TiO2/(O'+β')-Sialon是一全新的复相陶瓷体系。在对其化学相客性进行研究的基础上,以自制(O'+β')-Sialon粉和纳米锐钛矿型TiO2粉为原料成功制备出了该复相陶瓷,并以其对亚甲基蓝溶液的降解为模型反应对其光催化性能进行了研究。热力学计算表明,标态下,β’-Sialon在任何温度、O’-Sialon在690K以上均可与TiO2发生反应。实验结果表明,O’-Sialon和β’-Sialon与TiO2发生反应的温度在1000℃以上,锐钛矿从920℃开始发生向金红石的相变,通过在不高于1000℃温度下改变烧结制度得到了亚稳态的不同TiO2相组成的TiO2/(O'+β')-Sialon复相陶瓷。该复相陶瓷具有光催化活性,且光催化效率随材料中TiO2含量的增加而增大。800和900℃烧结的材料具有较高的光催化活性,随烧结温度的升高和恒温时间的延长材料的光催化活性逐渐下降。
TiO2/(O'+β')-Sialon, a new multi-phase ceramics, were successfully prepared on the basis of chemical-compatibility study on the system with home-made (O'-β’)-Sialon powder and nano anatase powder as raw materials. Photocatalytic activity of TiO2/(O'+β')-Sialon multiphase ceramics was investigated through its photoeatalytie degradation to methylene blue (MB) solution. Thermodynamic calculation indicates that β’-Sialon and O’-Sialon react with TiO2 at any temperatures and above 690K in static status, respectively. The experiment results show that in actual sintering conditions, both the two reactions took place above 1000℃, while the phase transformation from anatase to ruffle occurred above 920℃. Metastable-state TiO2/(O'+β')-Sialon composites with various phase composition of TiO2 were obtained by sintering at various sintering rules not higher than 1000℃, TiO2/(O'+β')-Sialon multiphase ceramics exhibit photocatalytic activity and the photocatalytic degradation rate of MB increases with the increase of TiO2 content and decreases with the increase of sintering temperature and holding time. Relatively high photocatalytie activity was obtained for the materials sintered at 800 and 900℃.