改性壳聚糖的制备及对Cu2+Pb2+的吸附研究

用巯基乙酸作为巯基化剂,对壳聚糖进行改性,选择了巯基化的条件.实验表明,在浓度为188mg/L的铜溶液中,CTS-SH的最大吸附率达90.3%以上,吸附容量为27.76mg/g,在浓度为203mg/L的铅溶液中,对铅的最大吸附率达到99%以上,在浓度为1.015g/L的铅溶液中,最大吸附率达95.5%.此时的吸附容量为97.4mg/g,吸附容量大于147.2mg/g时的吸附率为36.3%.经XRD及EMS图片的分析,可以看出,改性壳聚糖在吸附前后,结构发生了改变.     

希夫碱型木质素基吸附材料的制备及其对Pb~(2+)吸附性能研究

以乙酸木质素为原料,通过曼尼希胺化反应和希夫碱反应制备希夫碱型木质素基离子吸附材料(SLA),利用红外光谱、核磁共振氢谱和元素分析等手段对SLA的结构进行表征。考察了溶液pH值、吸附剂用量和离子溶液初始浓度等因素对SLA吸附性能的影响。结果表明,在pH=5.0、吸附剂用量2.0g/L、Pb~(2+)溶液浓度200mg/L条件下,SLA对Pb~(2+)具有较高的吸附量(65.45mg/g)和良好的吸附选择性。研究结果表明,SLA对Pb~(2+)的等温吸附过程符合Freundlich等温吸附模型,存在非均匀多层吸附现象;SLA对Pb~(2+)的吸附动力学过程符合准二级吸附动力学模型,表明SLA对Pb~(2+)的吸附作用主要为化学吸附。     

啤酒酵母废菌体吸附Pd2+的物理化学特性

以啤酒酿造厂的啤酒酵母废菌体为生物吸附剂,研究死的啤酒酵母菌体从PdCl₂溶液中吸附Pd²⁺的物理化学特性.结果表明,该菌体吸附Pd²⁺受吸附时间、溶液pH值、菌体浓度和Pd²⁺起始浓度等因素的影响.菌体吸附Pd²⁺是个快速的过程,吸附45min时吸附量达最大,但在最初的3min内,吸附量可达到最大吸附量的92%.在5～60℃范围内,吸附作用不受温度影响.吸附作用的最适pH值为3.5.在Pd²⁺起始质量浓度为30～300mg/L范围内和菌体质量浓度为2g/L的条件下,菌体对Pd²⁺的吸附作用符合Langmuir和Freundlich等温吸附模型.在pH=3.5,Pd²⁺与菌体质量比为0.2和30℃条件下吸附60min,吸附量达94.5mg/g.从废钯催化剂处理液回收钯,吸附量为32.2mg/g.XPS分析表明,该菌体能吸附水溶液中的Pd²⁺.TEM结果表明,在无外加电子供体时,死的啤酒酵母废菌体能够吸附和还原溶液中的Pd²⁺成Pd⁰微粒,Pd⁰微粒可进一步形成有一定形状的钯晶粒;该菌体还能使吸附在γ-Al₂O₃上的Pd²⁺还原成Pd⁰.     

交联黄原酸壳聚糖对铅离子的吸附研究

以壳聚糖为原料,通过交联和黄原酸化反应制备出交联黄原酸壳聚糖,采用FT-IR和XRD表征了其结构,并探讨壳聚糖及交联黄原酸壳聚糖对Pb2+的吸附性能。研究了初始溶液pH值、温度以及吸附时间等因素对Pb2+吸附量的影响。结果表明,在Pb2+起始浓度0.01 M,起始溶液pH=5,室温25℃吸附2h条件下,壳聚糖和交联黄原酸壳聚糖对铅离子的吸附量分别为126.8 mg/g和238.9 mg/g,交联黄原酸壳聚糖吸附能力为壳聚糖的1.89倍。     

