Monolayer MoS2 decorated Cu7S4-Au nanocatalysts for sensitive and selective detection of mercury(II)

Abstract

Sensitive and selective detection of Hg(II) contamination is of great importance with concern of public health. Herein, we successfully fabricated monolayer MoS2 (S-MoS2) decorated Cu7S4-Au (Cu7S4-Au@S-MoS2) nanocomposite modified electrode for the sensitive and selective detection of Hg(II) via anodic stripping voltammetric technique. Due to the excellent electrocatalytic reduction performance arisen from the abundant active edge sites of smallmonolayer MoS2 and good affinity of Au toward Hg, the current method displayed high sensitivity (LOD = 190 nmol L−1) and enhanced selectivity. As control, nanostructures including Cu7S4-Au, Cu7S4@S-MoS2 and Cu7S4-Au@M-MoS2 (M: multilayer) were also investigated, but showed low response to Hg(II), suggesting that both Au domains and active edge sites of monolayer MoS2 have crucial synergistic effects on the high-performance for recognition of Hg(II). Moreover, the developed method displays satisfied performance for the detection of Hg(II) in real samples, which indicates its potentials in practical applications.