Three-dimensional Setaria viridis-like NiCoSe2 nanoneedles array: As an efficient electrochemical hydrazine sensor

Transition metal selenides are widely used in electrocatalysis on account of high electrical conductivity, good stability and low cost. In this study, using nickel-cobalt layered double hydroxide (NiCo-LDH) as precursor, a simple two-step method was used to prepare three-dimensional (3D) Setaria viridis-like NiCoSe2 nanoneedles arrays on nickel foam (NiCoSe2 NNA/NF). Benefiting from the abundant catalytic active sites provided by the 3D nanoneedles array structure, the covalent reciprocity between Ni, Co and Se can effectively facilitate the free movement of ions and electrons on the electrode surface. As a hydrazine sensor, the electrochemical performance of the NiCoSe2 NNA/NF was studied by cyclic voltammetry (CV) and other electrochemical techniques, which exhibits outstanding electrocatalytic performance. When the signal-to-noise ratio is 3 (S/N = 3), the sensitivity is 16170 μA mM−1 cm−2, the lower detection limit is 0.5 μM. It also shows well anti-interference and long-term stability. In addition, the successful applications in water environments samples also demonstrated the feasibility of the sensor. This method provides a new idea for the development of selenide-based electrochemical sensors.