玉米芯活性炭的制备及其电化学性能研究

以玉米芯为原料,采用KOH活化法制备超级电容器用活性炭。利用低温氮气吸附及恒流充放电、循环伏安、交流阻抗等方法测定活性炭的孔结构及其用作电极材料的电化学性能。研究了脱灰对玉米芯活性炭孔结构及其电化学性能的影响。结果表明,在碱炭比3∶1、活化温度为800℃、活化时间为1h的条件下,可以制备出比表面积为2019m2/g、总孔容为1.084cm3/g、中孔率为15.6%的高比表面积活性炭。玉米芯经脱灰处理可以显著改善其所制活性炭的孔隙发达程度和中孔分布,脱灰玉米芯活性炭的比表面积、总孔容及中孔率分别可达2311 m2/g、1.246cm3/g和26.0%。玉米芯活性炭电极材料在3mol/L KOH的电解液中具有良好的电化学性能,其比电容量可达253F/g。脱灰玉米芯活性炭电极的比电容量更高(可达278F/g),比电容提高9.9%,且内阻更小。     

利用核桃壳制备高比表面积活性炭电极材料的研究

以核桃壳为原料,采用KOH活化法制备活性炭,并将其用作超级电容器电极材料。利用N2吸附和扫描电镜(SEM)表征活性炭的孔结构及表面形貌,系统研究碱炭比(KOH与核桃壳炭化料的质量比)对活性炭孔结构的影响,并采用恒流充放电及循环伏安等测定核桃壳活性炭电极材料在3mol/L KOH电解液中的电化学性能。结果表明,随着碱炭比的增大,活性炭的比表面积、总孔容及中孔比例先逐渐增大后稍有减小。当活化温度为800℃,活化时间为1h,碱炭比为4时,可制备出比表面积为2404m2/g,总孔容为1.344cm3/g,中孔比例为28.6%,孔径分布在0.7~3.0nm之间的高比表面积活性炭。该活性炭用作超级电容器电极材料具有良好的大电流放电特性和优异的循环性能,电流密度由50mA/g提高到5000mA/g时,其比电容由340F/g降低到288F/g,经1000次循环后,比电容保持率为93.4%。     

微波法煤基活性炭的制备及其电化学性能研究

以内蒙古优质褐煤为原料,KOH为活化剂,采用微波加热活化法制备超级电容器用活性炭,利用低温氮气吸附及恒流充放电、循环伏安等方法测定活性炭的孔结构及其用作电极材料的电化学性能,并与日本商业化超级电容器用活性炭在结构及性能方面进行对比分析。结果表明,在碱炭比为3,微波活化时间为20min的条件下,可制备出比表面积达2593m2/g、总孔容达1.685cm3/g、孔径主要分布在0.5～10nm之间、中孔率达67.3%、平均孔径为2.61nm的优质活性炭。该活性炭用作超级电容器电极材料在3mol/L KOH电解液中具有优异的电化学性能,电流密度由50mA/g提高到10A/g时,其比电容由346F/g降低到273F/g,显示出良好的功率特性,经1000次循环后,比电容保持率为93.2%。与商业活性炭相比,微波法活性炭的性能更加优良。     

废茶叶基活性炭的制备及其电化学性能研究

以废茶叶的炭化料为前驱体,KOH为活化剂(碱炭比1∶1、2∶1、3∶1),在800℃下活化1h制备双电层电容器用活性炭电极材料。利用扫描电镜、低温N2吸附对活性炭的形貌、孔结构进行表征,采用恒流充放电、循环伏安和交流阻抗等测试方法评价其在3mol/L KOH电解液中的电化学性能。结果表明,3种活性炭比表面积、总孔容和中孔率最高分别达1 900m2/g、0.919 4cm3/g和35.7%;3种活性炭电极材料在0.055 6 A/g电流密度下的比电容分别为202F/g、255F/g、194F/g,电流密度增加到2.780A/g时,电容保持率分别为84.2%、67.1%、86.6%;等效串联电阻仅为0.10~0.12Ω;在碱碳比为2∶1时制备的活性炭电极材料在2.363A/g下比电容为148F/g,经1 000次循环充放电后,其质量比电容为147.7F/g,电容保持率高达99.3%。     

ZnCl2活化茄子秸秆制备活性炭及表征

以茄子秸秆为原料、ZnCl2为活化剂制备活性炭。通过正交实验方法确定了制备活性炭的最佳工艺条件,采用低温氮气吸附、BET、Langmuir和BJH理论对其孔结构进行了表征,利用红外光谱分析样品的表面官能团,扫描电镜观察表面形貌。结果表明以茄杆活性炭的最佳工艺条件:浸渍比为2,浸渍时间为8h,活化温度为550℃,活化时间为60min,所得的活性炭的碘吸附值为1270.06mg/g,亚甲基蓝吸附值为17.4mL/g;BET和Langmuir比表面积分别为1649.615和1851.649m2/g,吸附总孔容为0.488cm3/g,吸附平均孔径为2.241nm。     

