水滑石类化合物-氧化铈催化剂的制备及其光降解甲基橙的性能研究

采用共沉淀法制备了LDHs-CeO2(LDHs为水滑石类化合物)催化剂,并将其用于光催化降解甲基橙溶液,考察了催化剂的原料配比、反应时间、甲基橙初始含量、甲基橙溶液的pH和催化剂用量对甲基橙降解率的影响;同时采用FTIR,XRD,SEM,TEM,EDS,TG等方法对催化剂进行了表征。实验结果表明,n(Mg)∶n(Al)∶n(Ce)=2∶1∶0.50的LDHs-CeO2催化剂活性最高,用该催化剂光催化降解甲基橙溶液的适宜条件为:250 mL甲基橙溶液,甲基橙初始质量浓度40 mg/L,pH=5,反应时间80 min(暗处静置20 min,光照时间60 min),催化剂用量0.3 g;在此条件下,甲基橙降解率达到98.69%。表征结果显示,LDHs-CeO2晶相单一,晶体结构一致,结晶度好,属于六方晶系,形貌为规则的片状结构,分散性较好。

Preparation of Layered Double Hydroxides-CeO2 Catalyst and Degradation of Methyl Orange

Layered double hydroxides-CeO2(LDHs-CeO2) catalysts were prepared by coprecipitation method.Its photocatalytic properties for the degradation of methyl orange solution were tested.The effects of raw material ratio of the catalyst,reaction time,initial methyl orange solution concentration,methyl orange solution pH and catalyst dosage on the degradation were studied.The catalysts were characterized by means of FTIR,XRD,SEM,TEM,EDS and TG.The results showed that the photocatalytic activity of LDHs-CeO2 catalyst with n(Mg)∶n(Al)∶n(Ce) 2∶1∶0.50 in the photocatalytic degradation were the highest.Under the optimal reaction conditions of the initial methyl orange solution concentration 40 mg/L,its pH 5,the reaction time 80 min(dark standing 20 min and then irradiation 60 min) and the catalyst dosage 0.3 g,the methyl orange degradation rate could reach 98.69%.The characterization results revealed that the catalysts were high crystalline with hexagonal system,full layered structure and good dispersity.