乙二胺硅胶材料对铜和锌离子的动态吸附

合成了胺基含量为1.35 mmol/g的乙二胺硅胶材料(EDA/SiO2),研究了EDA/SiO2对Cu2+和Zn2+的动态吸附及动态竞争吸附。结果表明,铜溶液流量和初始浓度对材料动态吸附性能有显著影响,随着溶液初始浓度的增大、流速的加快,穿透时间明显缩短。动态吸附实验结果符合Thomas模型,计算结果显示,铜溶液初始浓度由1.99 mmol/L增大至10.00 mmol/L时,模型平衡吸附容量q0从0.272 mmol/g增大至0.476 mmol/g,影响显著;流量对q0影响不显著。溶液流量和初始浓度对吸附速率常数kTh均有影响,随溶液流量增大、初始浓度的降低,速率常数值增大。在单一体系中,EDA/SiO2对Cu2+和Zn2+的工作吸附量分别为0.340和0.127 mmol/g,混合体系的吸附量均小于单一体系中的吸附量,并且对Zn2+的吸附量下降显著,表明EDA/SiO2对Cu2+的吸附能力强于Zn2+。6次循环实验表明,盐酸和氨水可对EDA/SiO2材料实现再生,再生后材料对铜的吸附容量和穿透时间的下降幅度不大,可重复使用。     

磁性海藻酸钠三互穿网络水凝胶对亚甲基蓝的吸附

以海藻酸钠为水凝胶骨架材料,以羧甲基纤维素钠（CMC）和质子化壳聚糖（CTS）为强度增强材料,制备磁性水凝胶球吸附剂Fe3O4@SA@CMC@CTS,研究其对水溶液中亚甲基蓝（MB）的吸附特性,考察吸附时间、MB 初始浓度、离子强度、吸附剂加入量等对凝胶球吸附性能的影响;引入吸附动力学和热力学模型对吸附过程进行分析,并采用傅里叶红外光谱（FT-IR）、Zeta 电位、磁滞回线和X射线光电子能谱（XPS）对凝胶球特征及吸附机理进行综合分析。结果表明：在25 ℃、质量浓度为700 mg/L的MB溶液、凝胶球用量为0.2 g/L的条件下,平衡吸附量为2143.0 mg/g;700 mg/L的MB溶液最佳凝胶球投加量为 0.4 g/L,重复利用5次后,吸附量仍高达1228.4 mg/g。动力学拟合显示该吸附过程更符合准一级动力学模型,等温拟合表明Freundlich 吸附等温方程可以更好地描述该吸附过程。     

中孔分子筛SBA-15-NH2 分离富集火焰原子吸收光谱法测定烟花中痕量钯的研究与应用

建立了中孔分子筛SBA-15-NH2分离富集火焰原子吸收光谱法测定痕量钯的新方法,探讨了中孔分子筛SBA-15-NH2材料吸附钯的原理和最佳条件.在pH 3.0、温度为(15±1) ℃的条件下,钯可被该材料定量吸附,其吸附容量为1.21 mg/g.吸附的钯用饱和硫脲溶液洗脱,并用火焰原子吸收法测定洗脱的钯.该方法测定钯的检出限为0.59 μg/L(3σ,n=11),线性范围为0.002 ～1.2 mg/L,加标回收率为98% ～107%.对0.05 mg/L的Pd2+溶液平行测定7次,RSD为2.24%.方法用于烟花中痕量钯的测定,结果满意.     

壳聚糖-叶酸复合凝胶的制备及Pb2+吸附性能研究

叶酸(FA)通过离子交联壳聚糖构筑了壳聚糖-叶酸水凝胶(CS-FA-HG),利用红外光谱、紫外-可见光谱、电子扫描显微镜等对其结构进行表征,并考察了CS-FA-HG对Pb²⁺的吸附性能。实验结果表明,FA、壳聚糖醋酸盐(CS-Ac)浓度均为35 mg/mL,Na₂CO₃溶液的质量分数为5.0%时,FA钠盐通过静电作用离子交联CS-Ac,形成CS-FA-HG,微观呈枝状纤维结构;在pH 5.0,吸附温度30℃的条件下,80 mg干CS-FA-HG在50 mL初始浓度15 mg/L的Pb²⁺溶液中,对Pb²⁺的吸附量为8.14 mg/g;吸附符合二级动力学方程和Langmuir吸附等温式。CS-FA-HG制备方法简单,绿色环保,无二次污染,在重金属离子吸附方面有潜在应用。     

