Investigation on Biomass-mediated Synthesis of Silver nanoparticles and Ag/α-Al2O3 Catalysts for Ethylene Epoxidation

银纳米材料是贵金属纳米材料的重要组成之一，由于其具有特殊的热学、磁学、光学、力学、化学等性质，被广泛地应用于超导材料、抗菌材料、光电器件、生物医学材料等领域，更在很早之前就作为一种性能良好的催化材料广泛用于部分氧化和还原反应的催化体系。近年来，关于材料制备过程绿色化的研究日趋活跃，纳米材料的绿色制备技术也受到越来越多的关注。利用生物质这一可再生的绿色资源合成贵金属纳米材料，为现代纳米材料的制备技术开辟了一条崭新的途径，成为当今的研究热点。近十年来，研究者们尝试采用多种微生物或植物生物质还原制备银纳米材料，该方法不仅充分利用了丰富的生物质资源，更加环保和安全，而且温和的反应条件可以降低能源及资源...Silver nanomaterials have been widely used in many fields such as construction of superconducting device, anti-bacterial materials, photonics, biomedicine due to their special thermodynamical, magnetic, optical and chemical properties. Also, they have performed very well to catalyze partial oxidation and reduction reactions. In recent years, green synthesis of nanomaterials attracts increasing att...学位：工学博士院系专业：化学化工学院化学工程与生物工程系_工业催化学号：2062007015357

芳樟叶浸出液还原制备对硝基苯酚加氢银催化剂

采用芳樟叶浸出液,通过原位还原和等体积浸渍的方法制备负载型纳米银催化剂,并以对硝基苯酚(4-NP)加氢反应为模型反应,考察催化剂载体,焙烧条件等对负载型纳米银催化剂性能的影响,并采用扫描电镜(SEM),热重分析(TG)和红外光谱(FT-IR)等表征手段对催化剂进行表征。结果表明,以TiO_2为载体制备的纳米银催化剂具有较好的催化活性;植物还原法制备的催化剂表面纳米银颗粒较小((7.3±2.4)nm),催化效果较好。当体系中Ag与4-NP的物质的量之比为1:230时,完全反应时间小于或等于10 min。对催化剂进行一定条件的焙烧处理,能在一定程度上提高催化剂的活性和重复使用性,将催化剂于400℃下焙烧1h,催化活性最佳:将催化剂于400℃下焙烧2h,催化剂重复使用性最好。对芳樟叶浸出液与银的作用机理进行初步研究,表明劳樟叶浸出液中的杂环化合物能通过羰基与银络合,从而起到防止催化剂表面纳米银颗粒团聚的作用

生物法制备纳米银溶胶的稳定性

利用生物还原法制备纳米银溶胶,借助于UV-Vis表征技术对其热稳定性和化学稳定性进行考察。结果表明:生物法制备的纳米银溶胶在100℃下加热6h,UV-Vis谱图未发生明显变化;H+和具有高价阳离子的电解质对其稳定性的影响明显;OH-对银溶胶的稳定性影响相对较弱。生物法制备的纳米银溶胶在热稳定性、化学稳定性方面均略优于柠檬酸三钠法制得的银溶胶

Green Synthesis of Potassium Diformate

以甲酸和氢氧化钾为原料,不外加任何溶剂一步合成二甲酸钾。通过单因素实验,考察了原料配比、反应温度和反应时间对产品质量与收率的影响。采用正交实验进一步优化了合成工艺,确定了最佳工艺条件:n(HCOOH)/n(KOH)=2.2、反应温度70℃、反应时间30 m in,在该条件下,二甲酸钾产品收率达98%以上。所得产品经红外光谱分析及熔点测定,其结果与文献报道一致。反应过程绿色化,有很好的原子经济性。Potassium diformate was synthesized without solvent,using formic acid and potassium hydroxide as raw materials.The optimal conditions for the reaction were:molar ratio of HCOOH to KOH 2.2∶1,reaction temperature 70 ℃ and reaction time 30 min.Yield of the process was over 98% under the optimal conditions.The infrared spectrum and melting range of the product were in good agreement with those reported in literature.The technology developed in this study could be an environmentally benign synthesis route with efficient atom economy

贵金属纳米颗粒及其催化剂的生物还原制备技术

利用自行筛选的具有强还原能力的菌株制备得到银纳米颗粒,所得颗粒的粒径基本在10 nm以下,主要集中在2~8nm。将生物还原过程进一步引入催化剂制备过程,得到负载型银催化剂和负载型钯催化剂,并将催化剂分别应用于1,2-丙二醇空气氧化合成丙酮醛、CO氧化生产CO2以及蒽醌加氢反应中

