Novel luminescent RE/TiO2 (RE = Eu, Gd) catalysts prepared by in-situation sol-gel approach construction of multi-functional precursors and their photo or photocatalytic oxidation properties

In this context, a novel synthesis method was used to fabricate rare earth/TiO2 catalyst for the first time. Lanthanide (Eu, Gd) coordination polymers with picolinic acids were applied as precursors of titania oxide components, in particular, polyethylene glycol and polyacrylamide were added to assemble inorganic-organic hybrid polymeric network through an in-situation sol-gel technique. After sintering treatment of the multi-component precursor under 600 °C for 3 h, fluorescence excitation and emission spectra show that Eu/TiO2 crystalline phosphor exhibits strong red luminescence under excitation wavelength at 394 and 464 nm. SEM and BET indicate the two hybrids are porous and homogenous. The oxidation experiments from trivalent arsenite As(III) to pentavalent arsenate As(V) by the above two catalysts substantiate that their surfaces have higher affinity to arsenate and can enhance photocatalytic oxidation activity in comparison with pure titania.