Construction and Mechanism of Ag3PO4/UiO-66-NH2 Z-Scheme Heterojunction with Enhanced Photocatalytic Activity

A new type of Ag3PO4/UiO-66-NH2 Z-scheme heterojunction nanocomposite with visible light catalytic activity was successfully prepared. The synthesis of the composite was confirmed by XRD, FT-IR, SEM, TEM, EDS, XPS. The Ag3PO4/UiO-66-NH2 Z-scheme heterojunction can effectively improve the utilization of visible light. The optimal Ag/U/1/4 composite has the highest degradation efficiency for methylene blue (MB, 30 mg/L) in 90 min (80%) and Norfloxacin (NOR, 10 mg/L) in 150 min (85%). The decrease of Nyquist radius and the enhancement of photocurrent response indicated that the combination of photogenerated electron–hole pair in Ag3PO4/UiO-66-NH2 composite material is significantly inhibited. N2 adsorption–desorption and zeta potential results indicated that biggish specific surface area and negative zeta potential value are more favorable for the adsorption of the cationic dye MB. The cyclic test verified the good stability of Ag3PO4/UiO-66-NH2 heterojunction material. Furthermore, the photocatalytic degradation mechanism of MB was discussed by introducing different traps to inhibit the possible active substances in the degradation process. This work testified that an efficient photocatalytic composite based on metal–organic frameworks can be used for the degradation of pollutants.