废弃杏核壳制备高碘值活性炭及表征研究

以杏核壳为原材料,采用磷酸浸渍两步活化法制备活性炭。以碘值为响应值,经过正交优化试验确定高碘值活性炭制备的最优工艺组合为250℃炭化0.5h、60%磷酸 浸渍、900℃活化1h,样品碘值 高达1354mg/g。对制备的高碘值活性炭进行氮气等温吸脱附实验,结果表明所制备的活性炭属于微孔型,微孔总孔 体 积0.4201cm3/g,Langmuir比 表 面 积 高 达1339m2/g。利用扫描电镜和X射线衍射仪对杏壳活性炭的表面形态及活性炭晶体结构进行观察分析。     

柑橘皮中孔活性炭的制备及性能表征

以柑橘皮为原料,以氯化锌为活化剂,采用一步炭化法制备了中孔活性炭.研究了浸渍比、炭化温度及保温时间对孔结构的影响,通过BET、D-R方程、BJH方程及Kelvin理论表征了活性炭的孔结构,采用红外光谱分析样品的表面官能团,透射电镜观察微观形貌.柑橘皮中孔活性炭的适宜制备条件为:活化剂漫渍比3:1,炭化温度550℃,保温时间1h;所得活性炭中孔容积1.438cm3/g,中孔率占68.5%,BET比表面积为1476m2/g;该活性炭孔径分布集中,平均孔径3.88nm.利用中孔活性炭吸附垃圾渗滤液生化尾水,UV254值和TOC去除率分别为94.7%、66.4%.3DEEM证明该活性炭对DOM中的类富里酸具有良好的吸附性能,紫外区类和可见区类富里酸荧光强度分别降低49.1%、81.6%.     

微波热裂解-KOH活化制备杏壳活性炭及其对甲基橙的吸附性能

以陇东地区生物质废弃物杏壳为原料,采用微波热裂解-KOH活化联合法制备活性炭,研究了微波功率和时间,活化过程中KOH溶液的浓度、用量、浸渍时间、加热活化温度和时间对活性炭吸附性能的影响;以甲基橙为染料模拟印染废水,研究了甲基橙初始浓度、振荡吸附时间和活性炭用量对吸附效果的影响。结果表明:微波功率800W,热裂解30min,生物炭的收率为56%;KOH溶液的浓度为25%,碱/炭为2.5∶1,活化温度800℃,加热活化1.5h,所制备活性炭的碘吸附值为1332mg/g,比表面积为1223m2/g,总孔体积为0.68cm3/g,活性炭的得率为32.7%;甲基橙浓度为250mg/g,振荡吸附240min,活性炭用量为每100mL甲基橙溶液0.15g时,甲基橙去除率高达99.78%;吸附过程符合准二级动力学方程。     

聚丙烯腈基中孔碳的无机模板法制备和结构

采用模板法可制备孔径分布窄、中孔率和比表面积高的中孔碳。本文采用纳米氧化硅静电吸附十六烷基三甲基溴化铵(CTAB)及乳液聚合制备不同纳米氧化硅含量的聚丙烯腈/纳米氧化硅复合粒子,进一步通过高温碳化和氢氟酸刻蚀得到高纯度的中孔碳。发现当纳米氧化硅添加量不超过单体质量的50%时,纳米氧化硅主要以被聚合物包覆的形式存在,所制备的中孔碳的比表面积均大于800m2/g,孔径在5～10nm之间;随着纳米氧化硅/单体质量比从30%增加到60%,所制得的中孔碳的总孔容从1.111cm3/g增加至1.949cm3/g,中孔率从66.0%增至82.4%。结合中孔碳的形貌分析,认为纳米氧化硅的模板作用是形成中孔的主要因素。     

柚子皮基层次孔炭的制备及电化学性能

以柚子皮水热炭为前驱体,KOH为活化剂,800℃活化制备层次孔炭电极材料。采用扫描电子显微镜(SEM)、N2吸附法对活性炭的表面形貌和孔结构进行了表征,并评价了其在无机电解液体系(3mol/L KOH)中的电化学性能。结果表明,碱碳比为1∶1时制备的活性炭呈蜂窝状结构,其比表面积、总孔容分别达到1421 m2/g和0.7626cm3/g,相应的电极材料具有典型的双电层电容特性,质量比电容和体积比电容分别达到226F/g和250F/cm3(电极片密度为1.1g/cm3),1000次循环之后电容保持率达到91.45%。与柚子皮直接活化制备的电极材料相比,质量比电容和体积比电容分别增加了31.40%和37.36%。     

