Pulsed‐Laser‐Engineered Cu Single Atoms in δ‐Bi 2 O 3 Nanosheets for Efficient Formate‐Producing Zn–CO 2 Batteries

ABSTRACT Herein, we report a pulsed laser irradiation in liquid (PLIL) strategy that concurrently induces phase transformation, morphological reconstruction, and single‐atom stabilization in bismuth oxide (Bi 2 O 3 ) for efficient carbon‐dioxide reduction reaction (CO 2 RR). PLIL transforms α‐Bi 2 O 3 microrods to δ‐Bi 2 O 3 nanosheets, while simultaneous anchoring atomically dispersed Cu sites within the δ‐Bi 2 O 3 lattice. The CO 2 RR activity of the PLIL‐derived δ‐Bi 2 O 3 nanosheets substantially exceeds that of α‐Bi 2 O 3 microrods and is further improved in Cu single‐atom‐stabilized δ‐Bi 2 O 3 (Cu SA/δ‐Bi 2 O 3 ) nanosheets, which deliver a high Faradaic efficiency (93.55%) with a formate yield rate of 210 µM·h −1 ·cm −2 at −1.0 V (versus the reversible hydrogen electrode). The key surface intermediates, identified using situ Raman and ex situ Fourier‐transform infrared spectroscopy, confirm the stabilization of *OCHO species during formate formation. Theoretical calculations reveal that Cu single‐atom incorporation electronically modulates the δ‐Bi 2 O 3 matrix, optimizing the intermediate adsorption energies and lowering the reaction barrier of the CO 2 ‐to‐formate pathway. Furthermore, a Zn–CO 2 battery with a Cu SA/δ‐Bi 2 O 3 cathode delivers an output voltage of 1.74 V and converts CO 2 to formate while generating electricity for over 300 h of stable operation. The Zn–CO 2 battery successfully powers light‐emitting diodes and a digital clock, underscoring its potential in real‐world energy–carbon coupling applications.