太阳光/CuMnFe LDHs催化剂/过一硫酸盐体系降解双酚A

利用水热法合成了具有高催化活性的CuMnFe三元金属氢氧化物(LDHs)催化剂,确定了最佳的Cu、Mn、Fe摩尔比,通过XRD、XPS、UV-vis DRS、FT-IR、SEM、TEM、BET等方法对催化剂进行了表征,并探究了催化剂投加量、PMS浓度、溶液pH、阴离子的种类和浓度对体系BPA去除的影响,进而通过LC-M...

Degradation of bisphenol A using CuMnFe LDHs catalyst and peroxymonosulfate under solar light

The CuMnFe layered trimetallic hydroxides (LDHs) catalyst with high catalytic activity was synthesized by the hydrothermal method, and the optimal molar ratio of Cu, Mn and Fe was determined. XRD, XPS, UV-vis DRS, FT-IR, SEM, TEM and BET were used to characterize the LDHs, and the effects of catalyst dosage, PMS concentration, initial pH, the type and concentration of anions on the degradation of bisphenol A were studied. LC-MS was also used to identify the degradation products and pathways. The results showed that the highest crystallinity of LDHs occurred when the molar ratio of Fe was 0.29, and the strongest light utilization efficiency and catalytic activity occurred when the molar ratio of Cu∶Mn was 1∶1. Under the simulated solar light irradiation, the removal rate for 20mg.L−1 BPA was 93.5% after 15 min oxidation at the optimized 0.6 g·L−1 1∶1 Cu/Mn-Fe LDHs (1∶1 CMF) and 0.4 mmol·L−1 PMS. 1∶1 Cu/Mn-Fe LDHs had a good stability and reusability. Within pH 3~11 of raw solution, LDHs maintained a good catalysis performance, which would decrease at acidic conditions of pH 3~5, and the removal rate of BPA was 79.3%. Cl− accelerated the degradation of BPA, while H2PO4−, NO3− and HCO3− inhibited the reaction. In addition, the effects of anions concentrations on BPA degradation by this system was analyzed, and the relative contributions of different active species were also discussed. Superoxide radicals (O2·−) and holes (h+) were the most important active components in this reaction system. PMS withdrew free electrons and greatly promoted the production of h+, while the transition metal elements of LDHs could interact with PMS to generate stable intermediates, which withdrew the electron from other PMS to generate O2·−.