Zhao Ziqi, Zhan Shaoqi, Feng Lu, Liu Chang, Ahlquist Mårten S G, Wu Xiujuan, Fan Ke, Li Fusheng, Sun Licheng
State Key Laboratory of Fine Chemicals, Institute of Artificial Photosynthesis, DUT-KTH Joint Education and Research Centre on Molecular Devices, Dalian University of Technology, Dalian 116024, P. R. China.
Department of Theoretical Chemistry and Biology, School of Engineering Sciences in Chemistry Biotechnology and Health, KTH Royal Institute of Technology, 10691 Stockholm, Sweden.
ACS Appl Mater Interfaces. 2021 Sep 1;13(34):40602-40611. doi: 10.1021/acsami.1c10561. Epub 2021 Aug 17.
Organic semiconductors provide significant potentials for the construction of photoelectrochemical (PEC) cells for solar hydrogen production because of their highly tunable properties. Herein, on carbon fiber paper (CFP) surface, pyridyl (Py), and 4,4'-bipyridin-1-ium (Py) groups were introduced into polythiophene (pTH) semiconductor by electrochemical copolymerization, respectively. After assembly with the Co(dmgBF) type catalyst (CoB, dmgBF = difluoroboryldimethylglyoximate), the CoB@Py-pTH/CFP photocathode displayed nearly twice the photocurrent enhancement (550 μA cm at 0.15 V vs reversible hydrogen electrode, RHE) comparing to that generated by the CoB@Py-pTH/CFP photocathode (290 μA cm at 0.15 V vs RHE) for light-driven H generation under AM 1.5 solar illumination. Investigation of the mechanism revealed that the introduction of the positively charged pyridinium groups could improve the intrinsic Co(dmgBF) catalyst activity for the H generation reaction. Meanwhile, the positively charged pyridinium groups serve as -type dopants to increase the semiconductor bulk charge transfer rate and act as electron transfer mediators to promote the interfacial charge transfer kinetics between the catalyst and the pTH-based organic semiconductor.
有机半导体因其高度可调的特性，在用于太阳能制氢的光电化学（PEC）电池的构建方面具有巨大潜力。在此，在碳纤维纸（CFP）表面，通过电化学共聚分别将吡啶基（Py）和4,4'-联吡啶鎓（Py）基团引入聚噻吩（pTH）半导体中。与CoB@Py-pTH/CFP光阴极（在0.15 V对可逆氢电极，RHE时为290 μA cm）相比，在Co(dmgBF)型催化剂（CoB，dmgBF = 二氟硼基二甲基乙二肟）组装后，CoB@Py-pTH/CFP光阴极在AM 1.5太阳光照下用于光驱动产氢时，光电流增强近两倍（在0.15 V对RHE时为550 μA cm）。对其机理的研究表明，带正电的吡啶鎓基团的引入可以提高Co(dmgBF)催化剂对产氢反应的固有活性。同时，带正电的吡啶鎓基团作为n型掺杂剂提高半导体本体电荷转移速率，并作为电子转移介质促进催化剂与基于pTH的有机半导体之间的界面电荷转移动力学。
