Preparation of a novel Z-scheme AgI/Ag/Bi24O31Cl10 catalyst with enhanced photocatalytic performance via an Ag0 electron transfer intermediate

In this work, a novel Z-scheme AgI/Ag/Bi24O31Cl10 photocatalyst was prepared by molecular calcination followed a precipitation–photoreduction process. AgI/Ag/Bi24O31Cl10 combines the advantages of a heterojunction with noble metal deposition. The crystalline phase, morphology, optical and photo-electrochemical properties of the prepared AgI/Ag/Bi24O31Cl10 composites have been determined. The photocatalytic activity of AgI/Ag/Bi24O31Cl10 composites was evaluated by degrading methyl orange (MO) and phenol under visible light irradiation. A mass ratio of 8% AgI in the composite was found to be optimal for the efficient degradation of MO and phenol. This was shown to degrade 84.3% of the methyl orange and 55.1% of the phenol introduced after irradiation with visible light for 2 and 4 h, respectively. Futhermore this composite is highly stable and retains excellent activity after four reaction cycles. A mechanism for the photocatalytic activity of the AgI/Ag/Bi24O31Cl10 composite has been proposed via band structure and trapping experiments. Metallic Ag0 acts as an important electron transfer intermediate between Bi24O31Cl10 and AgI. This work extends on the study of Z-scheme modifications for Bi24O31Cl10.