反应介质对ZnO粉体材料结构、吸附及光催化性能的影响

以Zn(NO_3)_2·6H_2O和Na OH为原料,分别以无机溶剂(水)和有机溶剂(无水乙醇和乙酰丙酮的混合物)为反应介质,采用无机相碱沉淀法和有机相溶胶法,制备了两种ZnO粉体材料样品ZnO-1和ZnO-2。用X-射线衍射和扫描电镜对所制备的材料进行了结构与形貌表征,发现不同制备方法所得样品均为六方晶系纤锌矿结构,但材料的形貌有显著差异:无机相碱沉淀法制备的ZnO-1为鹅卵石状晶体,有机相溶胶法制备的ZnO-2为棒状晶体。测定了两种ZnO粉体材料对水溶液中甲基橙的吸附等温线,结果表明,ZnO-2对甲基橙的最大吸附容量达到38.9mg/g,而ZnO-1为28.8mg/g。测试了材料的光催化性能,结果表明,当甲基橙溶液初始浓度为20mg/L、ZnO样品的投加量为1g/L时,经300W高压汞灯照射3h后,ZnO-2棒状晶体对甲基橙溶液的降解率可达78.4%,所制备的材料重复使用4次均保持较高的催化活性。     

季铵盐型螯合树脂的合成及其对铅离子的吸附研究

合成了一种含有季铵盐结构的希夫碱型螯合树脂(CPS-DMA-S-HCTA),研究了其对Pb(II)离子的吸附和脱附行为.树脂红外光谱分析和元素分析结果表明,成功合成了CPS-DMA-S-HCTA螯合树脂;树脂的热分析结果表明,CPS-DMA-S-HCTA树脂的初始分解温度为205℃,具有良好的热稳定性;静态实验结果表明,在研究的浓度范围内,吸附平衡数据符合Freundlich等温吸附方程,且吸附为放热、混乱度减小的自发过程,吸附过程以化学吸附为主,298 K,Pb(Ⅱ)溶液的初始浓度为600 mg/L时,适宜的吸附pH为5~6,平衡吸附量为96.1 mg/g,吸附达到平衡的时间约为10 min.采用1.5 mol/L的硝酸溶液作脱附剂,脱附率可达98%以上,解吸速率快,10 min左右流出液中重金属离子的浓度几乎为0 mg/L.经过10次吸附-解吸-吸附研究表明,树脂可重复使用性强.     

In situ anchor of Na2Ti3O7 in nitrogen-rich carbon hollow red blood cell-like structure as a 0D-3D hierarchical electrode material for efficient electrochemical desalination

Reasonable design of the structure and complementary compounding of electrode materials is helpful to enhance capacitive deionization (CDI) performance. Herein, a novel 0D–3D hierarchical electrode material containing Na₂Ti₃O₇ nanoparticles anchored at hollow red blood cell (HRBC)-like nitrogen-rich carbon (HRBC-NTO/N-C-60) was prepared via selective protection, pyrolysis, and alkalization. Specifically, a HRBC-like NH₂-MIL-125-based material (HRBC-MOF-60) was first constructed by a selective protection approach of tannic acid (TN), which addresses the shortcomings of using sacrificial templates or corrosive agents. Afterwards, HRBC-NTO/N-C-60 was obtained in situ by annealing and alkalization of HRBC-MOF-60. The nitrogen-rich carbon with a HRBC-like structure has the ability to rapidly transport electrons, and its porous structure enables remarkable charge transfer. Benefiting from the grafted 3D N-doped porous carbon with a HRBC-like structure, well-dispersed 0D Na₂Ti₃O₇ nanoparticles, and satisfactory bonding effects, HRBC-NTO/N-C-60 exhibited high specific capacitance and fast ionic and electronic diffusion kinetics. Moreover, HRBC-NTO/N-C-60 was well-suited for desalination by functioning as a cathode material for capacitive deionization (CDI), and delivering a high desalination capacity of 66.8 mg g⁻¹ in 200 mg L⁻¹ NaCl solution at 1.4 V. This work introduces an excellent high-performance candidate for electrochemical deionization as well as affording afflatus for accurately inventing OD-3D hierarchical materials with hollow structures.

Hollow red cell-like Na₂Ti₃O₇/nitrogen-doped carbon are synthesized by a template-self strategy.     

