新型亲水性共轭聚合物的制备及光催化制氢性能

Preparation of Novel Hydrophilic Conjugated Polymers and Their Applicationin Photocatalytic Hydrogen Evolution

制备了聚({4,8-双[(2,5,8,11,14,17,20-七氧二十二烷-22-基)氧基]苯并[1,2-b∶4,5-b′]二噻吩}-交替-[2,5-二(噻唑-2-基)吡嗪])(P7O-2N-2N)和聚({4,8-双[(2,5,8,11,14,17,20-七氧二十二烷-22-基)氧基]苯并[1,2-b∶4,5-b′]二噻吩}-交替-[3,6-双(5-溴-2-噻吩基)-1,2,4,5-四嗪])(P7O-4N)2个亲水性共轭聚合物,通过调节主链含氮杂环上氮原子的位置,系统研究了主链结构对材料吸收光谱、能级、氢结合自由能及光催化性能的影响.研究发现,与P7O-2N-2N相比,P7O-4N表现出更强的链间聚集、更低的氢结合自由能及更好的光催化制氢性能.

The application of organic conjugated polymers in photocatalytic hydrogen production has received increasing attention.However,most conjugated polymer photocatalysts showed unsatisfied photocatalytic hydrogen evolution,and the structure-performance relationship of conjugated polymers-based photocatalysts needs further exploration.In this study,we designed two conjugated polymers[poly({4,8-bis[(2,5,8,11,14,17,20-heptaoxadocosan-22-yl)oxy]benzo[1,2-b∶4,5-b′]dithiophene}-alt-[2,5-di(thiazol-2-yl)pyrazine])(P7O-2N-2N)and poly({4,8-bis[(2,5,8,11,14,17,20-heptaoxadocosan-22-yl)oxy]benzo[1,2-b∶4,5-b′]dithiophene}-alt-[3,6-di(thiophen-2-yl)-1,2,4,5-tetrazine])(P7O-4N)]with hydrophilic side chains and nitrogen-contained heterocycles in backbones.The chemicals tructures and their influence on the absorption spectrum,energy level,free energy of hydrogen adsorption and photocatalytic performance of the material were systematically studied.The results showed that the conjugated polymer P7O-4N having a 3,6-bis(thien-2-yl)-1,2,4,5-tetrazine structure showed stronger inter-chain aggregation,lower hydrogen bonding free energy,and better photocatalytic hydrogen production performance than polymer P7O-2N-2N with 2,5-bis(thiazole-2-yl)-pyrazide structure.