Tandem Catalysis for Photocatalytic Conversion of CO 2 into Solar Fuels: Mechanisms, Strategies, and Future Perspectives

Abstract Tandem photocatalysis has emerged as a powerful strategy for overcoming the kinetic and thermodynamic limitations of CO 2 photoconversion by integrating sequential or cooperative reaction pathways within a single system. This review highlights recent five‐year advances in tandem catalytic architectures for the photoreduction of CO 2 into solar fuels and value‐added chemicals. Five representative categories of tandem systems are highlighted: i) metal dual‐active sites, which promote stepwise reduction and C─C coupling through synergistic interactions between spatially distinct metal centers; ii) heterojunctions, which enable charge separation and multistep conversions through engineered band alignment and interfacial charge transfer; iii) metal‐semiconductor hybrids, which integrate light absorption and surface catalysis for efficient intermediate evolution; iv) two‐chamber systems, which decouple multi‐stage reactions across spatially separated compartments; and v) photoelectrochemical systems, which offer energetic and spatial decoupling of redox reactions with enhanced reaction tunability. Several key scientific issues are presented for consideration. The challenges including interfacial engineering, product selectivity, intermediate transport, and system scalability are identified, and future directions are proposed to guide the rational design of next‐generation tandem photocatalytic systems.