Photoelectrocatalytic degradation of rhodamine B pollutant with a novel zinc phosphate photoanode

Abstract

The present work evaluates the efficiency of Zn3(PO4)2 (ZnP) thin films photoanode for the removal of Rhodamine B (RhB) pollutant. ZnP has been electrodeposited on fluorine-doped tin oxide (FTO) substrate using the cathodic electrodeposition technique. The photoelectrochemical (PEC) properties of this material have been investigated using chronopotentiometry, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The photoanode was characterized by means of X-Ray diffraction (XRD) and scanning electron microscopy (SEM) which revealed that the structures and morphologies of the electrodeposited Zn3(PO4)2 films depended on the applied current densities and deposition times. The PEC activity of ZnP was investigated through the destruction of 10 mg/L of RhB aqueous solution containing 0.1 mol/L NaCl, 99 % of reduction was observed during 30 min of reaction time. Four consecutive experiments using the same photoanode have been carried out and the PEC activity was not reduced which signified the high stability of the elaborated ZnP. The obtained results have shown that the prepared photoanode exhibits photoactivity and can be used for the photo-assisted electrolysis for organics degradation in aqueous effluents.