posted on 2023-05-12, 08:29authored byTingwei Cai, Hanchang Hu, Haoyang Xu, Jiani Xu, Chen Meng, Jinxin He, Jin Wen, Qiangqiang Zhao
Highly
efficient light-harvesting systems (LHSs) with the sequential
energy transfer process are important for utilizing solar energy in
photosynthesis. However, most light-harvesting systems are nanoparticles
and vesicles, which are difficult to prepare and recycle. In this
paper, we developed a light-harvesting system based on amino-methyl
coumarin acid (AMCA), C.I. Basic Yellow 40 (BY 40), and phloxine B
(PhB) organic dyes for photocatalytic cross-dehydrogenative coupling
(CDC) reactions. The conversion of the CDC reaction using the AMCA–BY
40–PhB system could reach 98.77% in ethanol, which was much
higher than that with the main active catalyst PhB alone. In order
to recycle and reuse the above catalysts, a facile, simple, and highly
efficient light-harvesting cotton photocatalyst AMCA/BY 40/β-SCD-PhB-MCFs
was prepared via three steps of cationization of cotton fibers (MCFs),
sulfobutylether-β-cyclodextrin (β-SCD) inclusion of donor
fluorophores, and final immobilization of fluorophores. These light-harvesting
cotton fibers showed excellent catalytic performance, and the catalysis
rate of the CDC reaction was 1.57 times higher than that of the PhB-MCFs
alone. Its special “ring dyeing” and hierarchical pore
structure provided a favorable microenvironment for photocatalysis.
The wide range in light absorption, highly efficient energy transfer
(53.1%), and antenna efficiency (15.6) of the light-harvesting cotton
fiber synergistically enhanced the energy transfer process. Furthermore,
the light-harvesting cotton fibers showed high reusability, which
could be easily recovered and reused five times without significant
catalyst leaching. More interestingly, the fiber could be easily loaded
in microchannels of the continuous flow reactor to catalyze the CDC
reaction, which successfully achieved gram-scale photosynthesis due
to the large specific surface area and easy mass transfer of fiber
catalysts.