Synthesis and characterization of CuO-NiO nanocomposite for dye degradation and electrochemical sensing of dopamine

•Metal nanoparticles and composite were synthesized using combustion method.•Different spectral methods were used for examining metal NP and NC.•The photocatalytic activity of CuO-NiO NC was studied by using methylene blue dye towards various parameters•The electrochemical detection of dopamine was examined using a cyclic voltammeter and a modified CuO-NiO GCE. In this study, CuO-NiO nanocomposite (NC) was synthesised via simple combustion method. The prepared NC was characterized by XRD, FTIR, UV-Visible, PL, EIS, SEM, TEM and EDAX. XRD data is matched with the standard JCPDS 5-661 and 78-429, which correspond to CuO and NiO respectively. FT-IR spectrum exhibits the existence of metal-oxygen bonding in CuO-NiO NC. Optical energy band gap of CuO-NiO NC was found to be 3.12 eV. PL spectrum excited at 329 nm shows an emission peak at 490 nm. The photodegradation of CuO-NiO NC on MB dye was examined under UV light irradiation. CuO-NiO NC acts as a good photocatalyst compared to individual metal oxide NP. At low concentrations of dopamine, CuO-NiO NC exhibits very good electrochemical sensing. The analytical profile of composite electrode shows long linear range, sensitivity and LOD of 1.0-6.0 µM−1L−1, 0.179µAµM−1cm−2, and 0.033µmol/L. [Display omitted]