Photosynthesis of hydrogen peroxide in a two-phase system by hydrophobic Au nanoparticle-deposited plasmonic TiO2 catalysts

Recently, the combination of photocatalytic reduction and oxidation reactions has attracted great attention, especially for the photocatalytic synthesis of hydrogen peroxide (H2O2) integrated with benzyl alcohol (BA) oxidation reaction. The plasmonic Au nanoparticles (NPs) driven by surface plasmon resonance (SPR) excitation can be efficiently applied for photocatalysis. In this study, the effect of a hydrophobic Au-deposited TiO2 material (OPA-Au/TiO2) modified with octadecylphosphonic acid (OPA) on the photosynthesis H2O2 performance in a two-phase system, comprising water and BA phases, is investigated. The SPR effect of plasmonic Au NPs facilitates the generation of substantial photoexcited hot electrons, which transfer to the conductive band of TiO2. Moreover, OPA-Au/TiO2 present in the BA phase, exhibits dramatically enhanced activity (567 μmol g−1 h−1) under λ > 420 nm irradiation owing to the separation from produced H2O2 in the aqueous phase, which efficiently suppresses the H2O2 decomposition.