Synthesis of nanocubic shape controlled Gold-Prussian blue nanocomposite for enhanced electrocatalytic hydrazine oxidation

Abstract

• A facile wet chemical method used for the synthesis of nano cubic shape controlled Au-PB-NCs. • Au-PB-NC/GCE shows 13 times higher catalytic current density of hydrazine than pristine PB-NCs. • The sensitivity of Au-PB-NCs/GCE is 111 μA.cm −2 μM −1 with LOD of 0.709 µM for sensing of hydrazine. Herein, we report for the first time, facile chemical synthesis of gold nanoparticles embedded in nano-cubic shaped prussian blue (Au-PB-NCs). To understand the role of gold nanoparticles (AuNPs) present in the Au-PB-NCs, the same chemical method is used without involving gold precursor solution for pristine prussian blue nanocubes (PB-NCs). For the proof-of-concept experiment, both Au-PB-NCs and PB-NCs are modified on glassy carbon electrodes (it is called as Au-PB-NCs/GCE and PB-NCs/GCE respectively) to study the electrocatalytic activity of hydrazine molecules as a model system. The exact size of the PB-NCs and the nature of the distribution of AuNPs into the Au-PB-NCs matrix are confirmed by high-resolution transmission electron microscopy (HR-TEM) and high-angle annular dark-field scanning transmission electron microscopic (HAADF-STEM) analysis. X-ray diffraction (XRD) and X-ray photon electron microscopy (XPS) results reveal that the PB-NCs has high crystalline and the oxidation state of Au is Au 0 and Au + in Au-PB-NCs. Compared with PB-NCs/GCE, the Au-PB-NCs/GCE showed higher redox current density and improved charge transfer kinetics in electrochemical measurements. Remarkably, it exhibits higher electrocatalytic oxidation current and excellent amperometric response with the linear range of 0–40 µM for hydrazine molecule when compared with PB-NCs/GCE. The calculated low detection limit and sensitivity value of Au-PB-NCs/GCE is 0.709 µM and 111 µA. cm −2 . µM −1 , respectively, which are comparable with reported literature. The selectivity and stability of electrooxidation of hydrazine molecule on fabricated Au-PB-NCs/GCE platform is investigated by amperometric method. The obtained results clearly indicate that Au-PB-NCs/GCE has excellent stability and selectivity towards hydrazine sensing without the impact of other interference. Also, the developed Au-PB-NCs/GCE sensor platform is applied to the real water samples analysis and showed the results of good recovery, reproducibility and repeatability, which implies its feasibility for realistic application in hydrazine estimation.