铜铝层状双金属氧化物活化过一硫酸盐降解罗丹明B

Degradation of rhodamine B by CuAl-LDO activated persulfate.

摘要:

本研究采用沉淀-煅烧法制备了Cu:Al不同摩尔比的层状双金属氧化物(CuAl-LDO)，用于活化过一硫酸盐(PMS)降解罗丹明B(RhB)。研究了催化剂剂量、PMS剂量、pH、RhB质量浓度、温度和无机阴离子对RhB降解的影响。通过扫描电镜(SEM)、X射线衍射仪(XRD)、傅里叶红外光谱(FTIR)、X射线光电子能谱(XPS)等技术手段进一步表征了样品的性能。结果表明，在投加30 mg/L的CuAl 2:1-LDO和PMS、反应温度为25℃、pH=5.61、RhB质量浓度为100 mg/L的条件下，30 min内的RhB降解率为97.1%。同时，CuAl 2:1-LDO/PMS反应体系在pH值3.00-11.00的较宽范围内,对RhB的降解率具有90%以上，并在第四次循环实验中降解率仍达到71%。其次，电子自旋共振(EPR)、猝灭实验和Uv-vis光谱结果表明,在CuAl 2:1-LDO/PMS体系中产生了较多的硫酸根自由基(SO4-·)和羟基自由基(·OH)，其中·OH在RhB的降解过程中起主导作用，攻击芳香烃环使染料脱色。

Abstract:

layered bimetallic oxides (CuAl LDO) with different molar ratios of Cu: Al were prepared by simple coprecipitation method in this study, which were used to activate persulfate (PMS) to degrade rhodamine B (RhB).The effects of catalyst dosage, PMS dosage, pH value, RhB mass concentration, temperature and inorganic ions on RhB degradation were studied. The properties of the samples were further characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and other technical means.The results showed that under the conditions of adding 30 mg/L CuAl 2:1-LDO and PMS, reaction temperature of 25 ℃, pH=5.61, and RhB mass concentration of 100 mg/L, the RhB degradation rate within 30 min was 97.1%.At the same time, the degradation rate of RhB in CuAl 2:1-LDO/PMS reaction system is more than 90% in the wide range of pH 3.00-11.00, and the degradation rate is still 71% in the fourth cycle experiment.Secondly, the results of electron paramagnetic resonance (EPR) and quenching experiments show that a lot of sulfate radical (SO4-·) and hydroxyl radical (·OH) are produced in CuAl 2:1-LDO/PMS system, in which ·OH plays a leading role in the degradation of RhB, Among them, ·OH plays a leading role in the degradation of RhB, attacking aromatic hydrocarbon ring to decolorize dyes.