Template-assisted in-situ synthesis of porous AgBr/Ag composite microspheres as highly efficient visible-light photocatalyst

Abstract

A novel one step template-assisted in-situ synthetic route was established to synthesize porous AgBr/Ag composite microsphere. Herein, CuBr microsphere was selected as a chemical template to generate porous AgBr/Ag composite microsphere via one step in-situ reaction, where, CuBr not only provided Br− ion to generate AgBr but also released Cu+ ion to reduce Ag+ ion into elemental Ag. The experimental results revealed that the AgBr/Ag composite microsphere could be obtained easily and quickly with the established in-situ synthetic route, while the composition (the ratio of AgBr to Ag) of the final products could be tuned through changing the ratio of CuBr template to Ag+ ion in the precursor solution. Besides, the in-situ formation procedure of porous AgBr/Ag composite microsphere was investigated and found that the template-assisted in-situ synthesis of porous AgBr/Ag composite microsphere was dominated by a kind of synergistic in-situ reaction mechanism involving the ion-exchange reaction between CuBr microsphere and Ag+ as well as follow-up in-situ reduction reaction of Ag+ ion by Cu+ ion released from the CuBr template. The photocatalytic performance of the as-synthesized AgBr/Ag composite microspheres with different compositions were evaluated by monitoring the decolorization of methyl orange (an organic dye; denoted as MO) and the degradation of phenol under visible-light irradiation, and the as-synthesized porous AgBr/Ag composite microsphere with AgBr/Ag ratio of 1:1 was capable of bleaching 94% MO within 20min while it can decompose 79% of phenol in 180min, showing excellent visible-light photocatalytic activity.