Facile synthesis, characterization and photocatalytic performance of Zn3(PO4)2 platelets toward photodegradation of Rhodamine B dye

In this study, we have successfully prepared the zinc phosphate Zn3(PO4)2 through aqueous precipitation using PEG (Polyethylene glycol) as surface active agent. The compound was analyzed by X-Ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-Ray analysis (EDS). The diffraction profiles showed a highly crystallized sample with dimensions of 3 μm. Rietveld refinement confirmed the pure monoclinic C2/c zinc phosphate phase. The SEM images showed platelet faceted morphology with different orientations and a crystal growth mechanism has been proposed. The photocatalytic experiments were carried out using Rhodamine B (RhB) as a model pollutant; the UV-visible spectrometry was used to analyze the evolution of dye degradation. The obtained experimental results showed that the Rhodamine B dye degradation efficiency is significantly dependent on different physico-chemical conditions including catalyst loading, pH and dye concentration. Furthermore, the zinc phosphate photocatalyst was found to be fairly photostable during four regeneration cycles. Finally, a photocatalytic mechanism was proposed based on the active species trapping experiments.