Influence of co-electrodeposited Gold particles on the electrocatalytic properties of CoHCF thin films

Abstract

The electrochemical modification of solid electrodes with metal hexacyanoferrate thin films for enhancing the interfacial properties has created interest for over the past three decades. The preparation of Prussian blue (PB) Au nano composites for the enhancement in the electrocatalytic properties of PB on glassy carbon electrode has been reported by us. The incorporation of Au nano particles in Cobalt hexacyanoferrate (CoHCF) films on Glassy carbon by co-electrodeposition is expected to benefit its interfacial electron transfer properties. The present work describes the effect on the interfacial properties by incorporated Au particles in CoHCF (CoHCF(Au)) modified electrodes. The CoHCF(Au) modified electrodes were characterized by UV-Vis spectrophotometry, Cyclic Voltammetry, AC Impedance, FE-SEM etc., Influence on the electrocatalytic properties of CoHCF(Au) films have been explored by performing two important reactions i) Hydrazine elecrtro-oxidation ii) Oxygen evolution reaction. Our results reveal that CoHCF(Au) modified GC electrode perform better in terms of charge transport in the redox film and also for the electrooxidation of hydrazine in comparision with simple CoHCF modified electrodes. By using the current-transient technique (chrono method i vs t curve) the hydrazine diffusion coefficient (D0) were calculated. Diffusion coefficient of hydrazine was approximately three times higher on CoHCF(Au) electrode, 9.5×10−5 cm2 s−1 compared with simple CoHCF modified electrode, 3.3× 10−5 cm2 s−1. Similarly, we also discuss results which reveal that CoHCF(Au) electrodes enhances electrocatalytic activity in splitting water to oxygen in 0.1M NaOH solution compared to simple CoHCF and Au deposited on GC electrodes.