A novel chiral 3D architecture containing left-handed helical chains constructed from vanadate clusters: [Zn(bpp)V2O6] (bpp = 1,3-di-4-pyridylpropane)

The hydrothermal reaction of Zn(NO₃)₂ · 6H₂O, bpp and NH₄VO₃ in water at 140 °C for 80 h yields an unprecedented chiral three-dimensional vanadium oxide complex, [Zn(bpp)V₂O₆] (1). The structure of 1 consists of wave-like two-dimensional networks, linked through {ZnO₂N₂} building blocks and bpp ligands into a three-dimensional covalently linked assembly. Furthermore, the title compound consists of infinite helical chains and all helical chains are left-handed.     

Pirimicarb degradation by BiVO4 photocatalysis: Parameter and reaction pathway investigations

In this study, bismuth vanadate is used as a visible-light catalyst for the photocatalytic degradation of pirimicarb insecticide. Significant amount of H₂O₂ is mandatory to obtain a significant photocatalytic activity of BiVO₄. The scavenger study indicates that holes and hydroxyl radicals are the main active species involved in the degradation of pirimicarb. Seven intermediates are identified and characterized through a mass spectra analysis. Based on this intermediate identification, a simple degradation pathway is proposed for the pirimicarb molecule, mainly through dealkylation and decarbamoylation. The practicality of this BiVO₄ photocatalyst is validated for the degradation of pirimicarb in environmental water samples, which indicates its potential for practical applications in water pollutant removal and environmental remediation.     

Synthesis and Characterization of Novel Materials,Tin Potassium Vanadate and Zirconium Potassium Vanadate Inorganic Multi-Component Ion Exchangers

Nano polyoxometallate-cation exchangers, tin potassium vanadate (TPV), and zirconium potassium vanadate (ZPV), with stereoregular particulate structures have been chemically synthesized using a homogeneous precipitation technique under a variety of conditions. The experimental parameters such as mixing, volume ratio, order of mixing and pH were established for the synthesis of the materials and fairly compromised to optimize the ion exchange properties of the produced ion exchangers. Structural characterizations of the materials were performed using XRF, XRD, thermal analysis, surface area and porosity measurements, and infra-red spectroscopy. The results were correlated to the lattice parameters, unit cell parameters, and space group of the exchangers. Scanning electron microscopy and atomic force microscopy revealed their sereoregularity in space. Compositions and molecular formulae of both the amorphous and crystalline materials have been investigated. Ion exchange properties and distribution coefficients, K _d , for some heavy metals namely, Co²⁺, Cu²⁺, Ni²⁺, and Cr⁶⁺ were measured at different pH values. TPV and ZPV selectivities have been examined by achieving some important and analytically difficult binary and multi-component separations. The results indicated that TPV is practically utilized for best separation of Co²⁺/Cu²⁺, Ni²⁺/Co²⁺, Cr⁶⁺/Co²⁺, Ni²⁺/Cu²⁺, Cr⁶⁺/Cu²⁺, Ni²⁺/Cr⁶⁺, Ni²⁺/(Co²⁺, Cu²⁺), and Ni²⁺/(Co²⁺, Cu²⁺, Cr⁶⁺), while ZPV could be efficiently used for separation of Cu²⁺/Co²⁺, Ni²⁺/Co²⁺, Cr⁶⁺/Co²⁺, Cu²⁺/Ni²⁺, Cr⁶⁺/Cu²⁺, Cr⁶⁺/Ni²⁺, and Cr⁶⁺/(Co²⁺, Cu²⁺, Ni²⁺).     

Preparation and upconversion luminescence of YVO4：Er^3＋,Yb^3＋

YVO_4:Er~(3+),Yb~(3+) with varying Yb~(3+) concentrations were prepared by a precipitation method.The results of X-ray diffraction (XRD) show that all the samples have a tetragonal zircon structure;the calculated average crystallite sizes are in the range of 14-22 nm.The lattice constants and cell volume of the samples decrease slightly with the increase in Yb~(3+) concentration.The upconversion luminescence spectra of all the samples were studied under 980 nm laser excitation.The strong green emission i...     

钒酸铋颜料的开发进展

新型无毒的钒酸铋颜料可作为毒性无机黄颜料的一种良好替代品。介绍了这类颜料的结构、性能、应用领域、制备工艺及后处理方法。指出我国进行钒酸铋颜料研究的必要性。     

钒酸铋研究新进展

纳米材料Bi VO4由于可见光响应好,禁带宽度(2.4 e V)小,在复杂有机物处理方面有突出的优势。综述了在钒酸铋研究中取得的成果,分析了存在的问题,并提出了研究展望。     

Independent Tuning of Optical Transparency Window and Electrical Properties of Epitaxial SrVO3 Thin Films by Substrate Mismatch

Transparent metallic oxides are pivotal materials in information technology, photovoltaics, or even in architecture. They display the rare combination of metallicity and transparency in the visible range because of weak interband photon absorption and weak screening of free carriers to impinging light. However, the workhorse of current technology, indium tin oxide (ITO), is facing severe limitations and alternative approaches are needed. AMO₃ perovskites, M being a nd¹ transition metal, and A an alkaline earth, have a genuine metallic character and, in contrast to conventional metals, the electron–electron correlations within the nd¹ band enhance the carriers effective mass (m*) and bring the transparency window limit (marked by the plasma frequency, ω_p*) down to the infrared. Here, it is shown that epitaxial strain and carrier concentration allow fine tuning of optical properties (ω_p*) of SrVO₃ films by modulating m* due to strain‐induced selective symmetry breaking of 3d‐t_2g(xy, yz, xz) orbitals. Interestingly, the DC electrical properties can be varied by a large extent depending on growth conditions whereas the optical transparency window in the visible is basically preserved. These observations suggest that the harsh conditions required to grow optimal SrVO₃ films may not be a bottleneck for their future application.     

Ag/BiVO_4脱氮光催化剂的制备与表征

以硝酸铋为铋源、偏钒酸铵为钒源,采用水热法制备了Ag掺杂改性的粉体钒酸铋(Ag/BiVO4)催化剂,采用XRD,UV-Vis DRS,SEM等手段对其理化性能进行了表征,并以模拟含氮油品为目标降解物,在可见光下评价其光催化脱氮性能。表征结果显示,Ag掺杂不会改变BiVO4催化剂典型的单斜白钨矿结构,可提高Ag/BiVO4催化剂对可见光的吸收能力,从而使其催化性能明显优于未改性的BiVO4催化剂,对模拟油品中的吡啶表现出良好的可见光降解效果。对于50 mL吡啶含量为50μg/g的模拟油品,当Ag掺杂量(理论计算值)为5%(w)时,催化剂最佳用量为0.05 g,在可见光下照射2.5 h,模拟油品中吡啶的降解率可达86.7%。