| Because there are 18 conjugated electrons in the porphyrin ring and there are conjugated double bonds,they can transmit electrons or excite electrons under ultraviolet and visible light irradiation.Its photosensitivity is high and it can degrade pollutants under light.The polyoxometalate has a structure similar to that of a semiconductor and has a distinct absorption peak in the ultraviolet to visible region.Under UV light conditions,active free radicals can be generated to achieve the purpose of degrading organic pollutants.In this paper,three new ionic tetranitrophenylporphyrin-Anderson polyoxo organic and inorganic compounds were synthesized by the reaction of tetranitrophenyl porphyrin with Anderson polyoxometalate and keggin polyoxometalate respectively.The compounds and three new ionic tetranitrophenylporphyrin-Keggin polyacid organo-inorganic hybrids have been systematically characterized.Afterwards,the photocatalytic degradation of 1.5-dihydroxynaphthalene based on Anderson-type polyacid hybrids as photocatalysts was studied systematically.Photocatalytic oxidation of sulphur-containing compounds in simulated oils based on Keggin-type polyacid hybrids as photocatalysts was studied.Desulfurization performance.The main results achieved in this paper are as follows:1.1.Select photo-sensitive tetranitrophenylporphyrin(C44H26N8O8,denoted as TNPP)and Anderson-type polyoxometallate[N(C4H9)4]2{H2ZnMo6O18[(OCH2)3CNH2]2} Is ZnMo6),[N(C4H9)4]2{MnMO6O18[(OCH2)3CNH2]2}(denoted as MnMO6),[N(C4H9)4]3{FeMo6O18[(OCH2)3CNH2]2}(denoted as FeMo6 The role of the successful synthesis of three ionic hybrids(H2TNPP){H2ZnMo6O18[(OCH2)3CNH2]2}(referred to as TNPP-ZnMo6),(H2TNPP)1.5{MnMo6O18[(OCH2)3CNH2]2}(TNPP-MnMo6),(H2TNPP)1.5{FeMo6O18[(OCH2)3CNH2]2}(referred to as TNPP-FeMo6),passed FT-IR,UV-vis,1H NMR,elemental analysis,Jobs curve,cyclic voltammetry,etc.Characterize its composition and structure.The newly synthesized three kinds of hybrids were studied.(H2TPP){H2ZnMo6O18[(OCH2)3CNH2]2}(reported as TPP-ZnMo6),(H2TPP)1.5{MnMo6O18[(OCH2)3CNH2]2} reported by our group,(reported as TPP-MnMo6),(H2TPP)1.5 {F eMo6018[(OCH2)3CNH2]2}(referred to as TPP-FeMo6),and raw material polyacid and raw material porphyrin photocatalytic degradation of 1.5-dihydroxynaphthalene,the results It shows that the photocatalytic degradation of 1.5-dihydroxynaphthalene by TPP-ZnMo6 is best under visible light conditions.When the amount of TPP-ZnMo6 catalyst was 4 mg and the reaction temperature was 35?,the degradation rate of DHN by TPP-ZnMo6 reached 100%within 8 minutes.The catalyst TPP-ZnMo6 showed no significant decrease in the degradation rate of DHN after 10 consecutive photocatalytic reactions,indicating that the catalyst has good reusability.This is due to the introduction of polyoxometalates in the porphyrin system.Under visible light irradiation,energy levels transition between porphyrins and polyacids,transferring energy to oxygen,increasing the amount of singlet oxygen generated,and accelerating the catalytic reaction.2.Choose photosensitivity of tetranitrophenylporphyrin(C44H26N8O8,denoted as TNPP)and Keggin type polyoxometallate H3PW12O40·xH2O(PW12),H3PMo12O40·xH2O(PMo12),H4SiMo12O40·xH2O(SiMo12)Three kinds of ionic hybrids(H2TNPP)(HPW12O40)·2C4H8O·2H2O(referred to as TNPP-PW12)?(H2TNPP)(HPMo12O40)·5C4H8O·5H2O(referred to as TNPP-PMo12)?(H2TNPP)(H2SiMo12O40)·3C4H8O·3H2O(referred to as TNPP-SiMo12).The composition and structure of the composite were characterized by FT-IR,UV-vis,elemental analysis,and spectral titration.The newly synthesized three kinds of hybrids were studied.Our group's(H2TPP)(HPW12O40)·2C4H8O·2H2O(reported as TPP-PW12),(H2TPP)(HPMo12O40)·5C4H8O·5H2O(reported as TPP-PMo12)(H2TPP)(HSiMo12O40)·3C4H8O·3H2O(reported as TPP-SiMo12)and raw materials were investigated.The results show that TPP-PW12 has the best catalytic oxidation desulfurization performance.Under the conditions of 500W mercury lamp,the amount of TPP-PW12 catalyst used was 30mg,the amount of H2O2 was 0.3ml,DBT with 500ppm sulfur content was completely degraded in 18min,and BT was completely degraded in 45min reaction.After 10 cycles of the catalyst TPP-PW12,the photocatalytic oxidation desulfurization effect is still above 93%.This may be due to the formation of an electron donor-acceptor system between the porphyrin and the polyacid,which synergistically under the light conditions to generate active radicals·OH and O2-,and accelerate the catalytic reaction. |
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