花状Pt/Bi2WO6微米晶合成、表征及其高可见光催化性能

利用水热-光化学沉积法合成了一系列粒径为1.5~2μm的花状Pt/Bi2WO6微米晶.采用X射线衍射仪（XRD）、N2物理吸附、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、紫外可见漫反射光谱（DRS）、X射线光电子能谱（XPS）和傅里叶变换红外光谱（FT-IR）等手段进行表征.在可见光照射下（λ＞420 nm）,进行了光催化降解染料酸性橙Ⅱ的性能测试.表征和测试结果表明,这些多尺度花状Pt/Bi2WO6复合微米晶,在水溶液中进行光催化降解反应具有优越的性能.此外,沉积1%的Pt 纳米粒子可使光催化活性显著提高,为Bi2WO6的2.8倍.沉积的Pt纳米粒子由于产生表面等离子体的共振吸收,增强对可见光的吸收能力,同时降低了光生电子（e-）和空穴（h+）的复合,促进·OH 自由基的产生,因此能在很大程度上提高光催化活性.此外,这种特殊结构的Pt/Bi2WO6微米晶有利于在水溶液中进行分离和回收,提高催化剂的利用效率.     

微波法制备多孔Bi_2O_3/WO_3及其光催化降解苯酚的研究

以复合表面活性剂为模板剂,微波法制得铋掺杂WO3光催化剂。采用XRD、TEM和DRS等手段对所得样品分别进行表征。结果表明:微波加热所得的样品具有更好的介孔结构,且分散更加均匀。以苯酚为模拟废水,考察催化剂用量、反应温度、溶液pH值和铋掺杂量对苯酚光催化降解效果的影响。     

微米球光催化剂在环境净化及能源转化的研究进展

光催化在污染物降解及能源转化应用方面前景宽广。然而,大部分光催化剂因本身物理结构的缺陷而难以广泛运用。微米球光催化剂具有显著的优点,如低密度、高光捕获能力和载流子分离效率、优异的电子和光学性能、高比表面积、易回收、优良的传递性能和表面渗透能力。这些结构有利于提高光催化性能和实际运用,因而受到广泛关注。重点介绍并讨论了一些典型的微球光催化剂（TiO₂, ZnO, Bi₂WO₆, PbWO₄,BiFeO₃, BiOX (X = Cl, Br, I)等）的制备及这类光催化剂在环境净化和能源转化方面的研究进展,并展望了微米球光催化剂的发展方向。      

含钛钼钨的杂多酸盐催化剂的制备及性能研究

采用超声波法制备了纳米固载杂多酸盐催化剂HPAS／Ti02-WO3和HPAS／TiO2-MoO3，考查了其红外光谱及TEM，并在丙酸环己酯的合成中试验了其催化性能。实验表明，制备的催化剂具有良好的催化活性，丙酸环己酯的产率可达77．4％。     

超声场作用下薄膜型WO3-TiO2光催化剂制备与性能表征

在超声场作用下采用溶胶-凝胶法制备了纳米WO3-TiO2复合光催化剂。利用薄膜对罗丹明B溶液的光催化降解作用，考察了钨酸铵掺杂量、镀膜层数、烧结温度、烧结时间、基质、pH值、溶解氧及超声波等因素对光催化活性的影响，并与普通溶胶-凝胶法进行了比较。结果表明，在超声场作用下，溶胶的胶凝时间显著缩短，光催化剂颗粒粒径明显减小，催化活性显著提高，当钨酸铵掺杂量为0．5％（质量分数）、多孔钛片为基质、镀膜9层、575℃下烧结1h得到的WO3-TiO2薄膜的光催化活性最高。该温度下制备的WO3-TiO2薄膜几乎均为金红石型TiO2。     

