Ion-exchange synthesis of Ag/Ag2S/Ag3CuS2 ternary hollow microspheres with efficient visible-light photocatalytic activity

Abstract

Ternary Ag/Ag₂S/Ag₃CuS₂ hollow microspheres were synthesized via an in situ ion-exchange method using Cu₇S₄ hollow submicrospheres as the template. The as-obtained Ag/Ag₂S/Ag₃CuS₂ composite exhibited a well-defined uniform hollow microsphere morphology with an average diameter of about 1.3 μm. The photocatalytic property of the as-prepared Ag/Ag₂S/Ag₃CuS₂ hollow microsphere composite was investigated by the decomposition of methyl orange (MO) under visible light irradiation (λ > 420 nm). It was shown that the photocatalytic activity of the Ag/Ag₂S/Ag₃CuS₂ hollow microsphere was higher than those of Ag/Ag₂S, Cu₂O, Cu₇S₄ and P25 for the photodegradation of MO under visible light irradiation. Radical scavenger experiments demonstrated that superoxide radicals and holes were the main reactive species for MO degradation.