四氯化钛精致尾渣制备钒酸铁的研究

对四氯化钛精致尾渣进行酸浸,考察液固比、盐酸用量、浸出温度、浸出时间对钒浸出率的影响,结果表明,在液固比2∶1、38%盐酸与水的体积比1.1∶1、浸出温度40℃、浸出时间30min的条件下,钒浸出率可以达到97.1%。酸浸液调节pH后,在沉钒温度40℃、酸浸液钒初始浓度小于6g/L、终点pH1.4~2.0、氧化剂用量为理论量的5~6倍的条件下,钒沉淀率达到95.4%,沉淀物550℃煅烧3h后可以得到钒酸铁。沉钒渣和废水中和渣满足GB18599—2001中一般工业固体废物永久堆放的要求。     

Cu掺杂FeVO4光催化剂的制备及其光催化性能

为进一步提高钒酸铁(FeVO4)光催化活性,采用液相沉淀法分别制备钒酸铁和钒酸铜前躯体,再将钒酸铁和钒酸铜前驱体混合后进行热处理,制备了铜掺杂钒酸铁光催化剂,并采用X射线衍射(XRD)、扫描电子显微镜(SEM)、表面积(BET)和X射线光电子能谱分析(XPS)对样品进行表征和分析.在可见光照射下,通过光催化降解甲基橙溶液评价Cu掺杂对FeVO4光催化剂活的影响.结果表明,Cu/FeVO4光催化剂为三斜型,当掺杂质量分数大于5%时,晶体中出现新相Cu3Fe4(VO4)6;掺杂后样品的表面形貌产生了变化,但其比表面积变化较小;Cu/FeVO4样品的光催化活性大幅提高,主要是由于FeVO4和新相间起到类似复合半导体的作用;在所进行实验的条件下,钒酸铜的最佳掺杂质量分数为5%时,掺杂后的FeVO4对甲基橙溶液的脱色率较未掺杂前提高30%左右.     

新型铋黄颜料的制备

以Bi（NO3）3·5H2O、NH4VO3和（NH4）6Mo7O24为原料,研究了浓度、pH值、反应温度、反应时间等工艺条件对纳米级钒钼酸铋（铋黄）粉末制备的影响。采用X射线粉末衍射表征其物相结构,透射电子显微镜表征产物的形貌和微观结构。产物粒径及比表面积采用激光粒度分布测试仪和比表面积测试仪测定。研究结果表明：采用此技术制备的纳米级铋黄颜料,与同类颜料比较性能优越。     

Fabrication of the hydrogen-evolving photocatalyst with mesoporous structure

The photocatalyst TiO₂ with a wormhole-like mesoporous structure and narrow pore distribution were successfully synthesized using triethanolamine as template. The complex oxides InVO₄ with a relatively high surface area, a visible light active hydrogen-evolving photocatalyst, were obtained by means of the templating hydrothermal method with a variety of surfactants. InVO₄ with wormhole-like structure were fabricated by templating of cetyltrimethylammonium bromide. By comparing with the non-mesoporous samples, the mesoporous photocatalysts exhibited higher photocatlytic hydrogen evolution activity for water splitting in the absence and in the presence of oxalic acid.     

Synthesis of novel photocatalytic InVO4-TiO2 thin films with visible light photoactivity

Novel InVO₄-TiO₂ thin films were synthesized by introducing nano InVO₂ into the TiO₂ thin films via a sol-gel method. The photocatalytic efficiency of InVO₄-TiO₂ thin films was investigated by photodegrading of methyl orange in aqueous solution under visible light irradiation. A wide range of characterization techniques, such as X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), UV-vis absorption spectroscopy (UV-vis), were applied to characterize the obtained thin films. The results indicated that the InVO₄-TiO₂ thin films consist of uniform anatase TiO₂ crystals of 70-80 nm with highly dispersed orthorhombic InVO₄ nanocrystals. The decoloration of methyl orange results illustrated that the InVO₄-TiO₂ thin films with 0.5 wt.% InVO₄ showed the best photoactivities under visible light irradiation, the decoloration rate reached 32.5% after irradiated for 15 h. The InVO₄-TiO₂ thin films exhibited photoactivity under visible light after doped InVO₄ in the TiO₂ films.     

