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采用碱性水热合成法制备纳米钛酸盐,研究盐酸后处理对纳米钛酸盐-二氧化钛形貌及光限幅效应的影响.采用X射线衍射分析仪、透射电子显微镜和扫描电子显微镜对样品的晶型转变及形貌演变进行表征,通过紫外-可见光谱与开孔Z扫描激光测试技术,研究样品的线性光学与非线性光学效应.结果表明,当酸处理浓度介于0.10-0.55 molL-1范围时,水热产物由钛酸盐转变为钛酸盐/二氧化钛混合物;当酸处理浓度高于0.78molL-1时,钛酸盐近乎完全转变为金红石型二氧化钛.在酸处理过程中,纳米钛酸盐晶型转变速率与盐酸的浓度直接相关.随着盐酸浓度的增加,钛酸盐体系中逐步分离出游离的Ti O6八面体,进而发生Ti O6八面体重组,使水热产物由钛酸盐纳米管转变成二氧化钛纳米片和纳米颗粒.当盐酸浓度为0.55 molL-1时,样品表现出最强的光限幅效应.
The nano-titanate was prepared by alkaline hydrothermal synthesis and the effect of hydrochloric acid post-treatment on the morphology and optical limiting effect of nano-titanate-titania was studied. The samples were characterized by X-ray diffraction analyzer, transmission electron microscopy and scanning electron microscopy The crystal optical properties and nonlinear optical properties of the samples were characterized by UV-Vis and open-cell Z-scan laser techniques.The results showed that when the acid concentration was between 0.10-0.55 molL- 1 range, the hydrothermal product is transformed from titanate to titanate / titania mixture, and the titanate almost completely changes to rutile titania when the acid treatment concentration is higher than 0.78 mol L-1. During the acid treatment, The transformation rate of titanate is directly related to the concentration of hydrochloric acid.With the increase of hydrochloric acid concentration, the free Ti O6 octahedron is gradually separated in the titanate system, and then Ti O6 octahedral recombination occurs, When the concentration of hydrochloric acid was 0.55 mol L-1, the samples exhibited the strongest optical limiting effect.