Bismuth‐Based Semiconductors in Photocatalytic CO ₂ Reduction: Catalysts, Progress, and Future Perspectives

ABSTRACT Carbon dioxide (CO 2 ) in the environment continues to rise due to emissions from human activities. Photocatalytic reduction of CO 2 into value‐added chemicals and fuels using solar energy has attracted significant research interest as an important way to achieve “carbon neutrality.” However, existing photocatalysts suffer from limitations such as the inherent high stability of O=C=O bond dissociation energy, severe photogenerated carrier complexation, and slow surface reaction kinetics, which constrain the efficiency of photocatalytic reduction of CO 2 . Bismuth (Bi)‐based semiconductor materials, such as Bi 2 O 3 , Bi 2 WO 6 , BiVO 4 , and BiOX (X = Cl, Br, I), exhibit significant advantages in photocatalytic reduction of CO 2 due to their unique layered structure, suitable visible light responsive bandgap, and tunable electronic energy bands. This review summarizes recent advances in the development of Bi‐based photocatalysts to enhance the efficiency of solar‐driven CO 2 reduction. The main strategies investigated include the heteroatom doping, micro‐morphology tuning, construction of oxygen vacancies and heterojunction, which synergistically enhance the ability to trap light, the efficiency of carrier separation, and the capacity of CO 2 adsorption/activation. However, precise control of doping concentration, vacancy distribution, and the interfacial charge transfer mechanism remains a challenge.