Photophysical Property and Photocatalytic Activity of New Gd2InSbO7 and Gd2FeSbO7 Compounds under Visible Light Irradiation

摘要

Gd2InSbO7 and Gd2FeSbO7 were synthesized first, and their structural and photocatalytic properties were studied. The lattice parameters and the band gaps for Gd2InSbO7 and Gd2FeSbO7 were 10.449546 Å, 10.276026 Å, 2.897 eV and 2.151 eV. The photocatalytic degradation of rhodamine B was performed with Gd2InSbO7 and Gd2FeSbO7 under visible light irradiation. Gd2InSbO7 and Gd2FeSbO7 had higher catalytic activity compared with Bi₂InTaO₇. Gd₂FeSbO₇ exhibited higher catalytic activity than Gd₂InSbO₇. The photocatalytic degradation of rhodamine B followed with the first-order reaction kinetics, and the first-order rate constant k was 0.01606, 0.02220 or 0.00329 min⁻¹ with Gd₂InSbO₇, Gd₂FeSbO₇ or Bi₂InTaO₇ as photocatalyst. Complete removal of rhodamine B was observed after visible light irradiation for 225 min or 260 min with Gd₂FeSbO₇ or Gd₂InSbO₇ as photocatalyst. The evolution of CO₂ was realized, and it indicated continuous mineralization of rhodamine B during the photocatalytic process. The possible photocatalytic degradation pathway of rhodamine B was proposed.