Co-Assembled Helical Polymer Nanofibers Enable Efficient CO2 Photoreduction Through Interchain Energy Transfer.

One-dimensional (1D) nanofibers have shown bright prospects for artificial CO2 photoreduction but still face formidable challenge in achieving high performance. Herein, a series of polymer nanofibers are prepared via the helical co-assembly of chiral poly{1,2-bis(4-ethynylphenyl)-1,2-diphenylethene-co-(S)-dinaphtho[2,1-d:1',2'-f][1,3]dioxepine} (P1) and poly[(9,9'-dioctylfluorenyl-2,7-diyl)-co-4,7-di(2-thienyl)-2,1,3-benzothiadiazole] (P2) using interchain energy transfer strategy. The helical nanostructure arranged through intermolecularly layered packing endows the polymer nanofibers with expansive surface area, strong light harvesting ability, and great mass diffusion kinetics arising from the abundant active sites. In comparison with the model polymer P1, the binary polymers exhibit not only minimized radiative energy loss, broaden solar light absorption, but also significantly boosted charge transport during the photoreduction process. Under simulated solar light (100 mW/cm2), P1-0.3P2 nanofibers achieved an excellent CO yield of 1165.31 µmol h-1 g-1, which is superior to that of P1 nanofibers (76.28 µmol h-1 g-1) and previously reported nanofiber photocatalysts under similar conditions. This study presents a novel strategy to fabricate conjugated polymer-based nanofibers as a promising photocatalyst for highly efficient CO2 conversion.