CuAl-LDO活化过一硫酸盐降解罗丹明B

Degradation of Rhodamine B by CuAl-LDO activated peroxymonosulfate

采用沉淀-煅烧法制备了Cu/Al不同物质的量比的层状双金属氧化物(CuAl x-LDO,x为Cu与Al的物质的量比),用于活化过一硫酸盐(PMS)去除罗丹明B(Rh B)。考察了催化剂用量、PMS用量、pH、RhB质量浓度、温度和无机阴离子对RhB去除率的影响。通过SEM、XRD、FTIR、XPS和BET测定与表征了CuAl x-LDO的结构与性能。结果表明,在投加量均为300 mg/L的CuAl 2:1-LDO和PMS、反应温度为25℃、pH=5.6、Rh B质量浓度为100mg/L的条件下,30min内Rh B的去除率为97.1%。同时,CuAl2:1-LDO/PMS反应体系在pH为3.0~11.0的较宽范围内,对Rh B的去除率达90%以上,并且催化剂第4次使用时Rh B去除率仍达71.0%。另外,电子顺磁共振(EPR)、猝灭实验和UV-Vis光谱结果表明,在CuAl2:1-LDO/PMS体系中产生了较多的硫酸根自由基(SO_(4)^(-)·)和羟基自由基(·OH),其中·OH在RhB的去除过程中起主导作用,作用于芳香环使染料脱色。

Layered double metallic oxides with different Cu/Al molar ratios(CuAl x-LDO,x being the molar ratio of Cu to Al),synthesized via precipitation calcination method,was used to activate peroxymonosulfate(PMS)for the removal of Rhodamine B(RhB).The effects of catalyst dosage,PMS dosage,pH,RhB mass concentration,temperature and inorganic anions on removal rate of RhB were investigated.The structure and properties of CuAl x-LDO were characterized by SEM,XRD,FTIR,XPS,and BET.The results showed that under the conditions of CuAl 2:1-LDO,PMS dosage of 300 mg/L,reaction temperature of 25℃,pH=5.6,and RhB mass concentration of 100 mg/L,the RhB removal rate within 30 min reached 97.1%.At the same time,the CuAl 2:1-LDO/PMS reaction system displayed a removal rate of over 90%for RhB in a wide range of pH 3.0~11.0,with the removal rate maintained 71.0%in the fourth cycle experiment.In addition,data from electron paramagnetic resonance(EPR),quenching experiments,and UV-Vis spectroscopy indicated that more sulfate radicals(SO_(4)^(-)•)and hydroxyl radicals(·OH)were generated in the CuAl 2:1-LDO/PMS system,and·OH played a leading role in the removal of RhB,acting on the aromatic hydrocarbon ring to decolorize the dye.