目的 利用甲基橙模拟印刷废水，研究SiO2气凝胶/纳米TiO2共混光催化剂对甲基橙的光降解性能。方法 采用溶胶-凝胶法制备SiO2气凝胶，再加入纳米TiO2通过共混法制备出共混光催化剂，利用扫描电子显微镜、X射线衍射仪、傅里叶变换红外光谱分析技术对样品进行表征。使用共混光催化剂降解甲基橙观察其光催化活性。结果 当纳米TiO2和SiO2气凝胶的质量比为1∶4，催化剂质量浓度为0.2 g/L，甲基橙的初始质量浓度为10 mg/L，pH值为4时，甲基橙的降解率最高。结论 利用共混光催化剂降解甲基橙，其光催化效率高，降解率可高达99.85%。

The work aims to study the photodegradation of methyl orange by the blended photocatalyst (SiO2 aerogels/nano-TiO2 composite), with the methyl orange used to simulate the printing wastewater. SiO2 aerogels were prepared in the sol-gel method. Then, the blended photocatalyst was prepared in the blending method with the addition of nano-TiO2. The samples were characterized by SEM, X-ray diffractometer and FT-IR analysis technology. The photocatalytic activity was observed through the degradation of methyl orange with the blended photocatalyst. When the mass ratio of nano-TiO2 and SiO2 aerogels was 1∶4, the mass concentration of catalyst was 0.2 g/L, the initial mass concentration of methyl orange was 10 mg/L and the pH was 4, the degradation rate of methyl orange was the best. The blended photocatalyst is used to degrade the methyl orange. Due to its high catalytic efficiency, the degradation rate can reach as high as 99.85%.