多面体Fe_(3)O_(4)类芬顿反应去除罗丹明B性能研究

Removal of RhB by Fenton-Like System with Polyhedron Fe_(3)O_(4)

Fe_(3)O_(4)是较典型的n型半导体,被广泛应用于光催化领域,但现阶段制备多面体Fe_(3)O_(4)的步骤比较复杂.本文创新性地采用硫酸亚铁和钼酸钠通过水热法制备磁性多面体Fe_(3)O_(4),与双氧水构建类芬顿体系,以罗丹明B(RhB)模拟污染废水,在可见金卤灯下进行光催化去除RhB实验.采用X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)和磁性能测试等手段对样品进行了充分表征,并探究了不同的pH值、样品浓度、双氧水浓度、RhB初始浓度对RhB去除的影响.结果表明:所制备的样品为结晶度较高的Fe_(3)O_(4)晶体,粒径在300 nm左右;在pH=3、质量浓度为60 mg·L^(-1)、双氧水浓度为100 mmol·L^(-1)、RhB初始质量浓度为20 mg·L^(-1)时,在室温下反应60 min对RhB的去除率可达到94%以上;经反应动力学拟合发现该体系符合一级反应动力学,样品经过4次循环性测试仍具有较高的光催化活性.

Fe_(3)O_(4)is a typical N-type semiconductor,which is widely used in the field of photocatalysis.However,the preparation of Fe_(3)O_(4)at this stage is relatively complicated.The magnetic polyhedral Fe_(3)O_(4)was prepared by hydrothermal method using ferrous sulfate and sodium molybdate,and a Fenton-like system was constructed with hydrogen peroxide.Rhodamine B(RhB)was used to simulate polluted wastewater,and the photocatalytic removal experiment was carried out under visible metal halogen lamp.The samples were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS)and magnetic properties test.The effects of different pH,sample dosage,hydrogen peroxide concentration and RhB initial concentration on RhB removal were investigated.The results showed that the prepared samples were Fe_(3)O_(4)with high crystallinity,and the particle size was about 300nm.The removal rate of RhB could reach more than 94%when pH=3,the dosage was 60 mg·L^(-1),hydrogen peroxide concentration of 100 mmol·L^(-1),and the initial concentration of RhB was 20 mg·L^(-1)at room temperature for 60 min,The reaction kinetics fitting showed that the system accorded with the first-order reaction kinetics,and the sample still had high photocatalytic activity after 4 cycles of testing.