Enhanced electrocatalytic nitrite determination using poly(diallyldimethylammonium chloride)-coated Fe1.833(OH)0.5O2.5-decorated N-doped graphene ternary hierarchical nanocomposite

Abstract

To develop simple and sensitive electrocatalytic technique for toxic nitrite determination is significantly important. Electrochemical nitrite sensor has attracted tremendous attention owing to its high sensitivity, selectivity and short response time. Here, we report the highly sensitive nitrite sensor based on poly(diallyldimethylammonium chloride) (PDDA)-coated Fe1.833(OH)0.5O2.5-decorated N-doped graphene (NG) ternary hierarchical nanocomposite (Fe1.833(OH)0.5O2.5/NG@PDDA). Differing from complicated synthetic routes for the reported ternary systems, the Fe1.833(OH)0.5O2.5/NG@PDDA composite can be effectively constructed by a facile one-pot hydrothermal method. The electrochemical performance of Fe1.833(OH)0.5O2.5/NG@PDDA composite film modified glassy carbon electrode was investigated by cyclic voltammetry and amperometric techniques. The experimental results indicate that synergistic effect of Fe1.833(OH)0.5O2.5 as catalytic center, NG as conductive platform and PDDA as nitrite adsorbent can significantly enhance the electrochemical response. The fabricated sensor exhibits the excellent analytical performance for nitrite detection linearly over two different concentration ranges, which are from 0.1 to 347μM and from 347 to 1275μM with a detection limit of 0.027μM (S/N=3). The value is very much comparable to the recent literature ones. Moreover, the proposed electrochemical sensor also shows good stability, reproductivity and excellent anti-interference ability against metal ions and electroactive species, and exhibits satisfactory recovery for detecting nitrite in drinking water.