Perovskite-like Catalyst And Its Degradation Of Rhodamine B By Activated Persulfate

Rhodamine B?Rh B?has become a hot topic in the field of water pollution control at home and abroad,due to carcinogenicity,mutagenicity and cardiotoxicity for the treatment of Rh B wastewater.In this research,the degradation of Rh B has been researched via perovskite-like catalysis combined with peroxymonosulfate?PMS?.The research contents and results are shown as follows:1.LaTi_xO₃?x=0.1,0.2,0.4,0.6?catalysts,abbreviated as LCT_x,were prepared by the sol gel method and characterized by X-ray diffractometer?XRD?,Scanning electron microscope?SEM?and X-ray photoelectron spectroscopy?XPS?.The results indicated that LCT_0.4 exhibited the highest degradation efficiency of89.1%for removal Rh B.The addition of PMS generated sulfate radical?SO₄·^-?in the reaction process,which greatly improved the catalytic activity of Rh B over LCT_0.4catalyst,and La Co_0.6Ti_0.4O₃ showed the most effective catalyst for Rh B degradation under dark conditions.2.Sr BO_3-x?B=Fe,Co,Mn?catalysts,abbreviated as SBO,were prepared by sol gel method,and characterized by Energy dispersive spectrometer?EDS?,High resolution transmission electron microscopy?HRTEM?,Selective electron diffraction?SAED?,N₂ adsorption and desorption,XRD,ESR,XPS,SEM,Thermogravimetric analysis?TGA?,and Fourier transform infrared spectroscopy?FT-IR?.Series of SCO perovskite catalysts containing strontium and cobalt metal were prepared.The catalytic properties of the catalysts under different preparation methods?a?and different conditions?b??labeled as SCOa-b?were investigated.For example,4 represented sol-gel method and 8 means that p H of 2,PMS concentration of 0.14 g,and catalyst dose of 0.03 g in the SCO4-8 catalyst.Meanwhile,the catalyst showed a good performance with 99.4%efficiency for Rh B degradation,which mainly exists in the form of Sr Co O_2.5.Degradation Rh B efficiency of SCO4-8 almost recovers during 7 cycles at 500°C calcination temperature for 1 h,which may be the decomposition of pollution adsorbed on the surface of the catalyst.The active species contribute as follows:¹O₂>SO₄·^-.Therefore,there was a synergistic effect between PMS and SCO4-8,which produced¹O₂,This catalyst is the most efficient for Rh B degradation under PMS and no light conditions.3.The composite catalysts,abbreviated as LCT_0.4/SCO3,were fabricated by combining the multi-metal oxides?lanthanum,cobalt and titanium?with perovskite including strontium and cobalt metal,which were prepared by sol-gel method and marked as No.3.The influence of compound on catalyst performance was investigated by XRD,SEM,XPS,Ultraviolet-visible diffusion reflectance spectrum?UV-Vis?and Electron spin resonance?ESR?.The result indicates that the composite did not significantly improve the catalytic activity.With the addition of PMS,catalysts exhibited 89.2%efficiency for Rh B degradation,which was 4.1 times than that of without PMS.The active species for Rh B degradation was in the order of SO₄·^->·OH.SO₄·^-was considered to be the most active species as the active species in the catalyst system.4.Sr₂Fe Co O₆?SFCO?,La Co O₃?LCO?,Ca Si O₃?CSOn?n=1,2??with hydrothermal spherical or rhombic,Ba Sn O₃?BSO?,perovskite including strontium cobalt catalyst?SCOa,a=1-7?,and perovskite containing lanthanum,cobalt and titanium catalyst(LCT_0.4-a,a=1-17)were prepared by coprecipitation.In the ultraviolet?UV?/Rh B system,the influence factors of catalyst performance were investigated.Degradation efficiency of SFCO reached 96.4%in 11 min at 6 of p H,and the active species were in the order of SO₄·^->¹O₂.Under the condition of LCT_0.4-16/UV and without PMS,the removal rate of Rh B reached 76.9%at 12 min.Therefore,LCT_0.4-16 catalyst is the most efficient catalyst for Rh B degradation under UV light conditions and without PMS.