Polyoxometalate Induced Bismuth Sulfide Sub‐1 nm Nanowires as Efficient Photocathodes in Li‐CO 2 Batteries

ABSTRACT The 1D sub‐1 nm nanowires (SNWs) usually possess a highly promising avenue in catalysis and energy storage fields owing to their high aspect ratios facilitating charge transport, and near 100% surface atomic exposure offering abundant active sites. However, current research is mainly focused on metal oxide SNWs, whereas the synthesis of sulfide SNWs has been rarely reported. Herein, a new kind of Bi 2 S 3 ‐phosphomolybdic acid (Bi 2 S 3 ‐PMA) SNWs induced by polyoxometalate clusters has been successfully prepared. Molecular dynamics simulation demonstrates that PMA and Bi 2 S 3 co‐assemble into stable 1D SNWs via non‐covalent interactions. Benefiting from the unique sub‐1 nm structure and the synergetic effects of Bi 2 S 3 and PMA, the SNWs exhibit enhanced light absorption ability, well‐matched energy band structure, and efficient separation/transfer capability of photo‐generated carriers. As the cathode catalyst in light‐assisted Li‐CO 2 batteries (LCBs), the Bi 2 S 3 ‐PMA‐based LCBs deliver a low overpotential of 0.22 V, superior cycling stability for 300 h at 0.01 mA cm −2 and 150 h at 0.05 mA cm −2 . Meanwhile, the battery also realizes an exceptionally long‐term lifetime of 4000 h under no light. Density functional theory calculations disclose that the presence of electron‐rich PMA promotes the adsorption of LiCO 2 and Li 2 CO 3 on SNWs, which further boosts battery efficiency.