Controlled electrochemical synthesis of yttrium (III) hexacyanoferrate micro flowers and their composite with multiwalled carbon nanotubes, and its application for sensing catechin in tea samples

We report the hierarchical growth of yttrium (III) hexacyanoferrate (YHCF), having a shape that resembles that of rose flower petals on a glassy carbon electrode (GCE) modified with functionalized multiwalled carbon nanotubes. The modified GCE displays excellent electrocatalytic activity toward catechin (CA) oxidation. The morphology and impedimetric response of YHCF were optimized by controlling the number of depositing cycles. As-synthesized YHCF micro flower was characterized by thin film X-ray diffraction (XRD) and infrared (IR) spectroscopic methods, respectively. By taking the advantage of a template-free, surfactant-less, and simple procedure, YHCF micro flowers have been prepared. The sensitivity and low detection limit of functionalized multiwalled carbon nanotube (fMWCNT)/YHCF/GCE toward CA are 1.311 μA μM⁻¹ cm⁻² and 0.28 μM, respectively. Moreover, the fabricated GCE exhibits sufficient recovery for CA determination in green tea and oolong tea samples.