Preparation and Characterization of Co3(PO4)2/Ag3PO4 Nanocomposites for Visible-Light Photocatalysis

In this study, Ag3PO4 nanoparticles (NPs), cobalt phosphate (Co-3(PO4)(2), CoP) nanosheets (NSs), and their composites (CoP/Ag3PO4) were synthesized via a facile chemical precipitation method. Their visible-light photocatalytic activities were compared and investigated. The structural, morphological, optical, and visible-light photocatalytic properties of the prepared samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), ultraviolet- visible (UV- Vis) diffuse absorbance and photoluminescence (PL) spectroscopies. We found that both the degradation rate and cyclical stability of the CoP/Ag3PO4 hybrids increased significantly under visible-light irradiation when methyl orange (MO) was used as the target with reference to single-phase Ag3PO4 NPs or CoP NSs. This suggests that CoP might play a cocatalyst role, which suppresses carrier recombination and provides a large number of photogenerated holes. Additionally, we also observed that the CoP/Ag3PO4 hybrids hardly degraded Rhodamine B (RhB), a cationic dye. This behavior might be attributed to the lower amount of dye molecule absorption because of a change in surface polarity. We thus present a new approach for the development of low-cost and visible-light responsive photocatalysts.