UV-Visible photo-reactivity of permanently polarized inorganic nanotubes coupled to gold nanoparticles

Abstract

Hybrid aluminosilicate nanotubes (Imo-CH₃) have the ability to trap small organic molecules inside their hydrophobic internal cavity while being dispersed in water owing to their hydrophilic external surface. They also display a curvature-induced polarization of their wall, which favors reduction outside the nanotubes and oxidation inside. Here, we coupled bare plasmonic gold nanoparticles (GNPs) with Imo-CH₃ and analyzed for the first time the redox reactivity of these hybrid nano-reactors upon UV illumination. We show that the coupling between GNPs and Imo-CH₃ significantly enhances the nanotube photocatalytic activity, with a large part of water reduction occurring directly on the gold surface. The coupling mechanism strongly influences the initial H₂ production rate, which can go from ×10 to more than ×90 as compared to bare Imo-CH₃ depending on the synthesis route of the GNPs. The present results show that this hybrid photocatalytic nano-reactor benefits from a synergy of polarization and confinement effects that facilitate efficient H₂ production.