制备工艺对钛酸钡基无铅高压陶瓷电容器材料性能的影响

以BaTiO3为基料,加入SrTiO3,CaCO3,Bi2O3·3TiO2等制备了(1-z)Ba1-x-ySrxCayTiO3·z(Bi2O3·3TiO2)系无铅高压陶瓷电容器材料,研究了制备工艺对材料性能的影响.结果表明,在保温时间一定的情况下,瓷料的最佳烧结温度取决于组分中Bi2O3·3TiO2含量,且烧结温度随着Bi2O3·3TiO2的含量的增加而降低;在BaTiO3中加入30％SrTiO3,10％ CaCO3和3％ Bi2O3·3TiO2时(均为摩尔分数),瓷料的最佳烧结温度为1240℃,其εr=3802,tgδ=4.2×10-3,Eb=9.2 kV·mm-1;并且在研究介温性能时,居里温度降低到35℃左右,拓宽了介电峰;当Bi2O3·3TiO2的含量增加到4％时,瓷料的最佳烧结温度为1220℃;在合理的烧结温度范围内,低温烧结和慢速升温将有利于细晶的致密化,从而改善高压陶瓷电容器的综合性能.     

小龙钨矿精选尾矿综合回收试验研究

根据试料性质研究结果,采用磁选-重选-浮选的联合工艺流程对某钨矿精选尾矿进行钨、铜、铋综合回收,对含WO3、Cu、Bi分别为2.38％、1.63％、0.98％的试料,开路试验可获得含Cu分别为23.9％、8.75％,回收率为63.21％、17.50％两种品质的铜精矿；含WO370.90％,回收率为20.66％高品位钨精...     

Luminescence Properties of Sm^3＋ doped Bi2ZnB2O7

The phosphors of （Bi1- x Smx ） 2ZnB2O7 （ x = 0. 01, 0. 03, 0. 05, 0. 07, and 0. 09） were synthesized by conventional solid state reaction. The purity of all samples was checked by X-ray powder diffraction （XRD）. XRD analysis shows that all these compounds are of a single phase of Bi2ZnB2O7, indicating that the Bi^3＋ in Bi2ZnB2O7 can be partly replaced by the Sm^3＋ without the change of crystal structure. The excitation and emission spectra at room temperature show the typical 4f-4f transitions of Sm^3＋ . The dominant excitation line is around 404 nm due to ^6H5/2→^4K11/2 and the emission spectrum consists of a series of lines at 563, 599, 646, and 704 nm due to ^4G5/2→^6H5/2, ^6H7/2, ^6H9/2, and ^6H11/2, respectively. The optimal concentration of Sm^3＋ in Bi2ZnB2O7 is about 3mol% （relative to lmol Bi^3＋ ） and the critical distance Rc was calculated as 2.1 nm. The temperature dependence of the emission intensity of Bi1.94Sm0.06ZnB2O7 was examined in the temperature range between 100 and 450 K. The quenching temperature where the intensity has dropped to half of the initial intensity is 280 K. The lifetime for Sm^3＋ in Bi1.94Sm0.06ZnB2O7 is fitted as a value of 0.29 and 1.03 ms.     

组分影响(Na1/2Bi1/2)TiO3介电性能的研究

采用正交设计试验法研究了配方对钛酸铋钠(Na1/2Bi1/2)TiO3(BNT)铁电陶瓷介电性能的影响,得到了影响BNT陶瓷介电性能的主次因素以及各因素水平影响其性能的趋势,进而得到了综合性能佳的BNT陶瓷.探讨了各组分对BNT陶瓷介电性能影响的机理,为BNT陶瓷材料的改性研究提供了依据.     

黄沙坪低品位钼、铋、钨、萤石、铁（石榴石）多金属矿体的矿物性质及破碎磨矿流程的研究

对黄沙坪钼、铋、钨、萤石、石榴石多金属矿体的矿物性质与磨矿流程进行了研究．结果表明,该矿体金属矿石品种多,粒度细,所采用的破碎磨矿流程适宜且节能．     

黄沙坪低品位多金属矿钼铋浮选回收的试验研究

文章研究了黄沙坪低品位钼铋钨萤石铁多金属矿中矿物含量低、粒度嵌布不均匀、氧化程度高的钼铋矿的浮选回收小型流程试验及工业试验研究。工业试验指标可从含Mo 0．108％,Bi0．03％的给矿得到含Mo 45．89％、回收率84．74％的钼精矿;含Bi 5．10％,回收率50．88％的铋精矿。     

