Coordination-driven bandgap engineering in photocatalytic CO2 reduction: From electronic structure design to mechanistic insights and benchmarking

초록

The escalating global carbon footprint demands sustainable technologies to decouple energy production from fossil reserves. Solar-driven photocatalytic CO2 reduction offers a sustainable closed-loop approach for transforming the primary greenhouse gas into high-value chemical feedstocks. However, conventional semiconductor photocatalysts suffer from poor visible-light absorption, rapid charge recombination, and sluggish multi-electron transfer kinetics. This review delivers a comprehensive analysis of coordination-driven bandgap engineering, establishing a unifying framework that bridges molecular configuration, atomic-scale defects, and heterojunction architectures. Photocatalytic mechanics are systematically evaluated, with emphasis placed on how reactive intermediate lifetimes and selectivities are governed by atomic coordination spheres and localized electronic fields. Bandgap engineering, moving beyond traditional classifications, is categorized into three mechanistically distinct pillars: intrinsic band structure manipulation (doping and vacancy engineering), extrinsic electronic tuning (supramolecular assembly and plasmonic fields), and interfacial charge separation (e.g., S- and Z-scheme heterojunctions). The novelty of this review is addressed in four primary dimensions: (1) unraveling multi-defect coupling mechanics and thermodynamic trade-offs; (2) correlating active site architectures with low-overpotential C2+ pathways; (3) integrating in-situ/operando characterization with Density Functional Theory modeling for a real-time band alignment mapping; and (4) establishing a standardized performance matrix across diverse platforms, including metal oxides, transition metal dichalcogenides, MXenes, bismuth-based photocatalysts, carbon-based semiconductors, and single-atom catalysts. Using coordination chemistry principles, this review offers a definitive strategic blueprint for designing next-generation, high-efficiency photocatalytic systems for scalable solar fuel generation.

키워드