| Microporous organic polymer has high surface area,low skeleton density and special pore structure.Functional modification for microporous organic polymer can provide more excellent properties,which can further expand the application of materials.At the same time,the microporous organic polymer has a relatively stable organic skeleton structure and good chemical and thermal stability,the researchers regard the microporous organic polymer as an ideal heterogeneous catalyst carrier material,which can be used to load metal or metal oxides nanoparticles with catalytic properties.In this paper,a novel carboxyl-functionalized hollow microporous organic nanospheres framework was prepared by the strategy of hyper-cross-linking mediated self-assembly with the triblock copolymer ploylactide-polytertbutyl acrylate-ploystyrene?PLA-b-PtBA-b-PS?as the precursor.Hollow microporous organic nanospheres composite supported by silver nanoparticles were successfully prepared by further ion exchange and in-situ reduction of sodium borohydride.Due to the special structure and properties of the prepared materials(the BET surface area is about 430 m2 g-1),the active sites of silver nanoparticles are uniformly and stably dispersed in the cavity?the size of Ag nanoparticles is about 7 nm?,thereby improving the activity to the corresponding catalytic reaction.According to the quasi first order kinetic analysis,the catalytic reduction rate of methylene blue is 1.47×10-2 s-1,and the TOF value is 3.2×10-22 min-1;the catalytic reduction rate of p-nitrophenol is1.17×10-2 s-1 and the TOF value is 0.58 min-1;the yield of selective catalytic oxidation of mercaptan is 96%,and the TOF value is 100 min-1;the selectivity of selective catalytic oxidation of styrene is as high as 92%.After 10 cycles,the prepared silver catalyst also has stable structure and catalytic performance.Using the biblock copolymer ploylactide-ploystyrene?PLA-b-PS?and benzylamine monomer as the precursor,a new type of hollow microporous organic nanospheres with Schiff base structure was prepared by the blending hyper-cross-linking mediated self-assembly and the post-synthesis modification reaction of amino group and salicylaldehyde.Then,the hollow microporous organic nanospheres supported copper complex catalyst was successfully synthesized with the coordination of Schiff base and copper ion.The prepared copper complex catalyst has good multi-stage pore distribution?micropores/mesopores?,high surface area(the BET surface area is about476 m2 g-1)and uniformly distributed active sites.In the selective epoxidation of olefins,the selectivity is 84%,the yield is 96%and the TOF value is 200 h-1.After 12cycles,the structure is still maintained.The hollow microporous organic nanospheres supported with Fe0 nanoparticles,which possess unique yolk-shell structures?YS-Fe@HPNFs?were successfully prepared by the method of hyper-cross-linking mediated self-assembly and impregnation reduction with the ploylactide-ploystyrene biblock copolymer as the precursor.The prepared catalyst YS-Fe@HPNFs has high surface area(the BET surface area is about 416 m2 g-1),multi-stage pore distribution and unique yolk-shell nanostructure,the degradation rate of methyl orange dye is over 97%.Subsequently,the effects of different catalyst dosage,pH value and initial concentration of methyl orange on the catalytic degradation of methyl orange by YS-Fe@HPNFs also has been explored.The results showed that the acid condition?pH=3?is beneficial to the degradation of methyl orange dye.The hollow microporous organic nanospheres framework with ultra-small cuprous oxide nanoparticles?Cu2O@HPNFs?were successfully prepared by the combination of the one-step precipitation and the hyper-cross-linking mediated self-assembly strategy using ploylactide-ploystyrene diblock copolymer as the precursor.Owing to the ultrasmall-size of Cu2O nanoparticles and the high surface area(the BET surface area is about 404 m2 g-1)and micro/mesoporous structure of HPNFs,the catalytic reduction rate of the prepared Cu2O@HPNFs for 4-nitrophenol?4-NP?was 3.3×10-2s-1 and the photocatalytic degradation rate for methyl orange was 2 mg min-1 g-1.After repeated circulation for 10 times,Cu2O@HPNFs still has stable structure and catalytic performance. |
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