Silica microspheres functionalized with porphyrin as a reusable and efficient catalyst for the photooxidation of 1,5-dihydroxynaphthalene in aerated aqueous solution

Abstract Silica microspheres functionalized with 5-(4-allyloxy)phenyl-10,15,20-tri(2,6-dichlorophenyl)porphyrin (APTDCPP), SiO 2 -MPS–APTDCPP, have been synthesized by sol–gel process and characterized using SEM, FT-IR, UV–vis and TG. The SEM images show that the morphology of the silica microspheres is spheriform and uniform with size of 2–4 μm. Their photocatalysis activity to oxidize 1,5-dihydroxynaphthalene under visible light irradiation in aerated aqueous solution has been studied and the main product has also been identified by 1 H NMR and MS techniques. The factors affecting photocatalytic oxidation, such as oxygen concentration, initial concentration of substrate, amount of catalyst and the addition of NaN 3 , have been studied in detail. The experimental results confirmed that the hybrid material is a mild, reusable and efficient heterogeneous catalyst for the photooxidation of 1,5-dihydroxynaphthalene in aerated aqueous solution.