A Polyoxometalate-Based Binder-Free Capacitive Deionization Electrode for Highly Efficient Sea Water Desalination

Capacitive deionization is a promising technique in sea water desalination. Compared with common electrodes, mixed capacitive-deionization electrodes exhibit better performance in sea water desalination because they integrate pseudocapacitance and electric double-layer capacitance in one system. Herein, a 3D binder-free mixed capacitive-deionization electrode was fabricated by direct electrodeposition of SiW₁₂O₄₀⁴⁻ and polyaniline on a 3D exfoliated graphite carrier. In this electrode, SiW₁₂O₄₀⁴⁻/polyaniline composite particles with a size of about 100–120 nm are dispersed homogenously on the 3D exfoliated graphite carrier. Its specific capacitance reaches 352 F g⁻¹ at 1 A g⁻¹. With increasing current from 1 to 20 A g⁻¹, the specific capacitance only decays by 32 %. When employed in sea water desalination, the performance of this mixed capacitive-deionization electrode is also excellent. At 1.2 V, the salt adsorption capacity of this mixed electrode reaches 23.1 mg g⁻¹ with a salt adsorption rate of 1.38 mg g⁻¹ min⁻¹ in 500 mg L⁻¹ NaCl. The performance of this electrode is well retained after 30 cycles. The excellent sea water desalination performance originates from the synergistic effect between SiW₁₂O₄₀⁴⁻ and polyaniline. This work has developed polyoxometalate as a new material for capacitive-deionization electrodes.     

空心海胆状二氧化锰的制备及其在超级电容器中的应用

采用简单的一步水热法制备了空心海胆状二氧化锰,无需任何模板剂和表面活性剂。该材料具有3D的纳米结构,结构稳定,并由单个的二氧化锰空心管自组装而成。该纳米材料的特殊结构为其提供了高的比电容。在1mol·L-1硫酸钠电解液中,扫速为1mV·s-1的条件下,该材料的比电容值为254.6F·g-1。在电流密度为1.0A·g-1的条件下,充放电循环1000次后比电容值仍保持为初始值的97.5%。表明该材料具有良好的电容性能和稳定性,其具备用作高性能超级电容器的电极材料的潜能。     

空心海胆状二氧化锰的制备及其在超级电容器中的应用

采用简单的一步水热法制备了空心海胆状二氧化锰,无需任何模板剂和表面活性剂。该材料具有3D的纳米结构,结构稳定,并由单个的二氧化锰空心管自组装而成。该纳米材料的特殊结构为其提供了高的比电容。在1mol·L^-1硫酸钠电解液中,扫速为1mV·s^-1的条件下,该材料的比电容值为254.6F·g^-1。在电流密度为1.0A·g^-1的条件下,充放电循环1000次后比电容值仍保持为初始值的97.5%。表明该材料具有良好的电容性能和稳定性,其具备用作高性能超级电容器的电极材料的潜能。     

Preparation of activated carbon from waste Camellia oleifera shell for supercapacitor application

The cost-effective activated carbons derived from waste Camellia oleifera shell (COS) by ZnCl₂ activation method are investigated as the active electrode material in electric double-layer capacitors (EDLCs) for the first time. The activation temperature and ZnCl₂/COS impregnation ratio are two key factors affecting the surface area and pore structure of the prepared activated carbons, which accordingly affect their capacitive performances. Electrochemical investigations indicate that the activated carbon (AC-3-600) obtained at the activation temperature of 600 °C and impregnation ratio of 3 shows the maximum specific capacitance of 374 and 266 F?g^?1 in 1 mol L^?1 H₂SO₄ and 6 mol L^?1 KOH electrolytes at 0.2 A g^?1, respectively. The high capacitance of the AC-3-600 is attributed to its high surface area (1,935 m² g^?1), high total pore volume (1.02 cm³ g^?1), and especially the large percentage of micropores (735 m² g^?1). Meanwhile, the activated carbon presents good cycle stability in both acid and alkaline electrolytes during 5,000 cycles at a fair current density of 4 A g^?1. So, we had reasons to believe that the activated carbons from waste COS by ZnCl₂ activation might be one of the innovative carbon electrode materials for EDLCs application.     

由微孔棒状羟基磷灰石为模板合成的新型层次孔炭材料的电化学电容性能

电化学电容器已经成为极具潜力的可满足高功率需求的储能系统器件. 多孔炭具有大比表面积、高导电性、化学惰性、廉价及可调孔结构等优势, 因此成为电化学电容器最为常用的电极材料. 本文报道由微孔棒状羟基磷灰石为模板及蔗糖为碳源合成的新型具有层次孔道结构的孔炭材料的电化学电容器的性能. 采用X射线衍射分析仪、扫描电子显微镜、透射电子显微镜、X射线光电子能谱及BET表面分析仪表征了合成的多孔炭的形貌及表面特性. 采用循环伏安法、交流阻抗图谱分析及恒流充放电评价多孔炭材料在1 mol·L^-1硫酸中的电化学电容性能. 多孔炭具有高的比表面积(719.7 m²·g^-1)和大的孔容(1.32 cm³·g^-1), 其无序的孔道由任意分布的微孔、坍塌的中孔及类模板形状的相互交织的棒状中孔组成. 随着炭化温度的增加, 微孔及棒状中孔的密度随之降低, 在炭化温度高达900℃时, 孔径分布图上出现了三个峰. 正是由于这些特殊的结构特征, 由900℃炭化得到的多孔炭制成的电极展示出很好的电化学电容性能.     

