Fe(Ⅲ)-taPc/ZnONWs/SiO_2三元复合光催化剂的制备和性能

Preparation and Photocatalytic Degradation Properties of a Fe(Ⅲ)-taPc/ZnO NWs/SiO_2 Ternary Composite Photo-catalyst

采用晶种原位形成与水热合成法,在SiO2大孔材料中原位生长出氧化锌纳米线(ZnO NWs)。纳米线是由六方纤锌矿型氧化锌晶体构成,在孔道内呈现无规纳米线团形貌,且分散良好、结构稳定,其直径为15-20 nm。ZnO NWs/SiO2复合能有效负载四羧基酞菁铁(Fe(Ⅲ)-taPc),最高负载量(质量分数)为11.5%。进一步制备出Fe(Ⅲ)-taPc/ZnO NWs/SiO2三元复合光催化剂,通过扫描电镜(SEM)、粉末衍射(XRD)、紫外-可见漫反射光谱(UV-Vis)、Raman光谱(Raman)对其进行表征,并以有机染料罗丹明B为目标降解物考察了其可见光光催化降解性能。结果表明,在可见光照射下三元催化剂能快速催化降解罗丹明B,降解反应遵守一级动力学方程。Fe(Ⅲ)-taPc负载量(质量分数)为3.5%的三元复合光催化剂显示出最高的活性,在60 min内使罗丹明B的降解率达到98.6%,ZnO NWs的存在使Fe(Ⅲ)-taPc的光催化活性平均提高77%。6次循环使用后三元复合催化剂的活性没有明显下降,表明催化剂性能稳定,可重复使用多次。

ZnO nanowires were prepared by crystal seed formation in situ and hydrothermal synthetic process in large-sized macroporous SiO2 materials. The nanowires are formed by wurtzite ZnO crystal with a diameter of about 15-20 nm, which display a randomly-coiled morphology, good dispersion as well as stable structure. ZnO NWs/SiO2 complex can effectively load Fe （III）-taPc to offer ternary compos- ite photo-catalyst Fe（III）-taPc/ZnO NWs/SiO2 with a maximum loading rate（mass fraction） of 11.5%. The photo-catalyst Fe（III）-taPc/ZnO NWs/SiO2 was characterized by means of SEM, XRD, UV-Vis diffuse reflectance spectrometry and Raman spectrometry. The photocatalytic activity of the photocatalysts was also determined by using Rhodamine B as the objective substance. The catalyst exhibited good activity for the degradation of Rhodamine B under visible light, and the reaction followed first-order kinetic equation. The catalyst containing 3.5% of Fe（III）-taPc showed highest activity, and can degrade 98.6% of Rhodamine B within 60 min. The presence of ZnO NWs promoted the photocatalytic activity by an average of 77%. The activity decreased very slightly after six circular utilizations, showing that the catalyst was stable and reusable.