biostudies-literatureWang FProject of Science & Technology Office of Jiangsu ProvinceNational Natural Science Foundation of Chinae11617https://www.ebi.ac.uk/biostudies/studies/S-EPMC12806239biostudies-literatureUnknown13(3)The photocatalytic conversion of CO₂ into the renewable fuels is a promising strategy to address energy and environmental challenges, however, its limited application is mainly attributed to the inefficient charge separation and lack of active sites in conventional catalysts. Here, a spin-polarization strategy using Co²⁺ doping in lead-free perovskite Cs₃Bi₂Br₉ (CBB) synergized with an external magnetic field (MF), is reported to achieve highly efficient CO₂ reduction. The optimized Co-doped CBB (0.2CBB) exhibited a 2.6-fold enhancement in CO production rate (35.04 µmolg^-1h^-1) compared to the pristine CBB, with further improvement to 86.56 µmolg^-1h^-1 under 200 mT MF. Advanced charaAdvanced science (Weinheim, Baden-Wurttemberg, Germany)Manipulating the Spin State of Perovskite Cs<sub>3</sub>Bi<sub>2</sub>Br<sub>9</sub> by Co-Doped for Efficient Photocatalytic CO<sub>2</sub> Reduction.PMC1280623952070070KB20181043Xia YXie YHe ZZhang JHe GFu XChen GDai GWang FSu JSiddique MSfalseManipulating the Spin State of Perovskite Cs<sub>3</sub>Bi<sub>2</sub>Br<sub>9</sub> by Co-Doped for Efficient Photocatalytic CO<sub>2</sub> Reduction.The photocatalytic conversion of CO₂ into the renewable fuels is a promising strategy to address energy and environmental challenges, however, its limited application is mainly attributed to the inefficient charge separation and lack of active sites in conventional catalysts. Here, a spin-polarization strategy using Co²⁺ doping in lead-free perovskite Cs₃Bi₂Br₉ (CBB) synergized with an external magnetic field (MF), is reported to achieve highly efficient CO₂ reduction. The optimized Co-doped CBB (0.2CBB) exhibited a 2.6-fold enhancement in CO production rate (35.04 µmolg^-1h^-1) compared to the pristine CBB, with further improvement to 86.56 µmolg^-1h^-1 under 200 mT MF. Advanced chara2026-01-01T00:00:00Z2026 Jan2026-06-06T13:53:05.769Z2026-05-31T03:09:56.015ZS-EPMC128062394126198610.1002/advs.202511617