半晶化双螺旋介孔MnO2的合成和电化学性质

Mesoporous silica KIT-6 has novel three-dimensional gyroidal channel structure, space group of 1a-3d, and ordered tunable pores up to 10 nm. In this paper, such mesostructured silica was employed as hard template to prepare semicrystalline gyroidal mesoporous MnO2. The structure was investigated by XRD, TEM and HRTEM, and found to be of high quality 1a-3d symmetry, in good accordance with the template structure. The material has a BET surface of 118 m2·g^-1 and pore volume of 0.35 cm3·g^- 1 after eliminating template. Mesoporous MnO2 has shown good electrochemical property as supercapacitor material in 1 mol·L^-1 Na2SO4 and 1 mol·L^-1 LiClO4 solutions, but interesting pseudocapacitance behavior was observed in the case of 6 mol·L^-1 KOH. It was found that mesoporous MnO2 performed stable reversible electrochemical behavior with capacitance of 220 F·g^-1 in a potential range of -0.1-0.55 V vs. Hg/HgO in alkaline solution, demonstrating that it is a promising novel electrode material for the fabrication of electrochemical capacitors.     

Innovative approach to treating waste waters by a membrane capacitive deionisation system

The application of membrane capacitive deionisation was investigated for treating model water samples and real waste waters from the textile industry. For the pre-treatment of waste waters, nanofiltration was integrated in order to prevent scaling and fouling of membranes and electrodes during membrane capacitive deionisation. Different conditions were applied when treating water samples with membrane capacitive deionisation with the aim of optimising conditions for high desalination efficiency and, consequently, for conductivity reduction. The conductivity of waste waters with high salt concentrations was reduced to the required value, below 1.5 mS cm^?1. The desalination rates achieved as much as 95 %, depending on the initial conductivity and the different ions present in the water samples. In addition, chemometric characterisation of the samples was performed in order to determine the existence of significant correlations between the monitored parameters: the presence of various ions (Na⁺, K⁺, Ca²⁺, Mg²⁺, Cl^?, Br^?, F^?, SO₄^2?, NO₃^?, desalination and water recovery, the duration of each phase and the flow of the solution during each phase. A model for desalination rate prediction was designed using multiple linear regression. It was established that the model values accorded well with the experimental values — the differences between model and experimental values were less than 1 %.     

一种高容量的层状Co-MOF基超级电容器电极材料

通过简单的溶剂热反应合成了一种钴基层状MOF（[Co（4,4''-bpy）（tfbdc）（H₂O）₂],Co-BTH,4,4''-bpy=4,4''-联吡啶,H₂tfbdc=四氟对苯二甲酸）,并考察了其作为超级电容器电极材料的性能。研究结果表明：Co-BTH电极具有良好的赝电容性能,包含高比电容和较好的倍率性能。在1 A·g^-1电流密度下和1 mol·L^-1 KOH溶液中,其比电容最大可达2 316 F·g^-1。在2 A·g^-1的电流密度下,循环1 000次后,电极的比电容仍然还有847 F·g^-1。良好的赝电容性能与Co-BTH的层状结构和小尺寸的纳米片有关。     

SnO2 /MWCNTs纳米复合材料的低热固相制备及其超电容特性研究

采用十二烷基三甲基溴化铵(DTAB)辅助固相法制备SnO2/MWCNTs纳米复合材料,X射线衍射(XRD)、透射电镜(TEM)测试表明,SnO2纳米颗粒均匀包裹在MWCNTs表面.循环伏安和恒流充放电测试表明,与SnO2颗粒和纯MWCNTs相比,SnO2/MWCNTs纳米复合材料在1.0 mol·L-1 Na2SO4电解液中的电化学电容性质得到明显改善.当SnO2质量分数为11%时,在电流密度0.2 A·g-1下,SnO2的电容值最大可达217.3 F·g-1.