Design And Synthesis Of Boron-containing Conjugated Microporous Polymers And Their Photocatalytic Performance

Converting solar energy into chemical energy is an effective way to solve the energy crisis and environmental pollution facing the world today.Boron-containing fluorescent dyes have become more potential photocatalysts due to their wide light absorption range and structural designability.It also has the disadvantages of high cost,cumbersome separation steps,and easy photobleaching.Organic porous polymers have clear porosity,adjustable structure,and excellent chemical stability.In this paper,organic porous polymerization and boron-containing fluorescent dyes are combined to obtain several heterogeneous conjugated microporous polymer photocatalysts based on boron-containing fluorescent dyes,and their photocatalytic properties are further studied.The main contents include:(1)Study on the construction and photocatalytic performance of boron-containing conjugated microporous polymers based on Sonogashira coupling reaction.With the boron-containing fluorescent dye Boranil as the core component,a new type of boron-containing conjugated microporous polymer TDFB-TEB was synthesized by Sonogashira coupling reaction.To prove the important role of boron-containing dyes in the material,a conjugated microporous polymer without boron coordination(TCT-TEB)was further synthesized as a reference.The structure,pore properties and thermal stability of the two polymers were characterized by infrared,¹³C NMR,XPS,BET,SEM,thermogravimetry and XRD;the photoelectric properties of the polymers were tested by solid ultraviolet,Mott-Schottky curve,photo-generated current and EPR.Further photocatalytic performance studies show that TDFB-TEB has good catalytic performance for the oxidation of sulfides and the coupling of benzylamine in the two model reactions,and the effect is significantly better than that of TCT-TEB,which shows that boron-containing dyes play an important role in the photocatalytic reaction process,and TDFB-TEB has good universality,good cycling and stability.(2)Research on Boranil-based D-A conjugated microporous polymer and its photocatalytic performance.The good D-A effect in the material structure can effectively enhance the photocatalytic effect.Firstly,the Boranil monomer substituted with carbazole with electron donating effect was designed and synthesized,and then the polymer p CZFB with D-A effect was obtained through the oxidative coupling polymerization strategy.The polymer structure,pore properties and thermal stability were characterized by infrared,BET,SEM,thermogravimetric and X-ray powder diffraction;the photoelectric properties of the polymer were tested by solid ultraviolet and Mott-Schottky curve.The photocatalytic performance of polymer p CZFB was tested with the ring-closing condensation reaction of benzimidazole and the oxidation reaction of sulfide as model reactions.The results show that:compared with the reported literature,p CZFB has excellent photocatalytic performance,especially in the use of relatively environmentally friendly solvent system,it can still show good conversion efficiency and universality for the two models.Finally,we also discussed the mechanism of the two model reactions separately.