Phosphomolybdate@poly(diallyldimethylammonium chloride)-reduced graphene oxide modified electrode for highly efficient electrocatalytic reduction of bromate

Abstract Phosphomolybdate ([PMo 12 O 40 ] 3− or PMo 12 ) was adsorbed onto a poly(diallyldimethylammonium chloride) functionalized reduced graphene oxide (rGO-PDDA) modified glassy carbon electrode (GCE). Compared to monolayer formation of PMo 12 on a bare GCE, the rGO-PDDA electrode has a significantly increased loading of PMo 12 , due to its much larger surface area. The presence of positively charged PDDA also favors the adsorption of negatively charged PMo 12 and enhances the stability of the modified electrode. The fabricated electrode (PMo 12 @rGO-PDDA/GCE) was characterized by scanning electron microscopy as well as energy dispersive X-ray, Raman and FT-IR spectroscopies and applied to the electrocatalytic reduction of bromate. Cyclic voltammetry showed that PMo 12 @rGO-PDDA/GCE exhibits high electrocatalytic performance and good stability for the reduction of bromate. A wide linear current vs. bromate concentration response (0.02–10 mM) was achieved with excellent sensitivity (454 μA cm −2  mM −1 ). The kinetics for the electrocatalytic reduction of bromate and the number of electron involved were evaluated using the rotating disk electrode method.