Regulating donor-acceptor interactions in triazine-based conjugated polymers for boosted photocatalytic hydrogen production

The donor-acceptor (D-A) interactions between the triazine ring unit and adjacent substituents is one of the decisive factors that affect the performance of triazine-based conjugated polymer photocatalysts. Herein, we design and synthesize novel conjugated polymers by introducing electron-drawing 1,3,4-oxadiazole units into 1,3,5-triazine-based pi-conjugated skeletons for photocatalytic hydrogen production. Compared with the bulk polymer, the modified photocatalysts show extended visible light harvesting and boosted charge separation. Notably, under the irradiation of full-spectrum solar light, as-synthesized polymer with bi-1,3,4-oxadiazole linkage (denoted as TCP-BOXD) shows a highly improved hydrogen-evolving rate up to 3000 mu mol g(-1) h(-1). Furthermore, DFT calculation reveals that N atoms in the introduced 1,3,4-oxadiazole unit, coupled with those in the triazine ring, act as synergistic bi-active sites for superior photocatalytic hydrogen production. Our findings may help the rational design and controllable synthesis of novel triazine-based conjugated polymers for photocatalysis.