固定化辣根过氧化物酶的电化学和电催化特性

用海藻酸钠(SA)将辣根过氧化物酶(HRP)固定到热裂解石墨电极表面,制备了HRP-SA膜修饰电极。研究发现包埋在SA膜中的辣根过氧化物酶可与电极直接传递电子,在缓冲溶液中可得到一对辣根过氧化物酶辅基血红素Fe(Ⅲ)/Fe(Ⅱ)电对的可逆氧化还原峰。其式电势随溶液pH值增加而负移,且呈线性关系,这说明辣根过氧化物酶的电子传递过程伴随有质子的转移。并考察了HRP-SA膜修饰电极对氧气、双氧水、一氧化氮的电催化性质。     

肌红蛋白/碳纳米管修饰电极的直接电化学研究

将肌红蛋白(Mb)通过静电作用吸附到碳纳米管(CNT)的表面,并研究了碳纳米管对肌红蛋白直接电子转移反应的促进作用。从循环伏安曲线可以看到一对良好的、几乎对称的氧化还原峰,这表明Mb在CNT表面可以进行有效和稳定的直接电子转移反应,进一步的实验结果显示,固定在CNT表面的Mb能保持其对H2O2和O2还原的生物电催化活性。     

血红蛋白在海藻酸钠膜中的电化学和类酶活性研究

用海藻酸钠(SA)将血红蛋白(Hb)固定到热裂解石墨电极表面,制备了Hb-SA膜修饰电极。包埋在SA膜中的Hb在磷酸盐缓冲溶液和乙醇混合溶液中与电极直接传递电子,得到一对对称的血红蛋白辅基血红素Fe(Ⅲ)/Fe(Ⅱ)电对的可逆氧化还原峰。其式电势随缓冲溶液pH值增加而负移,且呈线性关系,这说明血红蛋白的电子传递过程伴随有质子的转移。并考察了Hb-SA膜修饰电极在缓冲溶液和乙醇混合溶液中对氧气、双氧水、一氧化氮和六氯乙烷的电催化性质。     

PtPd合金的电化学制备及其对甲醇的电催化氧化

近年来,以液态醇类为燃料的直接醇类燃料电池极为常见,受到了相关工作人员的高度关注。主要从PtPd合金的制备及其对甲醇的电催化氧化性能入手,对实验结果进行分析。结合实际情况分析PtPd电极对甲醇的电化学氧化催化活性的影响,以期能更好地促进相关工作开展。     

碳化钼的制备及其电化学性能的研究

在电解水的过程中,使用金属铂作为电化学析氢的材料具有价格昂贵、稳定性差等缺点,造成电解水析氢的成本高,不能大规模生产.所以科研人员开始探索高效率且价格低廉的催化剂来提高电解水的析氢效率.碳化钼由于与金属铂具有相似的d能带电子密度状态,且碳化钼具有导电导热性能良好、稳定性高以及简单的合成方法等特点,由此被认为是最佳的可替...     

电催化氮还原合成氨MOF基催化剂研究进展

室温下电催化氮还原合成氨（nitrogen reduction reaction,NRR）因其较低的能耗而受到广泛关注。到目前为止,设计高效电催化剂以提高NRR性能是研究重点。其中,金属有机骨架（metal organic framework,MOF）及衍生材料因其独特的多孔结构和可控成分等优势促进了其在气体捕获、分离和催化中的应用。本文首先讨论NRR的反应机制,然后重点讨论MOF及衍生材料用作NRR电催化剂的研究进展,最后,对MOF基NRR电催化剂的设计策略、存在问题及NRR催化面临挑战进行了总结与展望。此外,文中指出：(1)自支撑MOF基电催化剂的合理设计对NRR性能有质的提升;(2)机器学习、DFT计算及原位测试技术的有效结合对NRR机理、催化剂的高效设计及筛选等具有重要指导意义。因此这些也将成为NRR催化未来研究趋势。     

新型环保材料膨胀石墨的电化学法制备及性能

以有机-无机混酸溶液为介质用电化学法制备了膨胀石墨，并用扫描电子显微镜(SEM)观察其表面形貌，膨胀后的石墨具有丰富的网络状结构，形成吸附油的储存空间。膨胀石墨对重油的吸附量随着膨胀容积的增大而增加，合适的电流密度、电解液浓度以及反应时间是制备高膨胀容积膨胀石墨的关键。     

