海洋防污用新型TiO2/氟化丙烯酸纳米复合涂料的研制

合成了一种Ti O_2/氟化丙烯酸纳米复合涂料,对树脂和合成产物进行了一系列的检测。采用凝胶渗透色谱法和差示扫描量热法分别检测氟化丙烯酸树脂的重均分子量和玻璃化转变温度,红外光谱检测确认了纳米Ti O_2在树脂上的成功接枝,海洋浸没实验分析了复合涂层的防污程度。实验结果显示,通过添加表面改性的纳米Ti O_2能够显著提高氟化丙烯酸聚合物的防污性能,从而提供了一种无毒、环保的海洋防污涂料制备方法。     

一步固相法制备高性能Li_2MnSiO_4/C锂离子电池正极材料

采用一步固相法合成了Li_2MnSiO_4/C正极材料,利用XRD,EIS和循环伏安测试对该材料进行了结构和电化学性能表征.研究了一步固相法中添加不同比例的葡萄糖对Li_2MnSiO_4材料性能的影响.结果表明:葡萄糖作碳源复合可以提高Li_2MnSiO_4正极材料的充放电比容量和循环性能,同时在一步固相合成法中还能细化Li_2MnSiO_4正极材料颗粒.葡萄糖添加量为6%时,制备得到的Li_2MnSiO_4/C正极材料首次可逆放电比容量为213.1 mAh/g.     

GNR-TiO_2/g-C_3N_4异质结构的制备及其性能研究

采用二次凝胶-溶胶法和水热法合成了具有光催化效应的GNR-TiO_2/g-C_3N_4异质结构,并对其性能进行了研究.研究结果表明:GNR-TiO_2/g-C_3N_4异质结构表现出强的光催化活性,并在可见光照射下,对有机物亚甲基蓝有良好的催化效果.这主要归因于石墨烯纳米带作为载体,不仅增加了异质结构的比表面积,还使空穴-电子对的再结合率降低.     

GO/CoFe2O4催化过硫酸盐降解邻苯二甲酸二丁酯效能

为高效地去除水中环境激素类污染物,采用共沉淀法合成了氧化石墨烯负载钴尖晶石铁氧体(GO/CoFe_2O_4)催化剂,催化过硫酸盐(PMS)去除水中邻苯二甲酸二丁酯(DBP).采用SEM、TEM、XPS、XRD对催化剂进行表征,研究不同条件下催化PMS去除水中DBP的效果,提出催化PMS反应机理.结果表明,GO/CoFe_2O_4为颗粒状尖晶石结构,室温下,DBP初始浓度为2μmol/L、催化剂投量为0.1 g/L、PMS浓度为20μmol/L、pH为7时,GO/CoFe_2O_4催化PMS体系对DBP的去除率可达89%,使用5次后催化效果仅降低5%.该新型复合催化剂高效、具有磁性、方便回收,具有良好的工程应用前景.     

二氧化硫在氯化钙盐吸法应用中的反应特性

为探索氯化钙盐吸条件下SO_2可能的转化反应以及该类反应对氯化钙盐吸法测量烟气中SO_3的影响特性,采用一维立卧管式炉实验装置及控制变量法研究了水蒸气、氧气氛、温度、反应物浓度对SO_2与CaCl_2化学反应的影响,并理论分析了SO_2与CaCl_2可能的化学反应过程及对SO_3测量的影响.结果表明:在无CaCl_2样品条件下,SO_2并不能发生均相反应;在典型氯化钙盐吸法条件下,只有当H_2O及O_2同时存在时,SO_2可与CaCl_2发生明显化学反应;升高立卧管式炉温度及增加反应物浓度,SO_2的转化率相应升高,转化率约在2%~8%;理论分析表明,该反应在200℃及典型取样气氛下属于慢化学反应,在高浓度硫酸蒸汽存在下被严重抑制,减小了对SO_3测量的干扰,一定程度上证明了氯化钙盐吸法测量SO_3的可行性.     

