Synergetic effect of dual co-catalysts on the activity of BiVO4 for photocatalytic carbamazepine degradation

Abstract

An efficient visible-light driven three components photocatalyst for carbamazepine (CBZ) degradation has been assembled by co-loading reduction cocatalyst Pt and oxidation cocatalyst Co₃O₄ (MnO_x) on BiVO₄. The apparent rate constant of the three components photocatalyst Pt/BiVO₄/Co₃O₄ for degradation of CBZ is 54 times that of Co₃O₄/BiVO₄ and 2.5 times that of Pt/BiVO₄, which shows a synergetic effect in the photocatalytic activity. The same synergetic effect is also observed for Pt/BiVO₄/MnO_x. The spatial separation of the reduction and oxidation cocatalysts could reduce the recombination of the photogenerated charges, which mainly accounts for the high photocatalytic activity of the three components photocatalyst. The photocatalytic intermediates of CBZ were detected by HPLC-ESI-MS, and a deductive degradation pathway of CBZ was proposed.