等离子体修饰TiO_2及其响应光谱红移

TiO2在光催化方面应用前景十分广阔,而阻碍其应用的是它的宽禁带,因此研究开发响应光谱红移的TiO2就成为当前光催化剂研究的重要课题。等离子体处理是修饰TiO2的一种有效方法,目前等离子体修饰TiO2及其响应光谱红移的研究取得了一定进展,等离子体修饰的TiO2表面生成了氧空穴,并形成了原子掺杂,减小了禁带宽度,使其响应光谱红移。本文综述了目前该领域的研究现状,并对今后的研究做了展望。     

Ir（Ⅳ）—KBrO3—DBS—偶氮氯膦催化分光光度法测定微量铱的研究

ＫＢｒＯ３－ＤＢＳ偶氮氯膦在０．８ｍｌ．Ｌ＾－１的Ｈ２ＳＯ４介质中长时间加热亦无明显褪色现象，但在有微量铱存在时，褪色反应在３ｍｉｎ内完成，且与Ｉｒ（Ⅳ）的浓度有良好的线性关系，据此建立了微量铱的催化褪色分光光度分析法，其检出限为０．０１μｇ．１０ｍＬ＾－１铱的含量在０．０１－０．２０μｇ．１０ｍＬ＾－１范围内符合比尔定律。     

酞菁化合物LB单分子膜的SERRS

酞菁类化合物具有优良的光电特性,选择适当的取代侧链可得到稳定的LB成膜材料,可望在微电子器件等方面获得重要的应用.本工作观测了四-4-(2,4-二特戊基苯氧基)酞菁铜(CuPc(Dt-PP)_4)在银岛膜上的LB单分子层的表面增强共振拉曼散射(SERRS)光谱。比较其固体粉末的共振拉曼散射(RRS)光谱,讨论了酞菁铜分子大环在载片表面的取向及其可能的原因。1 实验CuPc(Dt-PP)_4样品由陈文启等合成,经元素分析、IR、NMR、色谱等研究确认其结构如图1所示.银岛膜用真空蒸镀法制备在玻璃载片上。用同时蒸镀在铜网上的银膜的透射电     

用热重分析法研究氢氧化镧的热分解过程

在研究固相交换反应过程中,我们对氢氧化镧进行了热重分析,发现氢氧化镧的热分解过程是分两步进行的,由其热重曲线计算了氢氧化镧热分解反应的活化能和反应级数。     

舞花姜的化学成分

舞花姜（Ｇｌｏｂｂａｒａｃｅｍｏｓａｓｍｉｔｈ）为姜科舞花姜属植物,产于我国南部、西南部等地。其根和果实在民间药用,有健胃、消炎的功能,用于治疗胃炎、消化不良、急慢性肾炎等［１］。尚未见有关舞花姜属植物化学成分和药理活性的研究报道,为此我们对其地下部分的化学成分进行了研究。乙醇提取物的石油醚可溶部分经硅胶柱和萄聚糖凝胶柱层析分离得到五个化合物,经光谱鉴定为木栓酮（ｆｒｉｅｄｅｌｉｎ１）,ｃｙｃｌｏｅｕｃａｌｅｎ－ｏｌ（２）、３－羟基－豆甾－５烯－７－酮（３－ｈｙｄｒｏｘｙ－ｓｔｉｇｍａｓｔ－５－…     

硫化物/Ru(Ⅱ)结合物复合敏化TiO_2纳米多孔膜

用光电化学方法研究了Cds、Pbs和RuL2（NCS）2（L＝2.2′-bipydine-4.4′-dicarboxylicacid）复合敏化TiO2。纳米晶电极的光电化学行为．结果表明，采用复合敏化比用rul（Ⅱ）络合物单独敏化TiO2。纳米晶电极效果好，大大提高了光电转换效率．主要原因是采用复合敏化，可防止TiO2导带上由光注入产生的电子的反向转移，避免了电子的损失．     

Metal–Organic Framework Membrane Nanopores as Biomimetic Photoresponsive Ion Channels and Photodriven Ion Pumps

Biological ion channels and ion pumps with sub‐nanometer sizes modulate ion transport in response to external stimuli. Realizing such functions with sub‐nanometer solid‐state nanopores has been an important topic with wide practical applications. Herein, we demonstrate a biomimetic photoresponsive ion channel and photodriven ion pump using a porphyrin‐based metal–organic framework membrane with pore sizes comparable to hydrated ions. We show that the molecular‐size pores enable precise and robust optoelectronic ion transport modulation in a broad range of concentrations, unparalleled with conventional solid‐state nanopores. Upon decoration with platinum nanoparticles to form a Schottky barrier photodiode, photovoltage across the membrane is generated with “uphill” ion transport from low concentration to high concentration. These results may spark applications in energy conversion, ion sieving, and artificial photosynthesis.     

Electrocatalytically Active Fe‐(O‐C2)4 Single‐Atom Sites for Efficient Reduction of Nitrogen to Ammonia

Single‐atom catalysts have demonstrated their superiority over other types of catalysts for various reactions. However, the reported nitrogen reduction reaction single‐atom electrocatalysts for the nitrogen reduction reaction exclusively utilize metal–nitrogen or metal–carbon coordination configurations as catalytic active sites. Here, we report a Fe single‐atom electrocatalyst supported on low‐cost, nitrogen‐free lignocellulose‐derived carbon. The extended X‐ray absorption fine structure spectra confirm that Fe atoms are anchored to the support via the Fe‐(O‐C₂)₄ coordination configuration. Density functional theory calculations identify Fe‐(O‐C₂)₄ as the active site for the nitrogen reduction reaction. An electrode consisting of the electrocatalyst loaded on carbon cloth can afford a NH₃ yield rate and faradaic efficiency of 32.1 μg h^?1 mg_cat.^?1 (5350 μg h^?1 mg_Fe^?1) and 29.3 %, respectively. An exceptional NH₃ yield rate of 307.7 μg h^?1 mg_cat.^?1 (51 283 μg h^?1 mg_Fe^?1) with a near record faradaic efficiency of 51.0 % can be achieved with the electrocatalyst immobilized on a glassy carbon electrode.     

大孔树脂-高速逆流色谱分离纯化薇甘菊中的黄酮类化合物

该文建立了大孔树脂-高速逆流色谱分离薇甘菊中黄酮类物质的方法。分离条件为:采用大孔树脂AB-8,洗脱液为50%（v/v）乙醇水溶液,高速逆流色谱溶剂体系为正丁醇-乙酸-水（4：1：5,v/v）。从薇甘菊中分离到4种黄酮类物质:槲皮素-3-O-芸香糖苷（纯度90.2%）、山奈酚-3-O-芸香糖苷（纯度98.55%）、木犀草苷（纯度98.33%）和紫云英苷（纯度99.23%）。建立的大孔树脂-高速逆流色谱方法简单、高效,可扩展应用于从其他植物中分离黄酮类物质。     

Enzymetically Regulating the Self‐Healing of Protein Hydrogels with High Healing Efficiency

Enzyme‐mediated self‐healing of dynamic covalent bond‐driven protein hydrogels was realized by the synergy of two enzymes, glucose oxidase (GOX) and catalase (CAT). The reversible covalent attachment of glutaraldehyde to lysine residues of GOX, CAT, and bovine serum albumin (BSA) led to the formation and functionalization of the self‐healing protein hydrogel system. The enzyme‐mediated protein hydrogels exhibit excellent self‐healing properties with 100 % recovery. The self‐healing process was reversible and effective with an external glucose stimulus at room temperature.