花状软锰矿的超声合成及其对亚甲基蓝的脱色性能

Ultrasonic synthesis of flower-like manganese wads and its decolorization performance for methylene blue

首次通过操作简便成本低廉的超声方法合成花状软锰矿(MWs).采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)以及能量散布分析仪(EDS)等测试手段对其结构和形貌进行表征.研究了MWs对偶氮染料亚甲基蓝(MB)的脱色性能,考察pH值、反应时间、MWs投加量以及MB初始浓度等影响因子对脱色效果影响.结果表明,MWs对MB具有优良的脱色性能,90min达到近100%的脱色率,无需使用H2O2或者UV灯和超声等其它辅助设备,这明显优于其他催化剂,如Mn3O4/H2O2需3h达到99.7%最大脱色率、ZnS/CdS在光照下需6h最大脱色率仅为73%、硫改性的TiO2光照下需4h才能达到近100%的脱色率.

Flower-like manganese wads（MWs） was synthesized via a simple and inexpensive ultrasonic method for the first time. The structure and morphology of MWs were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM） and energy dispersive spectrometer（EDS）. The decolorization efficiencies of MWs for azo dye methylene blue（MB） were examined as a function of solution pH, stirring time, MWs dosage, and initial MB concentration. Results showed that MWs had higher decolorization efficiency（the maximum decolorization rate of nearly 100% in 90min） than other catalysts, such as Mn3O4/H2O2（the maximum decolorization rate of 99.7% in 3h）, ZnS/CdS（the maximum decolorization rate of 73% in 6h under light irradiation）, and sulfate modified titania（the maximum decolorization rate of nearly 100% in 4h under solar radiation）. Most importantly, MWs alone can effectively remove MB from the solution without using H2O2or other special devises such as UV light and ultrasonic equipment.