合成方法对针状焦电化学性能的影响研究

针状焦是一种常见的碳材料,具有广泛的应用前景。本文通过综述目前合成针状焦的不同方法,探究不同合成方法对针状焦的电化学性能的影响。结果表明,采用化学气相沉积法合成的针状焦具有良好的电化学性能,表现出优秀的电催化活性和超级电容性能。因此,选择合适的合成方法是提高针状焦的电化学性能的有效途径。     

钯纳米粒子修饰电极对过氧化氢电催化性能研究

采用电位阶跃的方法沉积Pd纳米颗粒,在多壁碳纳米管修饰电极表面获得了分散性良好的Pd纳米粒子,然后采用循环伏安法对该修饰电极进行电化学研究。结果表明,该修饰电极对双氧水的还原具有较高的电催化活性,可用于对H2O2的检测,其检测下限为3.7×10-6 M（S/N=3）,检测的线性范围为8×10-6～5×10-3 M。制得的修饰电极对双氧水的催化还原具有灵敏度高、重现性好和灵敏度高等优点。     

电催化氧化法降解炼油二级出水CODCr的研究

以炼油厂二级出水回用为目的,研究了电催化氧化法降解炼油厂二级出水CODCr的方法。实验结果表明,电催化氧化法可在炼油厂二级出水回用中降解CODCr。当废水处理后ρ(CODCr)小于30mg/L时,处理每吨废水的电能消耗在1kW·h左右。CODCr的降解效果依赖于废水性质、电解时间、电极材料、电流密度、电极间距、电解槽结构、废水流量等因素。     

细胞色素c在马铃薯膳食纤维修饰电极上的直接电化学行为

用水蒸汽爆破和氧化法对马铃薯废渣(PR)进行处理制备马铃薯膳食纤维(PDF),并用红外光谱法、扫描电镜等方法对膳食纤维进行表征。结果表明,马铃薯渣中的半乳聚糖在蒸汽爆破下由长链断成短链,且由原来的块状变成片状、无规则的空间网层结构,断链的半乳糖醛基在氧化作用下生成羧基;所得到的PDF具有比表面积大、吸附位点多等特点。将马铃薯膳食纤维与聚乙烯醇(PVA)制备成水凝胶修饰到玻碳电极表面,研究细胞色素c(Cyt c)在该电极上的直接电化学,探讨了马铃薯膳食纤维与Cyt c间的相互作用,构建了新型过氧化氢生物传感器。用计时电流法测定过氧化氢的线性范围为8.0×10-6~2.4×10-4mol/L,检出限为4.0×10-6mol/L。     

SA-CMC固定反硝化细菌好氧反硝化性能探究

为扩大反硝化菌应用和抗逆性,以海藻酸钠(SA)和羧甲基纤维素钠(CMC)为载体、用CaCl2交联,联合包埋脱氮副球菌,制作反硝化菌剂,探究有氧条件下,菌剂的好氧反硝化性能.结果表明,有氧条件下,所得菌剂对硝态氮的还原能力显著高于游离态菌(总氮氧化物去除率分别为95.6％和9.6％).CMC含量升高能显著提高菌剂好氧反硝...     

固定化菌种降解丁二腈的研究

分别用海藻酸钠与聚乙烯醇为载体,对前期研究中获得的丁二腈高效降解菌进行包埋固定。研究了不同载体包埋固定的菌种对废水中丁二腈的降解效果。结果表明,采用海藻酸钠包埋固定的菌种在30℃,pH=6.5,摇床转速为250r/min的条件下,当菌的质量浓度为lg/L和2g/L时,丁二腈的降解率均达80%以上。     

Asymmetric Reduction of 3,5-Bistrifluoromethyl Acetophenone with NADH Regeneration by Immobilized Cells of Saccharomyces rhodotorula in Aqueous-Organic Solvent Biphasic System

Asymmetric reduction of 3,5-bistrifluoromethyl acetophenone to produce(S)-3,5-bistrifluoromethylphenyl ethanol was successfully carried out with sodium alginate immobilized Saccharomyces rhodotorula cells in an aqueous-organic solvent biphasic system.The possible influential factors were examined thoroughly according to their effects on conversion rate and e.e of the product.Organic solvents were rated by their biocompatibility and conversion potential.The immobilized cells [125 mg/mL in 20 mmol/L Tris-HCl ...     

