Synthesis and photochemical properties of La-doped HCa 2Nb 3O 10

Abstract

The photocatalysts H 1− x La x Ca 2− x Nb 3O 10 ( x = 0, 0.25, 0.5, 0.75) was synthesized by conventional solid state reaction followed by an ion-exchange reaction. They were characterized by power X-ray diffraction, UV–vis diffusive reflectance and scan electron microscope. The effect of substitution of La 3+ for Ca 2+ in HCa 2Nb 3O 10 has been studied on the photocatalytic decomposition of water under UV light irradiation with methanol as electron donor and Pt as promoter catalyst. Both the optical property and photocatalytic activity of H 1− x La x Ca 2− x Nb 3O 10 were varied by the substitution of La 3+ for Ca 2+. The x value in H 1− x La x Ca 2− x Nb 3O 10 had an important effect on the photocatalytic activity of the catalyst. When the x = 0.5, the H 1− x La x Ca 2− x Nb 3O 10/Pt showed a photocatalytic activity of 169 cm 3 h −1 g −1 hydrogen evolution rate in 10 vol.% methanol solution under irradiation from a 100 W mercy lamp at 333 K.