硼和铒共掺杂BiVO_4光催化降解罗丹明B的研究

通过柠檬酸络合法合成硼和铒共掺杂Bi VO4,并对其进行XRD、UV-Vis的表征以分析合成材料的物相、形貌。同时考察溶液的初始浓度、p H、催化剂投加量以及光照强度等因素在可见光的照射下对罗丹明B光催化降解的影响。实验结果表明:在50 m L罗丹明B水溶液中,初始质量浓度为10 mg/L,p H=3,催化剂投加量为0.015 g,光照距离14 cm,B-Er共掺杂Bi VO4对罗丹明B有较好的光催化活性,反应50 min后,降解率可达90%以上。     

钒酸钙冶炼中钒铁工艺研究

以钒酸钙为原料,将钒酸钙粉末熔片后,采用铝热法冶炼中钒铁,可获得合格的钒铁产品。钒酸钙冶炼钒铁过程平稳、可控,回收率可达97%以上,同时因钒酸钙制取时不产生难处理的高氨氮废水,相较于传统的氧化钒-钒铁的生产工艺路线有较大的环保优势。     

钒酸盐类光催化剂的研究进展

金属钒酸盐主要应用于荧光材料、激光材料和可充电锂电池阴极材料的制备;近来,作为一类新型高活性光催化剂,已引起人们普遍关注,但相关研究报道较少.本文综述了BiVO_4、InVO_4、Ag_3VO_4、FeVO_4等钒酸盐类光催化剂的合成与改性方法,分析比较了不同条件下催化剂的光催化活性,指出了该研究领域中需要解决的一些问题.     

Bitter gourd-shaped Ni3V2O8 anode developed by a one-pot metal-organic framework-combustion technique for advanced Li-ion batteries

The present study reports on the one-pot synthesis of Ni₃V₂O₈ (NVO) electrodes by a simple metal organic framework-combustion (MOF-C) technique for anode applications in Li-ion batteries (LIBs). The particle morphology of the prepared NVO is observed to vary as irregular rods, porous bitter gourd and hybrid micro/nano particles depending on the concentration of the framework linker used during synthesis. In specific, the orthorhombic phase and the unique bitter gourd-type secondary structure comprised of agglomerated nanoparticles and porous morphologies is confirmed using powder X-ray diffraction, electron microscopies, X-ray photoelectron spectroscopy and N₂ adsorption–desorption measurements. When tested for lithium batteries as anode, the bitter gourd-type NVO electrode shows an initial discharge capacity of 1362 mA h g⁻¹ and a reversible capacity of 822 mA h g⁻¹ are sustained at a rate of 200 mA g⁻¹ after 100 cycles. Moreover, at 2000 mA g⁻¹, a reversible capacity of 724 mA h g⁻¹ is retained after 500 cycles. Interestingly, the porous bitter gourd-shaped NVO electrode registered significantly high rate performance and reversible specific capacities of 764, 531 and 313 mA h g⁻¹ at high rates of 1, 5 and 10 A g⁻¹, respectively.     

钒酸镍锂离子电池负极材料的研究进展

综述了近年来国内外关于钒酸镍材料的合成方法、结构性质以及应用于锂离子电池新型负极材料的研究进展。钒酸镍(Ni3V2O8、NiV3O8等)电极材料具有成本低、环境友好、比容量高、倍率性能优异等优点,但其在充放电过程中体积的巨大变化、电导性差以及比表面积低等问题严重影响了其规模化应用。该文从三个方面阐述了近年来通过电极材料微纳米化、复合化、表面包覆等手段有针对性的进行钒酸镍电极材料改性的研究进展,积极探索了高性能钒酸镍材料的合成方法,展望了今后重点开展的研究方向,对于钒酸镍材料的广泛应用具有一定的学术价值和实用意义。