Characterization and preparation of polyion complex composite membranes for the separation of methyl tert‐butyl ether/methanol mixtures

A series of polyion complex (PIC) composite membranes composed of sodium alginate (SA) polyanion and chitosan polycation were prepared by varying the ratio of concentration. The interaction between SA and chitosan was investigated by FTIR, SEM, and X‐ray analysis and was related to mechanical properties and the swelling phenomenon. The overall PIC composite membranes showed the following results: the total thickness of the coating layer was thicker than that of pure SA composite, and increased with increasing the concentration of chitosan solution during PIC formation. This result was attributed to the diffusion of chitosan molecules from the liquid solution into the SA matrix, and the incorporation with SA molecules. For the PIC membranes prepared with different concentrations of polymer solution, their structural differences could not be detected from IR spectra but their morphological differences could be noticeably found from SEM. Furthermore, the amorphousness of PIC membranes and their elongation properties at break increased significantly as a function of polymer contents, whereas the tensile modulus decreased because of the physical transition effect. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 714–725, 2002     

血红蛋白的电化学和电分析化学研究进展

血红蛋白是一种重要的生物大分子,在生命活动中起着重要作用,有关它的电化学和电子转移过程的研究对于揭示生命过程的本质有着重要意义。对血红蛋白在裸电极和化学修饰电极上的电化学行为和电催化机理进行了综述,并介绍了可用于检测血红蛋白的电化学分析方法及应用。     

Teaching and Learning Electrochemistry

Numerous conceptual difficulties and misconceptions have been reported in the science and chemistry education literature about electrochemistry concepts such as electrolytes, redox equations, and about electrochemical (galvanic and electrolytic) cells. Other studies have considered teaching approaches aimed at improving learning and at overcoming misconceptions. This paper reviews these studies and considers strategies and approaches for the effective teaching of electrochemistry. Then, the review focuses on problem solving in equilibrium electrochemistry, especially problems involving the Nernst equation. The main findings of four studies with Greek university chemistry students, dealing with: (i) algorithmic problem‐solving ability; (ii) practice on problem solving; (iii) the effect of the format of a problem; and (iv) the construction and evaluation of a website devoted to electrochemistry problem solving, are reported.     

Characterization of sodium alginate membrane crosslinked with glutaraldehyde in pervaporation separation

Dense sodium alginate (SA) membranes crosslinked with glutaraldehyde (GA) have been prepared by the solution method, wherein a nonsolvent of SA (acetone) was used in a reaction solution instead of an aqueous salt solution. Through infrared radation, X-ray diffractometry, and the swelling measurement, the crosslinking reaction between the hydroxyl groups of SA and the aldehyde groups of GA was characterized. To investigate the selective sorption behavior of the crosslinked SA membranes, swelling measurements of the membranes in ethanol-water mixtures of 70–90 wt % ethanol contents were conducted by equipment that was able to measure precisely the concentration and amount of the liquid absorbed in the membranes. It was observed that the crosslinking could reduce both the solubility of water in the resulting membrane and the permselectivity of the membrane toward water at the expense of membrane stability against water. The pervaporation separation of a ethanol-water mixture was conducted with the membranes prepared at different GA contents in the reaction solution. When the membrane was prepared at a higher GA content, both flux and separation factor to water were found to be reduced, thus resulting from the more crosslinking structure in it. The pervaporation separations of ethanol-water mixtures were also performed at different feed compositions and temperatures ranging from 40 to 80°C. A decline in the pervaporative performance was observed due to the relaxation of polymeric chains taking place during pervaporation, depending on operating temperature and feed composition. The relaxational phenomena were also elucidated through an analysis on experimental data of the membrane performance measured by repeating the operation in the given temperature range. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 209–219, 1998