Molecular Regioisomerism of Benzobisthiazole‐Based Conjugated Polymers Promotes Photocatalytic Hydrogen Production

Abstract Polymer semiconductors hold great promise for photocatalytic hydrogen production due to their diverse structures and functions. Nevertheless, their photocatalytic performances are usually compromised by rapid charge recombination. Herein, a molecular regioisomerism strategy of benzobisthiazole (BT)‐based conjugated polymers is proposed for manipulating their optoelectronic properties through varying the conjugation directions of BT units. Despite subtle structural differences, the 4,8‐subsituted sample LCP‐BT‐48 exhibits an remarkably improved charge separation capability and a sixfold increase in the photocatalytic hydrogen production rate in comparison with those of the 2,6‐subsituted counterpart. Theoretical analysis demonstrates that the superior optoelectronic property of LCP‐BT‐48 is attributed to its sp² carbon‐conjugated skeletons and enhanced local polarization electric field between BT and neighboring π‐units. This work provides a new paradigm for regulating charge‐transfer dynamics in conjugated polymers for efficient photocatalysis.