Photo-electrochemical degradation of rhodamine B using electrodeposited Mn3(PO4)2.3H2O thin films

Abstract

Mn3(PO4)2·3H2O thin films have been grown using the cathodic electrodeposition method. The samples were characterized in terms of structural, morphological, optical and photo-electrochemical characteristics using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) combined with energy dispersive X-ray spectrometer (EDX), mott-Schottky and gap energy determination and electrochemical impedance spectroscopy (EIS), respectively. The photo-electrocatalytic performance of the resulting electrode has been performed towards the decomposition of rhodamine B (RhB). The achieved results have indicated that the decomposition attained was 95%, while the highest Chemical oxygen demand value was 79% after 25 min of reaction time, the efficiency of the operation was attributed to the creation of OH° and holes oxidizing species. The Mott-Schottky investigation has revealed the n-type conduction of Mn3(PO4)2·3H2O and EIS results are modelled to an equivalent circuit by using the Zview software consisting of a pair of resistors in parallel with a CPE. Moreover, the prepared thin films exhibit excellent stability for 4 cycles, rendering them a viable candidate for the decomposition of organic pollutants in aqueous solutions.