• 关键词：二氧化钛  二氧化硅  气凝胶  光催化剂  2,4-二硝基酚

• 基金项目：国家自然科学基金(No. 20977013)

• 梁文珍
• 大连理工大学化学学院,大连 116023

• 王慧龙
• 大连理工大学化学学院,大连 116023

• 姜文凤
• 大连理工大学化学学院,大连 116023

• 摘要：以正硅酸乙酯(TEOS)为原料,采用溶胶-凝胶法(sol-gel)和常压干燥法制备SiO₂气凝胶,在此基础上,将硅气凝胶掺杂进入TiO₂溶胶中制备出TiO₂/SiO₂气凝胶复合光催化剂.利用XRD、TEM和FI-IR等技术对其晶型、形貌和结构进行表征,研究了太阳光下TiO₂/SiO₂气凝胶复合光催化剂对2,4-二硝基苯酚(DNP)的光催化降解性能.结果表明,500℃焙烧后的TiO₂/SiO₂气凝胶复合材料对DNP溶液的吸附率和光降解率明显优于纯TiO₂样品,加入7.5%(质量分数)SiO₂气凝胶的复合光催化剂表现出最佳的光催化活性.根据Langmuir-Hinshelwood方程,在低浓度下光催化降解DNP的反应符合一级反应动力学.

• Abstract：Silica aerogels were synthesized by sol-gel technique at ambient pressure using tetraethyl orthosilioate. The TiO₂/silica aerogel composite photocatalysts were prepared by doping silica aerogel into the nanosized TiO₂ particles. The microstructure and morphology of the photocatalysts were characterized by XRD, TEM and FT-IR techniques. The photocatalytic degradation of 2,4-dinitrophenol (DNP) was investigated by using this novel TiO₂/silica aerogel composite photocatalyst under solar light irradiation. The results showed that the highest photocatalytic activity was obtained when the composite sample was calcined at 500℃ with an optimal silica aerogel content of 7.5%(wt.). Compared to the pure TiO₂ catalyst, the TiO₂/silica aerogel composite photocatalyst showed much higher adsorption capacity and photocatalytic degradation efficiency for DNP. The photocatalytic reaction is discussed in terms of Langmuir-Hinshelwood model and it followed pseudo-first order kinetics at low concentration.

• Key words：titania  silica  aerogel  photocatalyst  2,4-dinitrophenol

• 
  摘要点击次数： 2687 全文下载次数： 4390