits its application in high-power energy storage devices.Here,APCs materials are directly synthesized by a hi...     

Scalable synthesis and electrochemical performance of mesoporous graphene from calcium carbonate by magnesiothermic reaction

A novel scalable synthetic method of mesoporous graphene has been developed using the compressed mixture of Mg and excess CaCO₃ in a closed container. The generated solid oxide and unreacted CaCO₃ could act as mesopore-forming agents, and the closed container could prevent the carbon dioxide from CaCO₃ flow away. As a result, the graphenes with a large number of 2–30 ?nm mesopores and high utilization ratio of Mg achieved. The graphenes had high specific surface area and excellent electrochemical performance. In particular, the Mg utilization ratio was up to 53.3% in the preparation of graphene using 2:1 CaCO₃/Mg at 700 ?°C, which is superior to previous researches. The obtained mesoporous graphene exhibited high specific surface area of 743.7 ?m² ?g^-1, large specific capacitance of 140 ?F ?g^-1, and high capacitance retention rate of 64.3%.     

Preparation of mesoporous MgO-templated carbons from phenolic resin and their applications for electric double-layer capacitors

Mesoporous carbons were synthesized using thermoplastic phenolic resin (PF) as carbonaceous precursor and magnesium citrate as template precursor. Pore structure was determined as ink-bottle-like geometry through TEM, N2 adsorption analysis combined with TG curves. The porous carbons prepared were then applied as electrode material for electric double-layer capacitors. The capacitor performance was examined in 30 wt% KOH aqueous solution by cyclic voltammetry and galvanostatic charge/discharge measurements. The carbon prepared with MgO/PF mass ratio of 8/2 had a BET surface area of 1920 m² g^?1 and exhibited a capacitance of 220 F g^?1 at a current density of 50 mA g^?1. Besides, the carbon with the ratio of 4/6 had the optimize proportion of mesopores, which ensures its good rate performance that up to 98.3%, expressed as the ratio of the capacitance measured at 1000 mA g^?1 against that at 50 mA g^?1.     

Granular activated carbons from palm nut shells for gold di-cyanide adsorption

Granular activated carbons were produced from palm nut shells by physical activation with steam. The proximate analysis of palm nut shells was investigated by thermogravimetric analysis, and the adsorption capacity of the activated carbons, produced as a result of shell pyrolysis at 600℃ followed by steam activation at 900℃ in varying activation times, was evaluated using nitrogen adsorption at 77 K. Applicability of the activated carbons for gold dicyanide adsorption was also investigated. Increasing the activation hold time with the attendant increase in the degree of carbon burn-off results in a progressive increase in the surface area of the activated carbons, reaching a value of 903.1 m2/g after activation for 6 h. The volumes of total pores, micropores, and mesopores in the activated carbons also increase progressively with the increasing degree of carbon burn-off, resulting from increasing the activation hold time. The gold di-cyanide adsorption of the activated carbons increases with the rise of pore volume of the activated carbons. The gold di-cyanide adsorption of palm nut shell activated carbon obtained after 6-h activation at 900℃ is superior to that of a commercial activated carbon used for gold di-cyanide adsorption.     

Development of N-doped carbons from zeolite-templating route as potential electrode materials for symmetric supercapacitors

N-doped carbons were fabricated from zeolite-templated carbon via modification with melamine and mild KOH activation. The N-doping treatment and KOH activation slightly lowered the surface areas of pristine zeolite-templated carbon; nonetheless, N-doped carbons with a lower surface area exhibited much higher capacitance and cycling stability as fabricated into symmetric supercapacitor. Significantly, N-doped carbon obtained at 700℃ showed a capacitance of 45.7 F/g at 0.1 A/g and 42.0 F/g at 10 A/g for the fabricated supercapacitor with 6 M KOH electrolyte, with 92% retention of initial capacitance as current density increased up to 100-fold. This performance was attributed to the dual contribution of electric double-layer capacitance and pseudo-capacitance. The assembled supercapacitor also exhibited excellent cycling stability, with 91% capacitance retention at 10 A/g after 10000 cycles.     

