Enhanced electrocatalytic oxidation activity of platinum-poly(methylene blue) as a sensitive sensor for ammonia–nitrogen detection

To achieve highly effective electrochemical determination of ammonia–nitrogen in the aqueous environment, in this work, based on the great electrocatalytic activities of platinum-poly(methylene blue) (Pt-PMB) composites for ammonia oxidation reaction, one new sensing electrode was constructed based on Pt-PMB for ammonia–nitrogen detection. PMB film was loaded on the surface of Ni foam (NF), and then, Pt film was covered on the PMB film, achieving a self-supported Pt-PMB-NF electrode. Under optimum conditions, prepared Pt-PMB-NF was analyzed via scanning electron microscopy (SEM) and element map and X-ray photoelectron spectroscopy (XPS), and the sensing performances including sensitivity, the limit of detection, selectivity and stability were measured via cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques and exhibited great results. In addition, the recovery of real samples indicated that this Pt-PMB-NF electrode showed great potential for practical application.