Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Műuegyetem Rakpart 3, Budapest, H-1111, Hungary.
Research Institute for Technical Physics and Materials Science, Hungarian Academy of Sciences, H-1121, Hungary.
J Nanosci Nanotechnol. 2019 Jan 1;19(1):498-501. doi: 10.1166/jnn.2019.15790.
In this study the effects of various anions (SO₄, ClO₄ and PO₄) were investigated on the hydrothermal treatment of WO₃ from Na₂WO₄ and HCl at 180 and 200 °C. The products were analyzed by XRD and SEM. With the usage of SO₄ the obtained product was hexagonal (h-) WO₃ in the form of nanorods at both temperatures. Applying ClO₄ resulted in a mixture of WO₃·0.33H₂O and small amount of m-WO₃ at 180 °C and pure WO₃·0.33H₂O at 200 °C. The morphology was consisted of cuboid shapes arranged into spherical structures at 180 °C and longitudinal ones at 200 °C. By the application of PO₄ no product formed at either temperature. Using the combination of SO₄, and ClO₄ the product was h-WO₃ at both 180 and 200 °C with rod-like crystals; thus, the effect of ClO₄ was overdominated by the SO₄ions. Utilization of PO₄ together with SO₄, and/or ClO₄ resulted again in no product, meaning that adding PO₄ to the reaction mixture completely blocks the hydrothermal formation of solid products by forming water soluble phosphotungstic acids.
在这项研究中，研究了不同阴离子（SO₄、ClO₄和 PO₄）对 WO₃ 的水热处理的影响，WO₃ 是由 Na₂WO₄ 和 HCl 在 180 和 200°C 下制备的。通过 XRD 和 SEM 对产物进行了分析。使用 SO₄，在两种温度下均获得了呈纳米棒状的六方（h-）WO₃。使用 ClO₄，在 180°C 下得到了 WO₃·0.33H₂O 和少量 m-WO₃ 的混合物，而在 200°C 下则得到了纯 WO₃·0.33H₂O。在 180°C 下，形貌由排列成球形结构的长方体组成，而在 200°C 下则由纵向的组成。使用 PO₄，在两种温度下均未形成产物。使用 SO₄ 和 ClO₄ 的组合，产物在 180 和 200°C 下均为 h-WO₃，具有棒状晶体；因此，ClO₄ 的影响被 SO₄ 离子所超越。再次将 PO₄ 与 SO₄ 和/或 ClO₄ 一起使用，导致仍然没有产物形成，这意味着向反应混合物中添加 PO₄ 通过形成水溶性磷钨酸完全阻止了固体产物的水热形成。