Activated carbon derived from rice husk by NaOH activation and its application in supercapacitor

Four activated carbon(AC) samples prepared from rice husk under different activation temperatures have been characterized by N2adsorption–desorption isotherms, thermogravimetric analysis(TGA–DTA), Fourier transform infrared spectroscopy(FTIR) and scanning electron microscopy(SEM). The specific surface area of AC sample reached 2681 m2 g 1under activation temperature of 800 1C. The AC samples were then tested as electrode material; the specific capacitance of the as-prepared activated carbon electrode was found to be 172.3 F g 1using cyclic voltammetry at a scan rate of 5 mV s 1and 198.4 F g 1at current density 1000 mA g 1in the charge/discharge mode.& 2014 Chinese Materials Research Society. Production and hosting by Elsevier B.V. All rights reserved.     

晋城超低灰无烟煤制备高比表面积颗粒活性炭的试验研究

以晋城无烟煤为原料,先经浮选和酸洗脱灰,得到灰分1.2%的超低灰无烟煤,再将其与活化剂KOH按比例混合、粘结成型,并经活化处理制备高比表面积活性炭。主要考查了碱炭比、活化温度和活化时间对活性炭比表面积及收率的影响。结果表明,晋城超低灰无烟煤制备高比表面积活性炭的最佳工艺条件为:碱炭比5∶1,活化温度800℃、活化时间1 h,活性炭的BET比表面积为1 800.71 m2/g,孔径大小分布于0.3～5 nm之间,以微孔为主。     

分级多孔纳米炭纤维的结构及电容性能

以酚醛树脂为碳源、PVP为纺丝助剂、纳米MgO颗粒为模板剂,通过静电纺丝法制得酚醛树脂基纳米炭纤维,经过炭化、KOH活化、酸洗后得到分级多孔纳米炭纤维,利用SEM、XRD、XPS、拉曼光谱仪及氮气吸脱附实验,对所制多孔纳米炭纤维的结构和形貌进行表征,并将其作为模拟电容器的电极,利用循环伏安、恒电流充放电及交流阻抗方法测试了材料的电化学性能。结果表明,KOH活化引入了数量可观的微孔,所得纳米炭纤维表现出明显的"微孔-中孔-大孔"分级孔分布的特点,其比表面积达到1058.4m~2/g,总孔容为1.64cm~3/g。电化学测试结果表明,所制分级多孔纳米炭纤维在6mol/L KOH电解液中显示出优异的电容性能,在0.2A/g的电流密度下,其放电比容量达到198F/g,在20A/g电流密度下,电容保持率达到65%。     

炭气凝胶微球的物理活化与化学活化比较

以炭气凝胶微球为原料,分别采用CO2和KOH作为活化剂,研究物理活化和化学活化对炭气凝胶微球孔结构和电化学性能的影响差异,探讨CO2和KOH的活化机理。结果表明,CO2和KOH活化均能有效改善炭气凝胶微球的孔结构,比表面积最高可达1 320 m2/g;同时显著提高材料的电化学性能,活化后的比电容最高可为活化前的3倍。结果还表明两种方法的活化机理不同,CO2活化,有利于保持炭气凝胶微球的中孔,为电子进出提供大量的快速通道,提高传质速率;KOH活化,对炭气凝胶微球的微孔形成非常有利,可增大电化学活化表面,提高电化学性能。     

MOF基多孔炭的制备及其在超级电容器中的应用

金属有机框架材料(MOFs)由于其具有较高的比表面积,可调节的孔隙结构,以及结构、功能多样性,使其作为前驱体在电化学等方面具有广阔的应用前景.采用水热法合成了金属有机框架材料[Zn₃(bpdc)₃(bpy)]·2DMF·4H₂O](ZBB),并以此为前驱体,通过炭化-活化法制备了多孔炭ZBBC-T-A,研究了不同炭化温度,不同的炭碱比对多孔炭微观结构及电化学性能的影响.结果表明:多孔炭ZBBC-800-1∶3是以微、介孔为主,且最大比表面积达2 294.6 m² ·g^-1;以6 mol·L^-1 KOH为电解液,在电流密度为1 A·g^-1时,其比电容为304.8 F·g^-1;电流密度从1 A·g^-1增加到10 A·g^-1时,电容损失率为21.26%;在1 A·g^-1的电流密度下,经过5 000次循环后,电容保持率为95.85%.其能量密度为8.06 Wh·kg^-1.     

