Preparation, performance and mechanism of p-Ag3PO4/n-ZnO/C heterojunction with IRMOF-3 as precursor for efficient photodegradation of norfloxacin

Abstract

Ag3PO4/ZnO/C photocatalyst with p-n heterojunction has been prepared by ultrasound assisted precipitation based on ZnO/C obtained by pyrolysis using isoreticular metal-organic frameworks (IRMOF) as precursor. The results show that Ag3PO4 uniformly dispersed on the pores and surface of the porous ZnO/C, and the whole catalyst is floss cake-like. ZnO/C and Ag3PO4 are successfully composited and possess good photocatalytic activity and stability. The degradation rate of norfloxacin by Ag3PO4/ZnO/C can reach 89.48% under the best reaction conditions, which is 2.97 times than that of pure Ag3PO4, and Ag3PO4/ZnO/C also shows better photocatalytic performance and reusing stability than Ag3PO4. The results of the active species capture experiment confirms that ⋅O2− and holes (h+) play major roles in the process of degrading norfloxacin by Ag3PO4/ZnO/C under visible light irradiation. The main reason for the enhanced photocatalytic activity and stability of Ag3PO4/ZnO/C is that the introduction of ZnO/C has widened the light adsorption range and reduced the solubility of Ag3PO4 in Ag3PO4/ZnO/C. At the same time, the excellent electron transfer capability of graphite in ZnO/C and the p-n heterojunction formed between Ag3PO4 and ZnO can promote the electrons migrating from Ag3PO4 to ZnO/C, effectively inhibiting the photocorrosion of Ag3PO4.