Photocatalytic
reduction of molecular oxygen is a promising route
toward sustainable production of hydrogen peroxide (H
2
O
2
). This challenging process requires photoactive semiconductors
enabling solar energy driven generation and separation of electrons
and holes with high charge transfer kinetics. Covalent organic frameworks
(COFs) are an emerging class of photoactive semiconductors, tunable
at a molecular level for high charge carrier generation and transfer.
Herein, we report two newly designed two-dimensional COFs based on
a (diarylamino)benzene linker that form a Kagome (
kgm
) lattice and show strong visible light absorption. Their high crystallinity
and large surface areas (up to 1165 m
2
·g
–1
) allow efficient charge transfer and diffusion. The diarylamine
(donor) unit promotes strong reduction properties, enabling these
COFs to efficiently reduce oxygen to form H
2
O
2
. Overall, the use of a metal-free, recyclable photocatalytic system
allows efficient photocatalytic solar transformations.
Covalent Organic Frameworks (COFs) have recently emerged as light‐harvesting devices, as well as elegant heterogeneous catalysts. The combination of these two properties into a dual catalyst has not yet been explored. We report a new photosensitive triazine‐based COF, decorated with single Ni sites to form a dual catalyst. This crystalline and highly porous catalyst shows excellent catalytic performance in the visible‐light‐driven catalytic sulfur–carbon cross‐coupling reaction. Incorporation of single transition metal sites in a photosensitive COF scaffold with two‐component synergistic catalyst in organic transformation is demonstrated for the first time.
Four highly porous covalent organic frameworks (COFs) containing pyrene units were prepared and explored for photocatalytic H2O2 production. The experimental studies are complemented by density functional theory calculations, proving that the pyrene unit is more active for H2O2 production than the bipyridine and (diarylamino)benzene units reported previously. H2O2 decomposition experiments verified that the distribution of pyrene units over a large surface area of COFs plays an important role in catalytic performance. The Py‐Py‐COF though contains more pyrene units than other COFs which induces a high H2O2 decomposition due to a dense concentration of pyrene in close proximity over a limited surface area. Therefore, a two‐phase reaction system (water‐benzyl alcohol) was employed to inhibit H2O2 decomposition. This is the first report on applying pyrene‐based COFs in a two‐phase system for photocatalytic H2O2 generation.
Four highly porous covalent organic frameworks (COFs) containing pyrene units were prepared and explored for photocatalytic H 2 O 2 production. The experimental studies are complemented by density functional theory calculations, proving that the pyrene unit is more active for H 2 O 2 production than the bipyridine and (diarylamino)benzene units reported previously. H 2 O 2 decomposition experiments verified that the distribution of pyrene units over a large surface area of COFs plays an important role in catalytic performance. The Py-Py-COF though contains more pyrene units than other COFs which induces a high H 2 O 2 decomposition due to a dense concentration of pyrene in close proximity over a limited surface area. Therefore, a twophase reaction system (water-benzyl alcohol) was employed to inhibit H 2 O 2 decomposition. This is the first report on applying pyrene-based COFs in a two-phase system for photocatalytic H 2 O 2 generation.
The photocatalytic oxygen reduction reaction (ORR) towards hydrogen peroxide (H2O2) is a promising but challenging alternative to the industrial anthraquinone process. Crystalline porous covalent organic frameworks (COFs), a new generation...
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