Fabrication of silver vanadate quantum dots/reduced graphene oxide/graphitic carbon nitride Z-scheme heterostructure modified polyvinylidene fluoride self-cleaning membrane for enhancing photocatalysis and mechanism insight

In this work, 0D/2D/2D Z-scheme AgVO3 /RGO/C3N4 blending porous PVDF photocatalytic self-cleaning membrane (AgVO3/RGO/C3N4-PVDF) were successfully fabricated. The AgVO3/RGO/C3N4-PVDF photocatalytic membranes have high efficiency for removing tetracycline and could synergistically separate and photocatalytic kill the E. coli. [Display omitted] The enhancement of the self-cleaning ability of photocatalytic membranes and their degradation efficiency over tetracycline (TC) still remains a challenge. In this study, an alternative silver vanadate quantum dots (AgVO3 QDs) doped reduced graphene oxide (RGO) and graphitic carbon nitride (C3N4) nanocomposites modified polyvinylidene fluoride (PVDF) membrane (AgVO3/RGO/C3N4-PVDF) was successfully fabricated to enhance the photocatalytic activity. The AgVO3/RGO/C3N4 nanocomposites were functioned as the active component for the photocatalytic membrane. The unique Z-scheme heterostructure of AgVO3/RGO/C3N4 and the porous PVDF framework synergistically enhanced the separation and transport efficiency of photogenerated carriers and facilitated the interaction between the photocatalyst and the pollutant. As a result, the degradation efficiency of TC for the AgVO3/RGO/C3N4-PVDF reached 88.53% within 120 min, which was higher than those of the binary component membranes (64.8% for RGO/C3N4-PVDF and 79.18% AgVO3/C3N4-PVDF). In addition, AgVO3/RGO/C3N4-PVDF exhibited high permeability (1977 L·m−2·h−1·bar−1) and excellent antifouling activity. Under visible-light irradiation, the flux recovery rate (FRR) increased from 92.4% to 99.1%. Furthermore, AgVO3/RGO/C3N4-PVDF could reject 97.4% of Escherichia coli (E. coli) owning to its self-cleaning capacity, and eliminated the E. coli under visible-light irradiation trough the photogeneration of h+. This study highlights a highly efficient photocatalytic membrane based on a Z-scheme heterostructure, which may have a great potential application in practical wastewater treatment.