Ni nanosheets evenly distributed on MoS2 for selective electrochemical detection of nitrite

Abstract

A glassy carbon electrode modified by composite material consisting of molybdenum disulfide nanosheets and nickel nanosheets (Ni/MoS 2 electrode) was prepared for electrochemical detection of nitrite. Ni/MoS 2 was characterized by energy dispersive X-ray spectroscopy, scanning electron microscopy, Raman spectroscopy and X-ray diffraction. Most of MoS 2 nanosheets had lateral dimensions less than 150 nm, and the nickel nanosheets were slightly smaller, which were covered on the surface of MoS 2 nanosheets evenly. The electrochemical method was used to characterize and study the electrochemical behaviors of Ni/MoS 2 and its responses to nitrite. Under the optimized conditions, the prepared Ni/MoS 2 electrode showed good detection performances and stability, with a detection range of 5–800 μM, and a detection limit of 2.48 μM (S/N = 3). In addition, by detecting nitrite in tap water, the practical applicability of the electrochemical sensor was verified. • Nickel nanosheets were covered on the surface of MoS 2 nanosheets evenly. • The combination of nickel and MoS 2 improved the selectivity and sensitivity of electrochemical detection of nitrite. • The Ni/MoS 2 electrode displayed good reproducibility and high stability during nitrite detection. • The Ni/MoS 2 electrode successfully used for the detection of nitrite in tap water.