Leaching copper from shredded particles of waste printed circuit boards

Leaching copper from shredded particles of waste printed circuit boards (PCBs) was carried out in sulfuric acid solution using hydrogen peroxide as an oxidant at room temperature. The influence of system variables on copper recovery by leaching was investigated, such as sulfuric concentration, amount of hydrogen peroxide addition, waste PBCs particle size, presence of cupric ion, temperature and time. The results shown that the optimum addition amount was 100mL 15 (wt%) sulfuric acid solution and 10 mL of 30% hydrogen peroxide for leaching 10 g waste PCBs powder with a solid/liquid ratio of 1/10 for 3h at room temperature (～23 °C). Moreover leaching temperature and initial copper ion concentration had insignificant effect on the leaching recovery of copper. The effect of different particle size of shredded waste PCBs on leaching of copper was investigated under the optimum leaching condition. The results revealed that shredding pieces of waste PCBs smaller than 1mm was efficient and suitable for copper leaching. Then the leaching solution was concentrated to crystallize CuSO(4)·5H(2)O, and crystal liquor was reused for the next cycles.     

甘蔗渣基氧化石墨烯制备条件的响应曲面法优化设计

以甘蔗渣为基质采用改进Hummers法制备氧化石墨烯(GO),利用响应曲面法优化实验设计对甘蔗渣为基质的GO制备条件进行优化。选取碳粉用量、高锰酸钾用量、浓硫酸用量和超声时间作为4个变量因素,以制备的GO的红外特征吸收峰强度为响应值,利用Design-Expert软件进行数据分析,确定甘蔗渣基GO的最佳条件为:碳粉用量3.39g、高锰酸钾用量4.21g、浓硫酸用量20.68mL、超声时间7.75h。扫描电子显微镜和傅里叶变换红外光谱仪分析表明,在最佳条件下制备的GO具有明显的片层结构,特征峰出现在1500cm^-1、2300cm^-1、2400cm^-1和3500cm^-1处。     

酸激发提高钢渣、矿渣复合粉水硬活性的研究

叙述了分别采用硫酸和醋酸对钢渣、矿渣复合渣粉进行活性激发的试验研究结果。试验发现,经酸激发后的水泥复合渣体系的标准稠度用水量增加了约16￣17 mL左右;用硫酸激发该体系时,不同的酸浓度下初凝和终凝时间均得以延长,而醋酸激发导致凝结时间变化规律较为复杂。多数情况下,经酸激发可提高体系在各龄期的强度。考察复合渣粉活性指数可知,采用0.01￣0.1 mol/L硫酸激发复合渣粉可满足S95级矿渣粉标准对该项指标的要求。综合各龄期的测试结果,将激发用酸的浓度控制在0.1 mol/L左右是合适的。     

浓硫酸中304不锈钢焊接接头腐蚀行为的电化学研究

为了给应用于浓硫酸工业生产的304不锈钢管道的防护提供指导,采用电化学阻抗谱法与动电位扫描法研究了304不锈钢焊接接头各个区域在质量分数为98%的浓硫酸中不同温度下的腐蚀行为。结果表明:304不锈钢焊接接头在浓硫酸中的腐蚀形式以点蚀为主。在相同条件的浓硫酸介质中,焊接接头各区域耐蚀性优劣依次为:基材、焊缝、热影响区,焊接过程对不锈钢的腐蚀起到促进作用。随着硫酸介质温度的逐渐升高,基材的钝化膜比较稳定,而焊缝与热影响区的钝化膜会发生破裂;并且各区域的自腐蚀电流与腐蚀速率会逐渐增大,耐腐蚀性逐渐下降。     

双分子层液膜法制备纤维素水基泡沫及其稳定性的研究

目的 解决纤维素基泡沫制备过程烦琐、湿泡沫的稳定性差的问题。方法 通过单因素试验,考察了十四醇（TDA）、阿拉伯胶（GAC）质量浓度对双膜气泡的稳定性的影响,在此基础上,采用泡沫成形法制备纤维素水基湿泡沫,通过探究合适的十二烷基硫酸钠（SDS）质量浓度、蔗渣原纤浆质量浓度和搅拌速率进一步提高纤维素水基湿泡沫的稳定性。结果 TDA和GAC质量浓度分别为0.015 g/mL和0.010g/mL时是制备双膜气泡的最佳条件。当SDS质量浓度为0.015g/mL、蔗渣原纤浆（BF）质量分数为1.8%、搅拌速率为2 000 r/min时,纤维素水基湿泡沫稳定性达到最佳。结论 构建了稳定的纤维素水基泡沫,为纤维素基泡沫提供了一种简单、可行的方法。     

