Hydrothermal synthesized urchin-like nickel-cobalt carbonate hollow spheres for sensitive amperometric detection of nitrite

Abstract In this article, we present a facile and low-cost method to prepare urchin-like nickel-cobalt carbonate hollow spheres that display excellent electrooxidation of nitrite. The as-fabricated samples are characterized by XRD, SEM, TGA, and BET. The results confirm that the successful formation of nickel carbonate and cobalt carbonate at ratio of 1/2, and their entirely uniform hollow microspherical structure with an average pore size of 4 nm and a pore volume of 0.15 cm 3  g −1 . Moreover, the as-prepared nitrite sensor has a good electrochemical response with the linear range of 5–4000 μM and the detection limit of 0.002 μM under optimum conditions, respectively with the correlation coefficient of 0.999. The fabricated nitrite sensor also exhibited high sensitivity and good stability.