可见光响应型(CuAg)xIn2xZn2(1-2x)S2光催化剂的光催化制氢

为实现可见光下分解水制氢,用沉淀煅烧法合成系列(CuAg)_xIn_2xZn2(1-2x)S₂光催化剂．采用X射线衍射仪(XRD)、紫外可见吸收光谱(UV-Vis)、电位粒径仪(DLS)、X射线能谱(EDS)、电感耦合等离子体质谱(ICP-MS)等方法研究了光催化剂的能带结构,评价其光催化性能．结果表明,随着组成配比x值的增加,光催化剂的光吸收从紫外光向可见光扩展,禁带宽度逐渐变小. 通过计算发现,光催化剂的导带电位逐渐接近氢的氧化还原电位．合成的(CuAg)_xIn_2xZn2(1-2x)S₂ (x=0.05~0.30)在可见光下都能光催化产氢,并且(CuAg)0.15In0.3Zn1.4S₂(即x=0.15)具有最高的光催化制氢活性．调节组成配比可调控光催化剂的能带结构,有助于获得具有高活性和稳定性的可见光响应型光催化剂．     

电催化剂及其对甲酸氧化的电催化性能

采用氨水调节的微波多元醇法合成了Pd/C和Pd2Pt/C催化剂,并使用透射电镜(TEM)和X-射线衍射(XRD)对催化剂的微观结构和形貌进行了表征.结果显示,在微波合成的电催化剂中Pd和Pd2Pt纳米粒子具有均匀的粒径,并高度分散在XC-72纳米碳载体上,Pd和Pd2Pt纳米粒子的平均粒径分别为54 和49 nm. 电化学测试结果显示,甲酸在Pd/C催化剂上氧化的起始电位和峰电位大大低于Pt/C催化剂,这是由于甲酸在Pd/C和Pt/C催化剂上不同的氧化途径引起的.结果还显示,甲酸在Pd2Pt/C催化剂和Pd/C催化剂上氧化的起始电位相同,而且在024和080 V有两个分别对应于甲酸在Pd和Pt催化剂的氧化, 说明微波合成的Pd/C和Pd2Pt/C催化剂对甲酸的氧化具有良好的电催化性能.     

Al_2O_3包覆对富锂锰基正极材料Li_(1.2)Mn_(0.54)Co_(0.13)Ni_(0.13)O_2的电化学性能影响

采用水热法合成富锂三元正极材料,探究了最佳包覆比例下Al_2O_3包覆对材料的电化学性能影响.采用扫描电镜(SEM)和X射线衍射仪(XRD)表征了富锂三元正极材料的表面形貌和结构,通过循环伏安(CV)、交流阻抗(EIS)技术分析了材料电化学性的影响因素.结果表明,通过异丙醇铝水解制得了氧化铝包覆层,提高了材料的比容量,稳定了材料的结构.     

H2SO3对X70钢在弱酸性溶液中的腐蚀行为的影响

用静态失重法、动电位扫描法、交流阻抗法结合扫描电镜、X射线能谱分析研究了H₂SO₃对X70钢在弱酸性溶液中的腐蚀行为的影响. 结果表明，随H₂SO₃浓度的增大， X70钢在弱酸性溶液中的腐蚀深度逐渐增大，电荷转移电阻依次减小，自腐蚀电流逐渐增大，自腐蚀电位先负移后正移. 当HAc-NaAc缓冲溶液中含有H₂SO₃时，X70钢在活性溶解过程中形成了吸附性中间产物Fe(HSO₃)_ad.     

