The photocatalytic performances of Bi2MTaO7 (M = Ga, In) photocatalysts for environmental cleaning under visible-light

Abstract

Herein, we present the Bi2GaTaO7 (BGTO) and Bi2InTaO7 (BITO) semiconductors as visible-light-driven photocatalysts for environmental cleaning, including photocatalytic oxidation of rhodamine B and reduction of dichromate ion. Experimental results show that both intrinsic and modified BGTO have better photocatalytic oxidation and reduction activities than that of BITO. The best cocatalysts for BGTO and BITO in photocatalytic degradation and reduction reactions are CuO and Ag, respectively, but the optimal amount is different. The kinetic constants of BGTO-3%Cu and BITO-2%Cu are 3.4-fold and 3.0-fold in comprise with the inherent BGTO and BITO, respectively. The kinetic constants of BGTO-4%Ag and BITO-4.5%Ag are 3.6-fold and 4.0-fold by comparing the intrinsic BGTO and BITO, respectively. The photocatalytic mechanisms of degradation and reduction reactions are also proposed in this paper.