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.
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.
出处
《环境科学学报》
CAS
CSCD
北大核心
2011年第6期1162-1167,共6页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.20977013)~~
