Abstract

This paper reports the beneficial effects of gold nanoparticles (GNPs) on the deposition, electrochemistry and electrocatalysis of Prussian Blue (PB) on a glassy carbon electrode modified with a bucky gel (BG) consisting of carbon nanotubes (CNTs) and ionic liquid (IL). The electrodeposition of PB nanoparticles was accomplished on the BG/GC electrode in the absence and presence of GNPs and the effect of GNPs on the electrochemical properties of PB was investigated. The PB-GNPs/BG/GC electrode showed a higher PB surface concentration and lower formal potential, as compared with the PB/BG/GC electrode. The calculated surface concentration value of PBwas 1.1x10(-8) mol cm(-2), showing that the deposition efficiency of PB was enhanced by 2.7 fold, and the formal potential decreased from 0.198 to 0.183 V. The apparent diffusion coefficient of K+ (2.28 x10(-10) cm(2) s(-1)) was enhanced by a factor of similar to 15 compared with that in the absence of GNPs. Although electron transfer rate (k(s)) of the PB-GNPs/BG/GC modified electrodes (1.60 s(-1)) decreased by 30, the sensitivity toward H2O2 reduction was greatly increased (about four times) and the dynamic range for H2O2 detection was prolonged over three orders of magnitude. On the other hand, GNPs improved the stability of the PB modified electrode. Compared to other H2O2 sensors, the PB-GNPs/BG/GC electrode could detect H2O2 in a wide dynamic range of 9.16 x 10(-6) to1.43 x 10(-1) M with a very high sensitivity. (c) 2020 Elsevier B.V. All rights reserved.