Ag6Si2O7/TiO2 复合光催化剂的制备及其对亚甲基蓝的降解性能

为制备具有稳定性能的可见光催化剂,采用原位沉积法制得Ag₆Si₂O₇/TiO₂复合可见光催化剂。对光催化剂的表面形貌、结晶结构、化学元素组成和荧光光谱进行分析。在可见光照射下,以亚甲基蓝为有机污染物模型,探讨了TiO₂质量分数对复合光催化剂光催化降解效率的影响。结果表明:Ag₆Si₂O₇/TiO₂复合光催化剂中,Ag₆Si₂O₇均匀地包覆在TiO₂表面,二者以核壳结构形式紧密结合,且Ag、Si和Ti是以Ag⁺、Si⁴⁺和Ti⁴⁺存在;与纯Ag₆Si₂O₇和纯TiO₂相比,Ag₆Si₂O₇/TiO₂光催化剂具有更高的可见光光催化活性;当TiO₂质量分数为20%时,对亚甲基蓝降解效果最佳,在20 min内降解率达到98.6%。这种新型高效复合可见光催化剂可用于处理印染废水,具有广阔的应用前景。

Preparation of Ag6Si2O7/TiO2photocatalyst and its photocatalytic degradation of methylene blue

In order to prepare visible light catalyst with stable performance,a novel highly efficient Ag₆Si₂O₇/TiO₂photocatalyst was prepared by an in-situ deposition method.The surface morphology,crystalline structure,chemical elemental composition and fluorescence spectrum of the photocatalyst were analyzed.The photocatalytic activity of the composite catalyst with different concentration of TiO₂were tested by degrading methylene blue(MB)under simulated visible light at room temperature.The results show that Ag₆Si₂O₇are coated on TiO₂uniformly,Ag₆Si₂O₇and TiO₂are tightly bonded in the form of core-shell structure,and Ag⁺,Si⁴⁺and Ti⁴⁺exist in composite catalyst.The results of photocatalytic degradation of MB show that the Ag₆Si₂O₇/TiO₂photocatalyst exhibits higher photocatalytic activity under visible light than Ag₆Si₂O₇and TiO₂used separately.When the mass fraction of TiO₂is 20%,the photocatalyst possesses the highest photocatalytic activity.The degradation efficiency for MB is up to 98.6%after irradiating in simulated solar for 20 min.The novel high-efficiency Ag₆Si₂O₇/TiO₂photocatalyst has a broad application prospect in treatment of printing and dyeing wastewater.