N掺杂Co3O4纳米片的制备以及活化过一硫酸盐的性能研究

采用牺牲模板法合成N掺杂Co₃O₄纳米片（N-Co NS）,通过透射电子显微镜（TEM）、原子力显微镜（AFM）和光电子能谱（XPS）对制备材料的形貌结构、化学组成进行分析,并通过催化活化过一硫酸盐（PMS）降解水中双酚A （BPA）来探究催化剂的催化性能.实验结果表明与Co₃O₄纳米颗粒（Co NP）、Co₃O₄纳米片（Co NS）相比,N-Co NS表现出了较高的催化性能.在PMS浓度为2 mmol·L^-1、BPA初始质量浓度为50 mg·L^-1的反应条件下,N-Co NS在10 min内完全降解水中的BPA,表明N掺杂和二维纳米片结构有利于催化剂性能的提升.通过pH及离子影响实验证实N-Co NS在复杂水化学环境中仍具有较高的活性.此外结合自由基捕获实验和电子顺磁共振（EPR）测试证实反应体系中产生了高氧化活性的羟基自由基和硫酸根自由基.     

Molten Salt Synthesis of Ba（ Mgl／3Nb2／3 ）O3 Powder

The single-phrase Ba(Mgl/3Nb2/3)O3(BMN) powder was saccessfully prepared by the KCImolten salt synthesis(MSS) method. The temperature for single-phase BMN powders by MSS was about 400℃ lower than that by the solid-phase method. The average particle size (APS) was about 0.91,u.m at 900℃ and increased with increasing synhesis temperature. Based on the APS, the activation energy for particle growth in theMSS, whose value was 64. 1kJmol^-1.was attained. The sinterability of the powder prepared by MSS method wasbetter than that pretared by solid-phase method.     

Synthesis and performance of LiMnO<Subscript>2</Subscript> as cathodes for Li-ion batteries

Two structure types of LiMnO₂ were synthesized by sol-gel method and ion-exchange method respectively. The results indicate that orthorhombic phase LiMnO₂ is more stable than layered LiMnO₂, o-LiMnO₂ can be synthesized directly by sol-gel methods followed by heat-treated in argon, but layered LiMnO₂ was obtained only by indirect methods such as ion-exchange method. In this paper, we first synthesized layered NaMnO₂ by the sol-gel method, and then obtained layered LiMnO₂ by the ion-exchange method. The phase, constitution, chemical composition, and images of the products were tested by XRD, AAS (atomic absorption spectroscopy) and SEM. The electrochemical performances of the two structural types of LiMnO₂ are obviously different during the initial few cycles, but later they both have a good capacity-retaining ability. The capacity of layered structure LiMnO₂ is higher than that of o-LiMnO₂. ZHAO Shi-xi: Born in 1966 Funded by the National Natural Science Foundation of China (No.59972026)     

钙基吸附剂的改性

综合了6种钙基吸附剂的改性方法,分别为:加入有机酸;加入氯化氢;添加高熔点的金属氧化物,如MgO和MnO_2;在煅烧和碳酸化阶段加入蒸汽;通过高强度的声波脉;燃烧生物柴油的副产品。分析了6种方法的优缺点,研究了提高钙基吸附剂循环捕集CO_2能力的方法。     

CO2捕集技术的研究进展

化石燃料燃烧排放的CO_2是当今温室气体中CO_2污染的主要来源。介绍了CO_2捕集技术中吸附法、吸收法和膜分离法的研究进展,并分析了各种方法的特点,归纳总结了目前新型吸附/吸收剂中金属有机骨架、相变吸收剂、离子液体吸收剂和纳米流体吸收剂的研究成果。降低能耗和成本是今后研究工作的重点。开发新型吸附/吸收剂、优化反应过程和联合使用不同方法是未来CO_2捕集技术的发展方向。     

