基于水滑石的Zn-Cr-Cu复合金属氧化物的制备及其对罗丹明B的光催化降解性能

Synthesis and Photocatalytic Degradation Performance for Rhodamin B of Zn-Cr-Cu Composite Metal Oxides Derived from Layered Double Hydroxides

采用共沉淀法一步组装获得席夫碱铜(Ⅱ)插层的Zn-Cr水滑石(ZnCr-SBCu-LDHs),再经500℃高温焙烧制得新颖的Zn-CrCu复合金属氧化物(ZnCr-SBCu-LDO)光催化材料。通过X射线粉末衍射(XRD)、紫外-可见漫反射图谱(UV-Vis DRS)、扫描电子显微镜(SEM)、电感耦合等离子体原子发射光谱(ICP-AES)对催化材料的结构和性质进行分析表征。以较难被水滑石吸附的阳离子型染料罗丹明B(RhB)作为模型,研究材料的光催化活性,考察材料用量、RhB溶液的初始pH值、温度以及H_2O_2初始浓度等对光催化活性的影响。结果发现:ZnCr-SBCu-LDO具有优异的光催化活性,在初始pH值为7.40、温度为25℃以及H_2O_2初始浓度10 mmol·L^(-1)的条件下,光照4 h后,1 g·L^(-1)的催化材料对5 mg·L^(-1)的RhB溶液的降解效率可达98.68%。此外,进一步对催化剂的再生能力进行了研究,并初步探讨了光催化降解的机理。

Novel complexes of Copper(Ⅱ)with Schiff-base intercalated zinc-chromium layered double hydroxides(ZnCr-SBCu-LDHs)were successfully prepared via coprecipitation.Zn-Cr-Cu composite metal oxides(ZnCr-SBCu-LDO)as an original photocatalytic material was derived from ZnCr-SBCu-LDHs after calcination at 500℃.The structure and properties of the photocatalytic materials were thoroughly characterized by powder X-ray diffraction(XRD),ultraviolet visible diffuse reflectance spectroscopy(UV-Vis DRS),scanning electron microscopy(SEM)and inductively coupled plasma-atomic emission spectrometry(ICP-AES).The activities of the photocata-lytic materials were investigated by photodegradation of cationic dye rhodamin B(RhB)which was hard to adsorb by LDHs.The effects of initial photocatalyst amount,initial pH,temperature of RhB solution and initial concentration of H2O2 on the photocatalytic efficiency were discussed.The results show that ZnCr-SBCu-LDO display higher photocatalytic activity for RhB degradation.The degradation efficiency of RhB solution(5 mg·L^-1)with ZnCr-SBCu-LDO(1 g·L^-1)reached 98.68%after 4 h irradiation,when the temperature was 25℃,the initial pH value was 7.40 and the initial concentration of H2O2 was 10 mmol·L^-1.In addition,the regeneration of the catalyst was studied and the mechanism of photocatalysis was preliminarily discussed.