1 research outputs found
Enhanced Photocatalytic Activity of Calix[4]arene-Based Donor–Acceptor Covalent Organic Frameworks by Dual Cocatalysts
The distinctive characteristics of covalent organic frameworks
(COFs), including their high surface area, adjustable porosity, and
sturdy chemical structure, render them appealing for potential use
in photocatalytic applications. Nonetheless, the full utilization
of their photocatalytic activity has been hindered by the limited
charge separation and migration efficiencies of COFs, along with high
exciton binding energies. In this research, calix[4]arene (C4A) and
thiazolo[5,4-d]thiazole (TzTz) were selected as electron
donor and acceptor units, respectively, to produce C4A-TzTz-COF with
donor–acceptor (D–A) properties, which represents one
of the most effective approaches for promoting charge separation and
transport in organic semiconductors. As a control, C4A-PA-COF was
synthesized, and it was observed that the photocatalytic hydrogen
evolution rate of C4A-TzTz-COF with donor–acceptor (D–A)
features was 7.3 times greater than that of the former. Additionally,
Ag nanoparticles (NPs) and Pt NPs were sequentially deposited on the
surface of C4A-TzTz-COF. Ag NPs serve as providers of hot electrons
under the localized surface plasmon resonance (LSPR) effect, with
the hot electrons being injected at the conduction band of C4A-TzTz-COF.
Pt NPs, acting as catalytically active sites, effectively capture
hot electrons for cocatalysis. Ultimately, the donor–acceptor
structure of Pt–Ag3.0/C4A-TzTz-COF, featuring a
bimetallic system, significantly enhances the photocatalytic activity
in the visible light range, leading to a 2.2-fold increase in the
photocatalytic hydrogen evolution rate over C4A-TzTz-COF. The synergistic
effects of the dual cocatalysts not only facilitate charge separation
and transfer but also enable the efficient utilization of solar energy
for sustainable energy conversion. This study provides valuable insights
into the design and development of advanced COF-based photocatalytic
materials with enhanced performance, paving the way for their widespread
application in renewable energy and environmental remediation technologies