Photocatalytic Hydrogen Production from Water using Organic-Inorganic Hybrid Nanoparticles

Abstract

Anchoring of [Pt(tpy)Cl]Cl complex to the (3-aminopropyl)trimethoxysilane-modified mesoporous silica (MCM-48) successfully gives a new type of photocatalyst with unique photoluminescence property at room temperature. At low Pt loadings, Pt (II) complex exists in an isolated state without mutual interaction, which exhibits strong photoluminescence emission due to the ³LC and/or ³MLCT transitions maximized near 530 nm. Contrastingly, such emissions significantly decrease at high Pt loadings accompanied with a new emission at around 620 nm due to the ³MMLCT transition originating from short Pt···Pt interactions. The photocatalytic activities in the hydrogen production under aqueous conditions correspond well with the increasing intensity of ³MMLCT emission. It can be suggested that the anchored Pt (II) complexes, which are closely related to each other, behave as single-component bifunctional catalyst enabling both visible-light sensitization and H₂-evolution without the need for an additional electron relay.