Photocatalytic epoxidation of propene with molecular oxygen under visible light irradiation on V ion-implanted Ti-HMS and Cr-HMS mesoporous molecular sieves

摘要

The metal ion-implantation with V ions was effective to shift the absorption band of Ti-containing mesoporous molecular sieves (V/Ti-HMS, V/Ti-MCM-41) to the longer wavelengths. V/Ti-HMS and V/Ti-MCM-41 performed the photoepoxidation of propene with molecular oxygen under UV irradiation with the longer wavelength (λ > 340 nm), while no reaction proceeded on the original Ti-HMS. Cr-containing mesoporous molecular sieves (Cr-HMS) could absorb visible light and showed the photoepoxidation under visible light irradiation (λ> 450 nm). The charge transfer excited state of the tetrahedral chromium oxide moieties dispersed on mesoporous silica played a significant role in the photocatalytic reaction.