F掺杂可见光催化剂Bi2MoO6的制备及其增强的光催化性能

通过简单的水热法成功合成了氟掺杂Bi2MoO6光催化剂,通过XRD、TEM、FT-IR、DRS等手段对合成产物进行了表征,研究了氟掺杂对Bi2MoO6的结构和光催化活性的影响。紫外可见漫反射光谱显示,掺氟的光催化剂在可见光区域具有更强的吸收。可见光照射下对罗丹明B的光催化降解实验表明,F/Bi2MoO6复合催化剂展示了增强的光催化活性。当F/Mo比为0.3时,复合催化剂表现出最高的光催化活性。这可能是由于F掺杂使催化剂的光生电子和空穴的再复合率降低,提高了催化剂的光量子效率,增强了催化剂的活性。     

Preparation and Photocatalytic Behaviors of Nanoporous Polyoxotungstate-Anatase TiO2 Composites

Nanoporous anatase TiO2 crystalline particles coupled with Keggin or Wells-Dawson unit, H3PW12O40/TiO2 or H6P2W18O62/TiO2, were prepared at a low temperature （200℃ ） using sol-gel method combined with hydrothermal treatment at programmed temperature. The as-prepared composites have uniform anatase phase, and they exhibit both micrand mesoporosities with pore sizes of 0.6 and 4.0 nm, respectively, and their average size is lower than 10 nm. Photocatalytic tests show the composites exhibit relatively higher photocatalytic activities to decompose the organocholorine pesticide hexachlorobenzene（HCB） than anatase TiO2, the starting polyoxotungstates, and EuEOa/TiO2 prepared by using sol-gel method, and this was attributed to （ 1 ） the synergistic effect of photoactive anatase TiO2 with the polyoxotungstate, and （2） the fascinating physical and chemical properties of the porous materials.     

Y_(2-x)Sm_xW_3O_(12)固溶体的制备及热膨胀性能研究

采用二次固相反应法成功制备出Y2-xSm(xWO4)(3x=0.0,0.2)、(x=1.0,1.4,1.8,2.0)系列固溶体,低掺杂量Y2-xSm(xWO4)(3x=0.0,0.2)为单斜结构(空间群:P2/m),高掺杂量Y2-xSm(xWO4)(3x=1.0,1.4,1.8,2.0)为单斜结构(空间群:C2/c);热重分析表明低Sm掺杂Y2-xSm(xWO4)3具吸水性,且随Sm含量增加而含水量减少,当x≥1.0时,样品完全不吸水;SEM分析了样品的断口形貌与晶粒尺寸;热膨胀性能测试表明,Sm掺杂量(x=0.0,0.2)的Y2-xSm(xWO4)3排除水分子后,具有较强的负热膨胀特性,而掺杂量(x=1.0,1.4,1.8,2.0)的Y2-xSm(xWO4)3具有正膨胀性能。     

从多金属矿中回收钨的研究

针对广东某钼多金属矿矿石性质复杂、有价矿物呈不均匀嵌布的特点,先采用螺旋选矿机和摇床将钨矿物和钼铋硫化矿富集,然后用摇床精选钨。在原矿品位WO30.601%的条件下,获得品位WO365.02%、回收率66.13%的重选钨精矿。对细粒级钨矿物即重选尾矿-0.2mm粒级通过浮选回收,获得品位WO365.20%、回收率15.47%的浮选钨精矿。采用重-浮联合流程回收钨,钨精矿品位WO3达65%以上,回收率81.60%,钨得到有效回收。     

Luminescent properties of Eu~(3+) doped Gd_2WO_6 and Gd_2(WO_4)_3 nanophosphors prepared via co-precipitation method

Eu3+ doped Gd2WO6 and Gd2(WO4)3 nanophosphors with different concentrations were prepared via a co-precipitation method. The structure and morphology of the nanocrystal samples were characterized by using X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM), respectively. The emission spectra and excitation spectra of samples were measured. J-O parameters and quantum efficiencies of Eu3+ 5D0 energy level were calculated, and the concentration quenching of Eu3+ luminescence in dif...     

