Programmable Integration of Metal-Sulfur Coordination Motifs Into Layered Lead Halides for Photocatalytic CO₂...

Two-dimensional (2D) lead halides provide a versatile platform for interlayer engineering, but their functionality is limited by electronically inert spacers. The integration of electronically active inorganic motifs into layered lead halide lattices remains a major challenge. Herein, we report a coordination-directed strategy that enables the programmable incorporation of transition-metal-sulfur (MS₂) units into layered lead halides via synergistic carboxylate-sulfide dual binding, affording a family of 12 crystalline frameworks with tunable compositions. Embedding electronically and catalytically active MS₂ motifs transforms the interlayer region from a passive dielectric component into an active domain for charge transport and catalysis. Notably, CoS₂- and NiS₂-intercalated lead-halide materials exhibit efficient CO₂-to-CO conversion, achieving rates up to 4.32 mmol g^-1 h^-1, an apparent quantum yield of 1.76%, and near-unity selectivity. Combined in situ spectroscopy and density functional theory calculations identify NiS₂ as the optimal catalytic center, featuring favorable band alignment, efficient charge transfer, and moderate CO adsorption. In contrast, the FeS₂-intercalated material suffers from catalyst poisoning due to strong CO binding, while MnS₂-, ZnS₂-, and CuS₂-based systems are limited by unfavorable energy alignment with the photosensitizer or competing self-reduction pathways. This work introduces a new paradigm that integrates efficient light-harvesting, charge transport, and catalytic functionality within a single layered semiconductor.