Preparation of Pd/Tio_2 Photocatalysts by a Bioreduction Method

纪镁铃（1986-）,女,本科生;李清彪(1963-)男,教授,博士生导师,通讯联系人. E-mail:[email protected][中文文摘]用芳樟叶煮液将 PdCl_2还原成 Pd 单质纳米颗粒,将其沉积于 TiO_2上制得 Pd/TiO_2催化剂,采用X射线衍射(XRD),扫描电镜(SEM)和能量色散谱仪(EDS)对催化剂进行表征,并以甲基橙为目标降解物评价 Pd/TiO_2催化剂的光催化降解活性。结果表明,Pd/TiO_2催化剂中的 Pd 纳米颗粒的平均粒径小于10 nm,能够很好地分散在 TiO_2表面,且不改变 TiO_2锐钛矿的晶型结构。与未负载 Pd 的 TiO_2催化剂相比,Pd/TiO_2光催化剂对甲基橙有更高的光催化降解活性,能够提高甲基橙的降解速率。在实验范围内,Pd 与 TiO_2质量比为5%的催化剂活性最高,反应30 min 甲基橙就能完全降解,而空白 TiO_2催化剂在反应1h 时降解率只达到95%。Pd 与 TiO_2质量比为5%的 Pd/TiO_2光催化剂矿化率可达到96.2%,且重复使用仍能保持良好的催化活性。[英文文摘]Palladium nanoparticles was deposited on the surface of titanium dioxide for the preparation of the Pd/TiO_2 photoeatalysts by a novel bioreduction method.PdCl_2 as the Palladium precursor was reduced to form Pd nanoparticles by the extract of cinnamornum carnphora leaf.The catalysts were characterized by X-ray diffraction (XRD),scanning electron microscope (SEM) and energy dispersive spectrometer (EDS).The photocatalytic degradation of methyl orange was used to test the photocatalytic activity of the catalsts.The results indicated that the average diameter of the Pd nanoparticles obtained by this bioreduction method was less than 10 nm.The Pd nanoparticles werw well dispersed on the surface of TiO2 without changing the anatase type of TiO2.Pd/TiO2 catalysts showed higher photocatalytic activity compared with blank TiO2 catalyst. The methyl orange degradation ratio of blank TiO2 catalyst in 60 min was only 95%,however,catalyst with 5% mass ratio of Pd to TiO2 showed the highest activity in the experiment which could achieve complete degradation within 30 min.96.2% of mineralization was obtained in the case of the photodegradation by the catalyst with 5% mass ratio of Pd to TiO2,moreover,the photocatalytic activity of this catalyst did not decrease when it was used repeatedly.国家自然科学基金(20576109); 国家高技术研究发展计划(2007AA032347); 福建省自然科学基金(2008J0169

Biosynthesis of Silver Nanoparticles Using Extract of Pichia Pastoris

侍者简介:洪露薇(1987一) .女，本科生，李消彪(1963一) .男，博士，数授，博士生导师，通讯联系人. E-mail: [email protected][中文文摘]采用毕赤酵母的提取液与银氨溶液反应制备银纳米颗粒(AgNPs),并考察了pH值对AgNPs的影响。结果表明:酸性条件下,反应速率缓慢,且生成的AgNPs呈多分散性;在一定范围内(pH值小于12.50),碱性条件有利于提高反应速率,且随着pH值的提高,AgNPs粒径分布变窄;当pH值继续提高(pH值为12.80),AgNPs发生团聚沉淀。[英文文摘]The Ag nanoparticles(AgNPs) were synthesized by the extract of Pichia pastoris,a non-pathogenic yeast,and the effects of pH on the reaction were investigated.The results showed that under acidic condition the reaction rate was slow and the AgNPs were polydisperse.When pH was below 12.50,the reaction rate increased with the increasing of pH and the distribution of the particle size was narrow;when pH reached 12.80 or above 12.80,aggregation of AgNPs appeared.国家高技术研究发展计划(2007AA03Z347);国家自然科学基金(20776120);福建省自然科学基金(2008J0169

Effects of Cd and its Accumulation on Several Common Leaf Vegetables in Southern China

设置0,5,15,30 mg/L 4个Cd浓度的水培试验,研究Cd对几种叶菜的耐性和累积效应。结果表明, Cd毒害引起菠菜、茼蒿、竹芥菜新叶枯焦、严重黄化,生长缓慢,产量显著减少,其影响大小顺序为竹芥菜>茼蒿、结球白菜>菠菜、生菜、油菜>小白菜。Cd在不同蔬菜类型的累积浓度大小顺序为茎叶:茼蒿>油菜、小白菜>结球白菜>竹芥菜>生菜>菠菜;根:茼蒿>结球白菜、油菜、小白菜>竹芥菜>生菜>菠菜。蔬菜茎叶对Cd的累积总量大小顺序为:油菜、结球白菜>苘蒿>小白菜、竹芥菜>菠菜、生菜。Seven main leaf vegetables cultivars[Brassica campestris L.ssp.pekinensis(Lour)Olsson,Apinacea oleracea L.var.spinosa Moench,Brassica Chinensis var.tsai-tai,Brassica juncea Coss.Bailey var.foliosa,Brassica campestris ssp.Chinensis M,Chrysanthemum coronavium var.spatisum,Lactuca sativa var.crispa L.]grown in Southurrn area were chosen and grown under different concentrations of cadmium(0,5,15,30 mg/L)using hydroponics system to evaluate the impacts of Cd on the growths and yields of leaf vegetables,toxic-symptoms and their accumulation of Cd.Cd contents in different parts of plant were measured after harvest.The results showed that, after different contents of Cd were supplied for three weeks,toxic-symptoms of yellow leaf was apperence seriously in spatisum、spinach、juncea,the yields of all vegetables were all decreased significantly compared with the control. The inhibiting rate were found to be following order:Juncea>spatisum,pekinensis>spinach,lettuce,tsai-tai>Chinensis.Most of Cd absorbed by plant was accumulated in roots,little of them was transported to the aboveground portions.Cd concentrations of leafs and roots were found to follow the sequence:spatisum>pekinensis (root),tsai-tai,Chinensis>pekinensis(leaf)>Juncea>lettuce>spinach.The order of Cd accumulation in different leaf vegetables was:tsai-tai,pekinensis>spatisum>Chinensis、Juncea>lettuce>spinach.厦门市科技局项目(3502Z20071098)资助

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel