Programmable Integration of Metal–Sulfur Coordination Motifs Into Layered Lead Halides for Photocatalytic CO ₂ Reduction

ABSTRACT

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 (MS ₂ ) 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 MS ₂ motifs transforms the interlayer region from a passive dielectric component into an active domain for charge transport and catalysis. Notably, CoS ₂ ‐ and NiS ₂ ‐intercalated lead–halide materials exhibit efficient CO ₂ ‐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 NiS ₂ as the optimal catalytic center, featuring favorable band alignment, efficient charge transfer, and moderate CO adsorption. In contrast, the FeS ₂ ‐intercalated material suffers from catalyst poisoning due to strong CO binding, while MnS ₂ ‐, ZnS ₂ ‐, and CuS ₂ ‐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.