Construction of a CQDs/Ag3PO4/BiPO4 Heterostructure Photocatalyst with Enhanced Photocatalytic Degradation of Rhodamine B under Simulated Solar Irradiation

A carbon quantum dot (CQDs)/Ag3PO4/BiPO4 heterostructure photocatalyst was constructed by a simple hydrothermal synthesis method. The as-prepared CQDs/Ag3PO4/BiPO4 photocatalyst has been characterized in detail by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet-visible spectroscopy, and photoelectrochemical measurements. It is demonstrated that the CQDs/Ag3PO4/BiPO4 composite is constructed by assembling Ag3PO4 fine particles and CQDs on the surface of rice-like BiPO4 granules. The CQDs/Ag3PO4/BiPO4 heterostructure photocatalyst exhibits a higher photocatalytic activity for the degradation of the rhodamine B dye than that of Ag3PO4, BiPO4, and Ag3PO4/BiPO4. The synergistic effects of light absorption capacity, band edge position, separation, and utilization efficiency of photogenerated carriers play the key role for the enhanced photodegradation of the rhodamine B dye.