W波段毫米波晴空大气传输特性

为考察晴空大气对毫米波信号的衰减作用,基于大气分子吸收光谱参数数据库hitran2008,分析大气中对毫米波有吸收贡献的主要气体,采用Gross动力线型对分子谱线在远翼区的吸收进行精细建模计算,以逐线气体辐射计算方法计算水汽、氧气、臭氧等6种主要吸收气体的物性参数以及吸收光谱,分析均匀路径、非均匀路径大气对毫米波的衰减作用,并将逐线计算方法与Liebe模型方法的计算结果进行比对,结果表明二者符合较好.此外,将理论计算数据与94 GHz测试系统的测量数据进行对比,最大相对偏差为3.7%,进而验证模型的正确性.结果表明:在75～110 GHz毫米波段,水汽、氧气对毫米波信号衰减强烈,占总气体衰减的95%以上,毫米波信号在20 km左右高度水平传输时,需要考虑臭氧对信号的衰减作用,甲烷、一氧化碳、一氧化二氮对信号的衰减可忽略不计.研究结果可为毫米波雷达参数设计等工程应用提供参考.     

Combustion Synthesis of TiB2 Ceramics Powder from B2O3-TiO2-Mg System in Air Atmosphere

TiB2 ceramics powder was syuthesized from B2O3 - TiO2 - Mg system. The effects of TiB2 addition as diluent on the conbustion synthesis process were investigated. The results of thermodynanmic calculation and experiments stow that the increase of TiBz content ranging from 0 to 20wt% can reduce the adiabatic temperature Tad from 3100 Kto 2896 K and combustion temperature T,. from 2139 K to 1621 K respectively. The particle size and half width of the particle distributhm are also increased with the addition of TiB2 increasing from 0 to 20wt% . The combustion product is a mixture of TiB2 , MgO , and other intermediate phases. The leached produet contains mairdy TiBz, TiOz and TiN, and its oxygen content is 7.77wt% .     

Effects of drying method on preparation of nanometer α-Al2O3

Ammonium aluminum carbonate hydroxide （AACH） precursor was synthesized by the precipitation reaction of aluminum sulfate and ammonium carbonate. Then the precursor was dealt with five drying methods including ordinary drying, alcohol exchange, vacuum freeze-drying, glycol distillation, n-butanol azeotropic distillation respectively and calcined at 1 200℃ for 2 h to get α-Al2O3. The effects of drying methods on preparation of nanometer α-Al2O3 were discussed, and the optimal drying method was confirmed. The structural properties of powders were characterized by XRD, SEM and BET measurements. The results show that vacuum freeze-drying, glycol distillation and n-butanol azeotropic distillation can prevent the powders from aggregating, and among them the n-butanol azeotropic distillation is the best method. The nanometer α-Al2O3 powder with non-aggregation can be manufactured using n-butanol azeotropic distillation and the average particle size is about 40 nm.     

IR Spectra Analysis of SiO2-TiO2-GeO2 Gel Glass of CO2 Laser Transmitting Hollow Waveguide

Both titanium and germanium were introduced into silicon dioxide system by sol-gel method to move its region of anomalous dispersion caused by IR resonance absorption towards the wavelength of CO₂ laser. It is indicated by IR absorption spectra that as the content of SiO₂ decreases in this glass system TiO₂ and GeO₂ tends to exist in their own phases. As for the gel glass with a composition of 40 SiO₂·30TiO₂·30GeO₂, when the temperature is below 600°C, germanium atoms exist mainly in Ge−O−Ge bonds. With the temperature increasing from 800°C to 1000°C, titanium atoms in Si−O−Ti bonds abmost transform into Ti−O−Ti bonds. Furthermore, a large number of Si−O−Ti and Si−O−Ge bonds formed when the temperature approaches 800°C, which makes a notable IR absorption band round the wavelength of CO₂ laser. Therefore, sol-gel based SiO₂−TiO₂−GeO₂ gel glass is a candidate material for CO₂ laser hollow waveguide. JING Cheng-bin: Born in 1974. This work was partly financially supported by the Foundation of Key Teachers of Ministry of Education, China.     

二氧化钛光催化剂掺杂改性的研究进展

半导体材料TiO2作为光催化剂得到了广泛的研究和应用.介绍了TiO2光催化反应机理以及光催化剂掺杂改性的研究进展,包括金属离子、非金属以及金属/非金属共掺杂,并且指出了TiO2光催化剂改性的研究热点和研究方向.