Modulating Narrow Bandgap in a Diacetylene Functionalized Woven Covalent Organic Framework as a Visible Light Responsive Photocatalyst

Abstract

Woven covalent organic frameworks (COF) possess entangled 3D frameworks. The metallated version of these structures contains spatially isolated Cu(I) centers and promising optoelectronic properties because of metal‐to‐ligand charge transfer (MLCT). However, despite their potential, woven COFs have not yet been investigated as photocatalysts. In this study, a new woven COF, Cu‐PhenBDA‐COF, functionalized with diacetylene bonds is developed. Cu‐PhenBDA‐COF is fully characterized, and the optoelectronic and photocatalytic properties are compared to previously reported Cu‐COF‐505. The diacetylene bonds of the linker positively impact the optoelectronic properties of Cu‐PhenBDA‐COF and result in a narrower bandgap and better charge separation efficiency. When the Cu(I) center is removed from both woven COFs, the absorption edge is blueshifted, resulting in a wider bandgap, and there is a considerable decrease in the charge separation efficiency, underscoring the pivotal role of MLCT. This trend is reflected in the photocatalytic activity of the woven COFs toward the degradation of sulfamethoxazole in water, where the highest reaction rate constant (kapp) is recorded for the metallated diacetylene functionalized woven COF, Cu‐PhenBDA‐COF.

A diacetylene covalent organic framework through a one-step two-electron O2 reduction pathway for efficient photosynthesis of H2O2

“…Then, photoelectrons migrate to the catalyst surface exposing numerous active sites. 17–20 Therefore, we conjecture that the precise structural design of COFs by incorporating a diacetylene unit can efficiently reduce oxygen. This approach shows great promise in the efficient one-step two-electron oxygen reduction photosynthesis of hydrogen peroxide.…”