Cu2O NPs decorated BiPO4 photo-catalyst for enhanced organic contaminant degradation under visible light irradiation

Abstract

The surface of BiPO₄ was decorated with Cu₂O nanoparticles (NPs) (hereafter designed as Cu₂O/BiPO₄) via an interfacial self-assembly method. The physical and photophysical properties of the Cu₂O/BiPO₄ hybrid photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray fluorescence spectrometry (XRF), UV-vis diffuse reflectance spectroscopy (DRS) and photo-electro-chemical (PEC). Compared with bare BiPO₄ and Cu₂O, the Cu₂O/BiPO₄ composites exhibited significantly enhanced photocatalytic activity for methylene blue (MB) degradation under visible light irradiation. The 5 wt% Cu₂O/BiPO₄ showed the highest photocatalytic activity under visible light irradiation, which was about 12.25 times that of BiPO₄. Significantly, the superior stability was also observed in the five cyclic runs. The Cu₂O/BiPO₄ hybrid photocatalysts exhibited dramatically enhanced photo-induced electron–hole separation efficiency, which was confirmed by the results of photocurrent measurements. On the basis of the experimental results and estimated energy band positions, the mechanism of enhanced photocatalytic activity was proposed.