Premium
Thiophene‐Based Conjugated Acetylenic Polymers with Dual Active Sites for Efficient Co‐Catalyst‐Free Photoelectrochemical Water Reduction in Alkaline Medium
Author(s) -
Borrelli Mino,
Querebillo Christine Joy,
Pastoetter Dominik L.,
Wang Tao,
Milani Alberto,
Casari Carlo,
Khoa Ly Hoang,
He Fan,
Hou Yang,
Neumann Christof,
Turchanin Andrey,
Sun Hanjun,
Weidinger Inez M.,
Feng Xinliang
Publication year - 2021
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.202104469
Subject(s) - thiophene , conjugated system , dissociation (chemistry) , polymer , raman spectroscopy , catalysis , photochemistry , chemistry , photocurrent , electrochemistry , water splitting , active site , materials science , resonance raman spectroscopy , polymer chemistry , organic chemistry , electrode , physics , optoelectronics , photocatalysis , optics
Although being attractive materials for photoelectrochemical hydrogen evolution reaction (PEC HER) under neutral or acidic conditions, conjugated polymers still show poor PEC HER performance in alkaline medium due to the lack of water dissociation sites. Herein, we demonstrate that tailoring the polymer skeleton from poly(diethynylthieno[3,2‐b]thiophene) ( pDET ) to poly(2,6‐diethynylbenzo[1,2‐b:4,5‐b′]dithiophene ( pBDT ) and poly(diethynyldithieno[3,2‐b:2′,3′‐d]thiophene) ( pDTT ) in conjugated acetylenic polymers (CAPs) introduces highly efficient active sites for water dissociation. As a result, pDTT and pBDT , grown on Cu substrate, demonstrate benchmark photocurrent densities of 170 μA cm −2 and 120 μA cm −2 (at 0.3 V vs. RHE; pH 13), which are 4.2 and 3 times higher than that of pDET , respectively. Moreover, by combining DFT calculations and electrochemical operando resonance Raman spectroscopy, we propose that the electron‐enriched C β of the outer thiophene rings of pDTT are the water dissociation active sites, while the −C≡C− bonds function as the active sites for hydrogen evolution.