Flexible free-standing polyaniline/poly(vinyl alcohol) composite electrode with good capacitance performance and shape memory behavior

The increasing demand for portable and flexible energy storage devices drives the development of flexible electrodes and electrolytes. The aim of this work is to fabricate the flexible free-standing polyaniline/poly(vinyl alcohol)(PANI/PVA) composite electrode with good capacitance performance and shape memory behavior. The electrodes were fabricated by chemical oxidation polymerization of aniline in porous PVA(P-PVA) films. The morphology, electrochemical and mechanical properties of PANI/P-PVA...     

微波改性活性炭吸附1,2-二氯乙烷的性能研究

采用微波高温烧结炉分别在600℃,700℃和800℃下对商业活性炭进行改性,利用比表面积及孔径分析仪、Boehm滴定、傅立叶变换红外光谱比较分析活性炭的比表面积和孔结构、表面官能团等物化性质.以1,2-二氯乙烷为吸附质进行固定床吸附实验.研究表明:改性后活性炭表面酸性基团减少,碱性基团随温度升高增多;比表面积、孔容减小,微孔比表面积增加;活性炭对1,2-二氯乙烷的吸附量排序为:AC-800AC-700AC-600AC-0;灰色关联度分析结果表明:改性活性炭的物理结构特性对吸附量的影响大于表面基团;D-R模型和动力学模型拟合结果都表明活性炭对1,2-二氯乙烷的吸附主要为物理吸附.     

废弃菌棒的热解及其生物炭的活化

用废弃的菌棒作为原料,利用高温管式炉对其进行热解及活化,探究废弃菌棒在不同热解温度下的热解性能及不同活化条件下的活化性能,并对最优条件下获得的活性炭进行表征,结果表明：热解终温的升高有利于制备富氢燃气,热解终温为900℃时气体产量最大（489 L/kg）,其中H₂占55.55%,CO占31.93%,CH₄占8.52%;选择热解终温为600℃比较有利于液相的生成,此时液相产率为29.50%;选择400℃的热解终温有利于生成热值较高且产率较高的固体燃料,此时炭产率为48.23%,热值20.66 MJ/kg。此外,以热解终温600℃、升温速率20℃/min、热解反应时间1 h条件下制得的生物质炭为原料,在不同条件下进行活化,发现当碱碳比为1、活化时间为1 h、活化温度为800℃时制备的活性炭具有最佳的吸附性能,此时活性炭产率为31.20%,比表面积为1 659.812 m²/g,亚甲基蓝脱色能力为615.32 mg/g,碘吸附值达到1 563.90 mg/g。     

表面改性活性炭的制备及其去除污水中Cd~(2+)的试验研究

以花生壳生物质炭(PSB)为原料,采用KOH活化法制备了比表面积为461 m2·g-1的花生壳活性炭(K-PSB),利用氮气吸附脱附等温线、SEM等对样品进行了表征,并将孔隙结构发达的花生壳活性炭用于重金属Cd2+的吸附,考察反应时间、溶液p H值、花生壳活性炭的投加量等对Cd2+吸附的影响。结果表明:随着吸附时间的推移,Cd2+的吸附量逐渐增加直至达到平衡,当Cd2+浓度为50 mg·L-1,PH值等于6,投加量为1 g·L-1时,花生壳活性炭对Cd2+的吸附效果最佳;该吸附是一个吸热反应,随着温度的增加,吸附量逐渐增大。     

酒糟渣活性炭的制备及其表征

以酒糟渣为原料,采用浓酸炭化法,KOH活化法制备了活性炭。考察了活化温度、活化时间、碱炭质量比以及酒糟渣／KOH质量比对活性炭的影响。采用SEM、BET、FT-IR、XRD对其物化性能进行了表征分析。结果表明：在活化温度为800℃、活化时间为3h、碱炭质量比为3：1、酒糟渣／KOH质量比为4：1时制备的活性炭性能最优。该酒糟渣活性炭吸附孔容为0．88248cm3／g,DFT比表面积为3654．9m3／g,碘吸附值为2216．3mg／g,亚甲基蓝吸附值为389．40mL／g。     

