Preparation of SnS/MWCNTs chemically modified electrode and its electrochemical detection of HO.

Considering the importance of hydrogen peroxide (HO) rapid detection, a SnS/MWCNTs composite was prepared by loading tin disulfide (SnS) nanoparticles on a three-dimensional conductive network composed of multi-walled carbon nanotubes (MWCNTs). The obtained SnS/MWCNTs composite was used as the modified material to prepare a chemically modified electrode (CME), which was used for the rapid detection of HO. The morphology and structure of the obtained samples were characterized and analyzed by scanning electron microscopy, X-ray diffraction, and energy-dispersive spectroscopy. The electrochemical performance of the modified electrode was researched by cyclic voltammetry, amperometric i-t curves, and AC impedance techniques. The results show that SnS nanoparticles with a size of about 33 nm are evenly dispersed on the surface of MWCNTs. The obtained SnS/MWCNTs-CME has a strong current response to HO: it has a good linear relationship during the range of 0.248 ~ 16.423 mmol L, and its linear regression equation is I (mA) = (-0.94 ± 0.05) × 10 + (- 0.43 ± 0.06) × 10c (mmol L) (R = 0.997) with a sensitivity of 87.84 μA mmol L cm. The corresponding detection limit is 1.04 μmol L (S/N = 3). At the same time, the SnS/MWCNTs-CME has good selectivity, reproducibility, and stability. Graphical abstract Uniformly distributed SnS/CNTs composite is used to prepare a chemically modified electrode for HO detection. The prepared electrode has a strong electrochemical response to HO due to the excellent conductivity and support of CNTs. And the SnS/CNTs electrode shows high sensitivity and selectivity for the electrochemical detection of HO.