Preparation And Properties Of Organic Conjugated Semiconductor Materials Based On Carbazole Unit

Conjugated polymer semiconductor materials not only have the electrochemical and optical properties of metals and semiconductors,but also retain the mechanical properties and processing properties of traditional polymer materials.Meanwhile,the molecular design can be used to modify the chemical structure to control and improve its physical and chemical properties,reflecting the incomparable advantages of inorganic materials.In this paper,benzothiadiazole and monofluoro-substituted benzothiadiazoles were introduced into 2,7-carbazole respectively to study the influence of fluorine on the photocatalytic hydrogen-producing properties of polymer semiconductors.Pyrene and trispolycarbazole and 2,7-carbazole were respectively combined to study the effect of the novel electron-donating unit trispolycarbazole on the photocatalytic hydrogen production of polymer semiconductor materials.Triphenylamine combined with trispolycarbazole and 2,7-carbazole to study the effect of hyperconjugated and nitrogen-rich units of polycarbazole on the positive electrode performance of lithium polymer in polymer semiconductors.The details were obtained as following:1.Two conjugated linear polymer networks were synthesized by using Suzuki-Miyaura cross-coupling chemistry from two kinds of bezothiadiazole-based and carbazole monomers.The polymer CZ-BT and CZ-FBT was explored for photocatalytic hydrogen produce from water.The effects of incorporation of fluorine substitutions on the optical band gap and photocatalysts properyies were investigated based on the conjugated polymers consisting of carbazole and bezothiadiazole units,where the monofluorine substitution was incorporated into the bezothiadiazole units.Contrasting the two polymers,it indicated that the fluorine substitutions slightly changed the conjugated structure,enhanced the ionization potential,and led to a slight hypsochromic shift of absorption and a improving photocatalysts.We also observed that the monofluorine substitution can greatly improve the carrier mobility.These observations demonstrated that the developed copolyment based on fluorine sbustitutions can be a promising candidate for organic catalytic.2.Two conjugated polymers based on triazatruxene,pyrene and carbazole monomers were synthesized under Suzuki-Miyaura coupling reaction and investigated as conjugated microporous polymers for photocatalytic H₂ evolution.The effects of polymers on optical property and light photocatalysts properties were investigated.The UV-vis absorption spectra demonstrated the slightly red-shift of the copolymer comprising TAT-PY relative to the CZ-PY.Compared to CZ-PY,the polymer TAT-PY showed the higher hydrogen evolution rate of 4.5?molh-1 under UV-vis light irradiation,which could be contributed to highly?-conjugated,better planarity.3.Two conjugated porous organic polymer networks were synthesized by using Suzuki-Miyaura cross-coupling chemistry from two kinds of carbazole-based and triphenylamine monomers.The polymer TPA-TAT was explored for energy storage and power supply with rechargeable lithium batteries,through the construction of built-in redox-active skeletons and highly?-conjugated skeletons in comparison to TPA-CZ.The TPA-TAT with a high free radical density structure has been firstly applied as a cathode material,and present two plateaus,with a capacity of 68mAhg^-1.Moreover,after 1000cycles,the discharge capacity of TPA-TAT was still higher than the initial capacity of TPA-CZ.UV-Vis spectra and EIS tests illustrated the smoother charge migration in the TPA-TAT polymer bulk than in that of TPA-CZ,which may be attributed to the instensive free radical density structure,the highly?-conjugated structure and the improved morphology of TPA-TAT.The improved electrochemical performance of TPA-TAT compared to TPA-CZ indicated that it is a useful strategy to design and prepare high free radical density cathode.