Rational design of MnS nanoparticles anchored on N,S-codoped carbon matrix as anode for lithium-ion batteries

The manganese sulfide (MnS) has attracted more attention as anode material on energy storage and conversion field, owing to its high theoretical capacity (616 ​mA ​h ​g⁻¹) and good electrochemical activity. However, low electronic conductivity and large volume expansion during charge-discharge processes have limited its further application. In order to address above mentioned problems, the composites, MnS nanoparticles embedded in N,S-codoped porous carbon skeleton (named as MnS/N,S–C composites), herein have been prepared successfully using metal organic framework (Mn-NTA) as template. The porous carbon skeleton not only can enhance electrode conductivity, but also relieve volume expansion during charge-discharge processes. Thus, the rational design towards electrode architectures has endowed MnS/N,S–C nanocomposites with superior electrochemical performance, which delivers the specific capacities of 676.7 ​mA ​h ​g⁻¹ at the current density of 100 ​mA ​g⁻¹.     

Flexible micro-supercapacitors fabricated from MnO2 nanosheet/graphene composites with black phosphorus additive

Supercapacitors are widely used for powering flexible/wearable electronics owing to their excellent charge storage capabilities. In this study, MnO₂ nanosheets were grown on the surface of graphene using a simple water bath method to prepare graphene/MnO₂ composites for fabricating supercapacitors. In addition, two-dimensional black phosphorus was introduced as an additive into the electronic ink based on the as-prepared graphene/MnO₂ composites. The characterization and electrochemical analyses results showed that adding black phosphorus considerably improved the capacitive performance of the material, yielding a high specific capacitance of 241.5 ?F ?g^-1 at 0.1 ?A ?g^-1 and an impressive rate capability improvement from 52.5% to 80.3%. Then the micro-supercapacitor having an area-specific capacitance of 20.15 ?mF ?cm^-2 at a scanning rate of 2 ?mV ?s^-1 was utilized to demonstrate the practical applicability of this material. To further evaluate the practical applicability of this micro-supercapacitor, the micro-supercapacitor was integrated with a flexible thin-film pressure sensor on paper and cloth through screen printing.     

碱炭比对活性炭孔结构及电容特性的影响

以酚醛树脂为原料、KOH为活化剂制备双电层电容器用高比表面积活性炭．考察KOH与酚醛树脂炭的质量比对所制得的活}生炭的吸附性能、孔径分布和比电容的影响．实验结果表明,随着碱炭比的增大,所得活性炭的BET比表面积、总孔容积和中孔容积不断增大,碘吸附值和亚甲基蓝吸附值也不断增大,比电容则先增大后减小并在碱炭比为4时达到最大值74．2F／g．以这种高比表面积活性炭组装成的电容器具有良好的充放电性能和循环性能,既能在大电流下快速充放电也能在小电流下缓慢充放电。     

介孔活性炭的制备及其高湿储甲烷性能

天然气是一种清洁能源,作为汽车代用燃料以及从天然气开采地到各用户单位之间的运输,都需要有效的存储技术.天然气水合物（NGH）能够降低甲烷存储的成本,而多孔材料孔内生成气体水合物能够有效提高储气密度,本研究目的是合成在孔内能够生成甲烷水合物的低成本高性能吸附剂.首先以农业废弃物玉米芯为原料,采用KOH活化法制备活性炭,其湿储甲烷最优合成条件为：在400,℃炭化30,min,碱炭质量比5∶1、850,℃活化1.0,h合成出C-8高性能活性炭,其孔容达到2.264,cm^3/g,比表面积为2 993,m^2/g,孔径分布主要集中在2～3,nm.合成的C-8是非常好的甲烷湿储吸附剂,在水炭比为3.68时在9.40,MPa下CH4达到最大吸附量为69.66%,是其干燥样品最大吸附量的3.25倍,并可以在较大压力范围内使存储的甲烷提供平稳的放气量,有望作为新型的甲烷水合物存储吸附剂应用于天然气汽车上.