硫酸盐半光亮电镀锡工艺优化

为了淘汰半光亮电镀锡标准溶液中存在的潜在性致癌物质β-萘酚,通过正交试验和赫尔槽试验确定了一种新型的硫酸盐半光亮电镀锡工艺,采用碘量法、远近阴极法、称重法、阴极极化曲线、湿润法和扫描电镜(SEM)对最佳镀液及镀层性能进行了测试。结果表明:最佳工艺为0.05 g/L苄叉丙酮,1.5 m L/L NP-10,0.10 g/L烟酸,0.50 g/L LF-21,1.00 g/L明胶,20.00~40.00 g/L硫酸亚锡,80.0~120.0 m L/L硫酸,时间为35 min,温度为2030℃,电流密度为12 A/dm~2;本镀液稳定周期长,2526℃下放置2个月以上不变质,且分散能力高达88%94%,电流效率接近100%;锡镀层晶粒细小、致密,结合力和可焊性均达到了国家标准。     

Regeneration of granular activated carbon saturated with acetone and isopropyl alcohol via a recirculation process under H2O2/UV oxidation

This study examines a water-based system, coupling an adsorber and a photoreactor, for regeneration of granular activated carbon (GAC) saturated with acetone and isopropyl alcohol (IPA). Through water recirculation the regeneration reaction was operated in both intermittent and continuous ultraviolet illumination modes. With a periodic dosage of hydrogen peroxide not only was regeneration efficient but it was also catalyzed by GAC in the adsorber. The concentrations of acetone, solution chemical oxygen demand (COD), pH and organic residues on GAC surfaces were measured during regenerations. Both pH and solution COD were found to correlate with regeneration completion as measured by organic residue on GAC surfaces in four regeneration cycles with acetone. Solution pH decreased to the acidic values and then returned to near its original value when organic residues were 0.085-0.255 mg/g GAC, that is, destruction efficiency of adsorbed acetone on the GAC surface was more than 99%. Likewise, solution COD became low (<100 mg/l) at regeneration completion. The pH variation pattern was then applied to another four cycles of regeneration with IPA, and successfully reflected the timing of complete regeneration. The final levels of organic residue on GAC surfaces were between 0.135 and 0.310 mg/g GAC in each of four regeneration cycles, each of which had been stopped based on the measurements of pH and solution COD. Furthermore, nearly the same batch of GAC could be repeatedly used with little changes in physicochemical properties in each of eight cycles: adsorptive capacities were 95+/-7 mg acetone/g GAC and 87+/-3 mg IPA/g GAC, and breakthrough time was 0.86+/-0.05 for acetone and 0.78+/-0.03 h for IPA. An economic assessment of the system showed that the operating cost was about 0.04 USD for treating every gram of acetone in the air.     

废弃聚苯乙烯制备活性炭的初步研究

废弃的聚苯乙烯经过炭化,活化后成为活性炭,优化工艺条件下得到的活性炭碘吸附值为1765mg/g,虽然最终的活性炭产率并不高,但也为处理废弃的聚苯乙烯提出了一种新的解决途径.     

Preparation and electrochemical properties of sodium-reduced graphene oxide

Graphite oxide reduction is probably one of the best technique used to obtain large quantities of few-layer graphene. We developed a new method to produce reduced graphene oxide by using sodium metal as a reducing agent with subsequent dehydration in concentrated sulfuric acid. The resulting product was characterized using various analytical techniques with respect to the oxygen content and species of the residual oxygen-containing groups. The reduced graphene oxide prepared by this method was electrochemically tested as electrode in supercapacitors using two-electrode symmetric system and aqueous electrolyte. The product exhibits improved capacitance during cyclic voltammetry measurements. In comparison to parent graphite oxide specific capacity increased from 0.88 to 28 F/g after 10 cycles at scan rate 20 mV/s and dropped to 19.44 F/g after 100 cycles while at scan rate 5 mV/s specific capacity 46.41 F/g was recorded after first cycle and 39.90 F/g after 50 cycles.     

Consequence of chitosan treating on the adsorption of humic acid by granular activated carbon

In this work, equilibrium and kinetic adsorption of humic acid (HA) onto chitosan treated granular activated carbon (MGAC) has been investigated and compared to the granular activated carbon (GAC). The adsorption equilibrium data showed that adsorption behaviour of HA could be described reasonably well by Langmuir adsorption isotherm for GAC and Freundlich adsorption isotherm for MGAC. It was shown that pre-adsorption of chitosan onto the surface of GAC improved the adsorption capacity of HA changing the predominant adsorption mechanism. Monolayer capacities for the adsorption of HA onto GAC and MGAC were calculated 55.8 mg/g and 71.4 mg/g, respectively. Kinetic studies showed that film diffusion and intra-particle diffusion were simultaneously operating during the adsorption process for MGAC.