Electrochemically synthesized Pt-MnO2 composite particles for simultaneous determination of catechol and hydroquinone

In this work we report the simultaneous determination of catechol (CC) and hydroquinone (HQ) at electrodeposited Pt-MnO2 particles on glassy carbon electrode. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) results revealed that spherical Pt and MnO2 particles deposited on GCE. Electrochemical impedance spectroscopy (EIS) studies showed that Pt nanoparticles in the Pt-MnO2 composite film help the facile transfer of electrons from MnO2 to the GCE; thereby it decreases the electron transfer resistance (Ret) of the film. The application of the Pt-MnO2 film for the electrocatalysis of CC and HQ was studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Well defined voltammetric peaks were obtained for a mixture of equal concentrations of HQ and CC in pH 7 with a peak potential separation of 0.12 V. The simultaneous determination of CC and HQ was done by DPV. The linear range of detection of CC is 15 μM to 0.447 mM and HQ is 3 μM to 0.481 mM. Simultaneous determination of HQ and CC in tap water samples has been studied. The film also detects HQ present in skin whitening cream. This report suggests that Pt-MnO2 composite is a promising material for electrocatalytic and electroanalytical applications.