Affiliation:
1. Molecular Materials Laboratory Chemistry and Physics of Materials Unit School of Advanced Materials (SAMat) Jawaharlal Nehru Centre for Advanced Scientific Research Jakkur Bangalore 560064 India
2. New Chemistry Unit Jawaharlal Nehru Centre for Advanced Scientific Research Jakkur Bangalore 560064 India
Abstract
AbstractThe need for carbon‐neutralization technologies has prompted significant interest in developing materials for CO2 reduction. Donor–acceptor (D–A) based flexible porous coordination polymers {[Zn(o‐phen)(ndc)].(guest)}n, (guest = anthracene = 1‐Ant, and pyrene = 1‐Pyr) are reported as photocatalysts for CO2RR, yielding higher order CH4 product. Electron‐rich anthracene (Ant) and pyrene (Pyr) guests are confined within nanopores, forming D–A charge transfer (CT) complexes with o‐phen ligand of the host. CT interaction enhances visible light absorption and modulates excitonic properties of the photocatalyst by electronic push‐pull effect (exciton binding energy 87 meV for 1‐Ant and 104 meV for 1‐Pyr). Electron donation capability varies from Pyr to Ant, affecting catalytic properties; 1‐Ant yields 1.24 mmolg−1 of CH4 (0.47 mmolg−1 for 1‐Pyr) with CO as minor product. A mixed‐metal multivariate PCP {[Zn0.55Co0.45(o‐phen)(ndc)].(Ant)}n, (1′‐Ant) prepared based on solid‐solution approach by substituting Zn(II) with redox‐active Co(II) enhances CH4 production (2.79 mmolg−1, ≈94% selectivity). D–A CT complex harvests visible light and channels electrons to Co(II) for CO2RR. In situ DRIFTS and theoretical studies elucidate Co(II) site's role in CO2 binding and stabilizing reaction intermediates. This work underscores guest‐modulated electron transfer in PCPs for tailoring catalytic properties by introducing a redox‐active metal in a multivariate approach.