TiO2／活性炭的制备与光催化性能

以活性炭(AC)为载体，采用Sol-Gel法制备纳米TiO2／AC复合催化剂，利用SEM，TG-DTA，XRD等对其组成、结构、尺寸等进行分析和表征；并用紫外灯为光源，通过可溶性罗丹明B的光催化降解反映对其光催化活性进行研究。结果表明，TiO2纳米粒子的尺寸范围在30nm～60nm之间，其中TiO2的晶型主要为锐钛矿；活性炭载体与TiO2结合牢固，TiO2纳米颗粒不发生二维粘结；TiO2／AC复合体的比表面积比活性炭载体的大，对罗丹明B在200min内达到完全降解，而P25需要5h，TiO2／AC复合体具有很强的光催化活性，并且制备的TiO2／AC复合体催化剂容易从溶液中分离。     

Effects of Doping CeO2, Er2O3 on Properties of TiO2-SiO2 Ceramics for Catalyst Supporter of deNOx

Effects of doping CeO2 and Er2O3 on the mechanical strength, thermal expansion coefficient, sintering temperature of TiO2-SiO2 ceramics were investigated. The experimental results and the microscopic analysis of SEM, XRD, TG-DSC, FT-IR and TEM show that adding CeO2 and Er2O3 into TiO2-SiO2 ceramics can prohibit the growth of its crystal grains, make their size uniform and form them into a dense structure, which finally enhance its mechanical behaviors, and the lower thermal expansion coefficient that leads to an excellent property of thermal shock resistance. After the reforming TiO2-SiO2 ceramics doped by CeO2 was sintered at 1380 ℃, the bending strength reached to 83 MPa, and the thermal expansion coefficient was 9.8×10-6/℃ within the temperature range of 25～800 ℃, which provides a promising basis of making equipped honeycomb catalyst of deNOx.     

Synergistic Effect of N and Ni2+ on Nanotitania in Photocatalytic Reduction of CO2

Nitrogen and nickel codoped nanotitania (N-Ni/TiO2) photocatalysts for producing methanol by photocatalytic reduction of CO2 were prepared by an improved sol-gol method. The catalysts were characterized by XRD, HRTEM, DES, FTIR, TG-DSC, and UV-Vis, respectively. The experimental results indicated that nano-N-Ni/TiO2 had better properties than the pure nanotitania (TiO2), N doped titania (N/TiO2), and Ni2+ doped titania (Ni/TiO2), considering their performance of photoresponse and photocatalytic reduction of CO2. The methanol yield could reach 482.0μmol/g-cat under optimal conditions. Additionally, the synergetic effect of N and Ni2+ on nano-TiO2 in photocatalytic reduction of CO2 was explained, and the mechanism of photocatalytic reduction CO2 on N-Ni/TiO2 catalyst was proposed.     

Bi2MoO6的形貌调控及其应用研究进展

光催化技术是解决环境污染、能源危机以及微生物净化的有效手段之一,在半导体领域得到了广泛的应用和飞速的发展,其中Bi₂MoO₆因其具有较强的可见光响应性能和较窄带隙,逐渐成为光催化领域的研究热点。然而,Bi₂MoO₆较差的化学表面形态和缓慢的载体迁移速率也限制了Bi₂MoO₆光催化材料的实际应用。经研究发现,形貌调控是增强铋系光催化性能的有效方法。本文总结了近年来Bi₂MoO₆光催化剂的形貌调控和应用研究进展,分别从Bi₂MoO₆的形貌分类、制备方法及其应用等方面进行综述,探讨了反应时间、温度以及溶液pH值等因素对Bi₂MoO₆形貌的影响,对Bi₂MoO₆形貌调控的未来发展趋势和面临的挑战进行分析总结。