Facile synthesis of antimony oxide/nickel antimonate nanorods with highly-efficient sensing performance for Co ions detection

The antimony oxide/nickel antimonate nanorods were prepared via a simple hydrothermal route using polyvinyl pyrrolidone (PVP) as the surfactant. The composite nanorods are composed of orthorhombic Sb 2 O 3 and tetragonal NiSb 2 O 6 phases, and have a length of longer than 1 μm, diameter of around 80 nm. The formation and growth of the antimony oxide/nickel antimonate nanorods were analyzed systematically by adjusting the PVP concentration, reaction temperature and reaction time. Glassy carbon electrode was modified by the antimony oxide/nickel antimonate nanorods for Co ions detection. There is an anodic peak at +0.61 V at the antimony oxide/nickel antimonate nanorods-modified electrode in 1 mM Co 2+ solution with 0.1 M KCl. The optimum adsorption sites for Co adsorption on the antimony oxide/nickel antimonate nanorods were identified by density functional theory (DFT) calculation. The optimized pH, deposition time and potential, standing time for Co 2+ detection are pH = 7, 120 s, −1.5 V and 40 s, respectively. The linear range and detection limit are 0.001–1000 μM and 0.12 nM, respectively. The antimony oxide/nickel antimonate nanorods-modified electrode demonstrates good sensing performance for detecting Co 2+ which can potentially be applied to detect Co 2+ ions in liquid environment.