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釆用十六烷基三甲基溴化铵为模板剂,钛酸四丁酯为钛源、正硅酸乙酯为硅源,硝酸铬为金属前驱体,通过一步法制备了吸附性能优异且具有紫外-可见光催化活性的Ti-Cr-MCM-48钛硅分子筛催化剂.通过XRD、FT-IR、SEM、BET、UV-Vis等分析手段对产物进行结构表征并研究了样品对罗丹明B的吸附以及光催化性能,同时探究了钛含量对分子筛结构与性能的影响.结果表明,当钛含量为n(Ti)/n(Si)=0.25时,钛和铬分散在分子筛骨架上,样品0.25Ti-Cr-MCM-48依然具有大比表面积和介孔结构,成功解决了过渡金属掺杂而造成比表面积下降的难题.同时样品0.25Ti-Cr-MCM-48展现出了优异的吸附和催化性能,3 h内对罗丹明B的吸附、降解效率达到85%以上.而当钛含量进一步提高时,分子筛的立方相结构被破坏,孔道结构堵塞严重,比表面积急剧下降,吸附性能下降.

Ti-Cr-MCM-48 photocatalyst was successfully synthesized via a facile and rapid single-step approach at room temperature, which takes CTAB as a template, Cr(NO3)3·9H2O and titanium isopropoxide as metallic precursors and TEOS as source of silicon.The resulting samples were characterized by XRD, FT-IR, SEM, BET and UV-Vis.The photocatalytic activities of the resulting samples were compared by removing RhB under UV and visible light irradiation.The effect of Ti content on the structure and performance of molecular sieve has also been studied, which shows that Ti and Cr can be evenly dispersed on the molecular sieve skeleton at the ratio of n(Ti)/n(Si) is 0.25.The sample 0.25Ti-Cr-MCM-48 has large specific surface area and mesoporous structure, which successfully solves the issue that the specific surface area decreased due to the doping of transition metal.The sample 0.25Ti-Cr-MCM-48 shows excellent adsorption and photocatalytic performance of Rhodamine B, which efficiency reached up to 85% in 3 h.When Ti content is further improved, the cubic phase structure of the molecular sieve are destroyed and the specific surface area has decreased sharply, which leads to the adsorption performance decrease.