Room temperature photocatalytic deposition of Au nanoparticles on SnS2 nanoplates for enhanced photocatalysis

Abstract

A series of SnS2/Au nanocomposites were synthesized by photocatalytic deposition of Au nanoparticles on the surface of SnS2 nanoplates at room temperature. The photocatalytic properties of the as-synthesized SnS2/Au nanocomposites were tested via both the reduction of Cr(VI) and degradation of MO in water under the irradiation of visible light (λ > 420 nm). SnS2/Au-1.0% was found to be the most photocatalytically active nanocomposite. The photocatalytic Cr(VI) reduction rate over SnS2/Au-1.0% was 2.1 times as that over SnS2 under visible light irradiation. Moreover, SnS2/Au-1.0% was also efficient and stable in the visible light-driven photocatalytic degradation of methyl orange (MO). Based on the test results of photoabsorption, transient photocurrent response and electrochemical impedance, the best photocatalytic performance of SnS2/Au-1.0% was likely attributed to its most efficient separation and transfer of photo-generated electrons and holes. Besides, the mechanisms of photocatalytic Cr(VI) reduction and MO degradation by SnS2/Au-1.0% were also explored.