仿生光催化剂的优化制备、介孔特性表征及其在催化降解苯酚废水中的应用

以十二胺(DDA)或十八胺(ODA)为模板剂,采用焙烧或萃洗法去除模板剂制备中孔分子筛(HMS).X射线粉末衍射(XRD)及氮吸附表征结果说明,以十二胺为模板剂且采用焙烧法去除模板剂制备的分子筛具有明显的XRD介孔衍射峰,而且其氮吸附曲线具有典型的IV类等温线特征及H1型脱附滞后环,这属于典型的介孔材料特征.以此分子筛为载体,通过F—C反应将磺酸铁酞菁(FePcS)修饰在HMS上,得到新型光催化剂.催化剂的BET比表面积为675.1m2·g-1,平均孔径为5.78nm,孔容为0.587cm3·g-1,且仍保持着鲜明的介孔特征.最后在模拟可见光照射下应用催化剂处理浓度高达1000mg·L-1的模拟苯酚废水,反应400min后,苯酚的转化率达到85%以上,反应溶液pH值也由4.52降到2.65,表明有酸类降解中间产物生成,反应最终苯酚转化率接近100%,总有机碳(TOC)的去除率达81%以上.催化剂表现出了良好的催化降解有机废水的性能.

Optimizational Preparation and Mesoporous Material Characteristics of a Novel Biomimetic Photocatalyst and Its Application to the Photocatalytic Degradation of Phenol

Hexagonal mesoporous silica (HMS) was synthesized using dodecylamine (DDA) or octadecylamine (ODA) as templates which were then removed by calcination or extraction. Characterization data of HMS from XRD and N₂ adsorption-desorption proved that the optimized material were typical mesoporous materials based on the facts that the XRDdiffraction peak displayed apparently the feature of mesoporous materials and the N₂ adsorption-desorption curve was typical of a type IV isothermand contained a type H1 desorption hysteresis loop. These novel photocatalysts had a BET surface area of 675.1 m²·g^-1, an average pore diameter of 5.78 nm and a BJH pore volume of 0.587 cm³·g^-1, and were prepared by the F—C reaction between functionalized HMS and iron sulfophthalocyanine (FePcS). Additionally, the catalysts preserved an undamaged heavy mesoporous structure. Upon the irradiation of the simulated visible light, these novel catalysts were applied to the degradation of simulated phenol wastewater at a concentration of 1000 mg·L^-1. The conversion of phenol reached 85%and the pH decreased from the original 4.52 to 2.65 after reaction time of 400 min, which indicated that acid intermediates were produced during the photocatalysis of phenol. Finally, the conversion rate of phenol was nearly 100% and the total organic carbon (TOC) removal rate exceeded 81%. The novel catalyst is, therefore, highly effective for the degradation of phenol.