Enhanced electrocatalysis for the reduction of hydrogen peroxide at new multiwall carbon nanotube grafted polydiphenylamine modified electrode

A new modified electrode having multiwall carbon nanotube (MWNT) grafted with polydiphenylamine (PDPA) as electrocatalytic layer is fabricated. FESEM image of the modified electrode shows a different morphology indicating the grafting of PDPA over MWNT. This morphology is in quite contrast from the conventional bilayer MWNT/conducting polymer modified electrode. The multiwall carbon nanotube grafted polydiphenylamine (MWNT-gPDPA-ME) shows excellent electrocatalytic activity towards the reduction of hydrogen peroxide. The combined presence of MWNT and PDPA as a single unit provides better sensitivity than the bilayer configuration (MWNT/PDPA-ME). This modified electrode shows accelerated electron transfer at the interface with minimized surface fouling and surface renewability. The advantages of MWNT-g-PDPA-ME over the bilayer electrode are demonstrated with chronoamperometric studies. The amperometric response to H2O2. obtained at - 300 mV (vs. SCE) is rapid and highly sensitive as evident from the higher (2.83 x 10(-3) cm(3) mol(-1) s(-1)) rate constant for the diffusion reduction process.