Robust Multimetallic Plasmonic Core-Satellite Nanodendrites: Highly Effective Visible-Light-Induced Colloidal CO₂ Photoconversion System

The present report demonstrated the synthesis of trimetallic Pt-nanodots (PtNDs, 3-4 nm) and TiO₂ (4-5 nm) coated Au nanoparticles (Pt@TiO₂-AuNPs) with spherical dendritic shape, robust structure, and high colloidal stability. Prepared plasmonic nanodendrites were tested for CO₂ photoconversion to HCOOH in the aqueous medium at room temperature and showed significant conversion rate with 3.12% of chemical yield and 1.84% of quantum yield. There was a remarkable improvement in the photocatalytic efficiency of TiO₂-AuNPs after PtNDs decoration as 312-fold increase in the CO₂ photoconversion efficiency with trimetallic Pt@TiO₂-AuNPs nanodendrites in comparison to bare AuNPs in the presence of Xe lamp (visible light). Prepared nanodendrites also showed notable efficiency in NIR light and solar simulator illumination. The action spectra (quantum yield vs wavelength of monochromatic light) has shown plasmon-enhanced reaction progress and robustness of prepared colloidal nanodendrites. The spherical nanodendrites have been tested for at least five reaction cycles and showed consistent conversion efficiency with exceptional morphological and colloidal stability.