Open AccessCovalent Organic Framework Nanoplates Enable Solution-Processed Crystalline Nanofilms for Photoelectrochemical Hydrogen Evolution
Author(s) -
Liang Yao,
Andrés RodríguezCamargo,
Xiangjian Meng,
David Mücke,
Roman Guntermann,
Yongpeng Liu,
Lars Grunenberg,
Alberto JiménezSolano,
Sebastian T. Emmerling,
Viola Düppel,
Kevin Sivula,
Thomas Bein,
Haoyuan Qi,
Ute Kaiser,
Michaël Grätzel,
Bettina V. Lotsch
Publication year - 2022
Publication title -
journal of the american chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.115
H-Index - 612
eISSN - 1520-5126
pISSN - 0002-7863
DOI - 10.1021/jacs.2c01433
Subject(s) - photocurrent , heterojunction , covalent organic framework , nanotechnology , chemistry , hydrogen , photoelectrochemistry , water splitting , photoelectrochemical cell , semiconductor , covalent bond , chemical engineering , materials science , electrode , optoelectronics , photocatalysis , electrolyte , electrochemistry , catalysis , organic chemistry , engineering
As covalent organic frameworks (COFs) are coming of age, the lack of effective approaches to achieve crystalline and centimeter-scale-homogeneous COF films remains a significant bottleneck toward advancing the application of COFs in optoelectronic devices. Here, we present the synthesis of colloidal COF nanoplates, with lateral sizes of ∼200 nm and average heights of 35 nm, and their utilization as photocathodes for solar hydrogen evolution. The resulting COF nanoplate colloid exhibits a unimodal particle-size distribution and an exceptional colloidal stability without showing agglomeration after storage for 10 months and enables smooth, homogeneous, and thickness-tunable COF nanofilms via spin coating. Photoelectrodes comprising COF nanofilms were fabricated for photoelectrochemical (PEC) solar-to-hydrogen conversion. By rationally designing multicomponent photoelectrode architectures including a polymer donor/COF heterojunction and a hole-transport layer, charge recombination in COFs is mitigated, resulting in a significantly increased photocurrent density and an extremely positive onset potential for PEC hydrogen evolution (over +1 V against the reversible hydrogen electrode), among the best of classical semiconductor-based photocathodes. This work thus paves the way toward fabricating solution-processed large-scale COF nanofilms and heterojunction architectures and their use in solar-energy-conversion devices.