【摘要】 目的以Ta₂O₅和KCl为原料,制备高温相K₆Ta_10.8O₃₀棒状粒子,探究合成条件对其形成的影响。方法采用熔盐法合成高温相K₆Ta_10.8O₃₀棒状粒子,利用XRD,FE-SEM,EDX等分析手段对合成产物的形貌、化学组成及晶相结构进行表征,研究了反应温度和反应时间对形成高温相K₆Ta_10.8O₃₀棒状粒子的影响。结果 Ta/K摩尔比为0.011,在1 200℃反应2 h,可制得纯相且形貌规整的K₆Ta_10.8O₃₀棒状粒子,粒径约4μm,长约44μm。结论在KCl—Ta₂O₅二元体系的反应中,可得到低温相K₂Ta₄O₁₁和高温相K₆Ta_10.8O₃₀ 2种产物,适当地提高反应温度相较于延长反应时间更有利于高温相K₆Ta_10.8O₃₀棒状粒子的形成。合成样品掺杂Ag之后,在模拟太阳光照射下,高温相Ag-K₆Ta_10.8O₃₀比低温相Ag-K₂Ta₄O₁₁样品具有较高的可视光催化活性。更多还原

【Abstract】 Purposes—To prepare high-temperature phase K₆Ta_10.8O₃₀ rod-like particles with tantalum pentoxide and potassium chloride as raw materials, and explore the influence of synthesis conditions on the particle formation. Methods—K₆Ta_10.8O₃₀ rod-like particles were synthesized with molten-salt growth method. The effects of the temperature and time of calcination on the formation of K₆Ta_10.8O₃₀ rod-like particles were investigated by characterizing crystal structure, morphology and chemical components of the synthesized samples with XRD, FE-SEM and EDX. Result—K₆Ta_10.8O₃₀ rod-like particles can be prepared when synthesis conditions are that the molar ratio of Ta to K is 0.011 and the temperature and time of reaction is 1 200 ℃ and 2 hours respectively. These particles are about 44 μm in length and 4 μm in diameter. Conclusion—Two products, K₂Ta₄O₁₁ and K₆Ta_10.8O₃₀, can be obtained in the reaction of KCl-Ta₂O₅ binary system. Appropriately raising the reaction temperature is more conducive to the formation of high temperature phase K₆Ta_10.8O₃₀ rod-like particles than prolonging the reaction time. After doping the synthesized samples with Ag, the high temperature phase Ag-K₆Ta_10.8O₃₀ has higher visible photocatalytic activity than that of low temperature phase Ag-K₂Ta₄O₁₁ under simulated solar irradiation.更多还原