Biomimetic synthesis of Ag₃PO₄-NPs/Cu-NWs with visible-light-enhanced photocatalytic activity for degradation of the antibiotic ciprofloxacin

1D Ag₃PO₄-NPs/Cu-NWs have been constructed to enhance visible-light-driven photocatalytic activity via biomimetic synthesis. Cu nanowires (NWs) were synthesized by a facile hydrothermal method. During the process of biomimetic synthesis, the porous PTFE film, which can mimic the transport process of cell membranes, plays an important role in controlling the transport speed of silver ions (Ag⁺) to decrease the reaction speed. Thus inhibition of the replacement reaction of Ag⁺/Cu and the uniform growth of Ag₃PO₄ nanoparticles (NPs) with a diameter of about 10 nm on Cu-NWs can be realized simultaneously. The diameter of Ag₃PO₄-NPs/Cu-NW is about 70 nm. Owing to the high electron transport of single crystal Cu-NWs, the free electrons in Ag₃PO₄ are transferred out to promote photogenerated electron-hole pair separation. The stability of Ag₃PO₄ NPs of the Ag₃PO₄-NPs/Cu-NWs was improved and the photodecomposition no longer occurred. Meanwhile, the band-gap of Ag₃PO₄ decreased to 2.07 eV after being coated on Cu-NWs and expanded the absorption scope of visible-light. In addition, the active species-trapping experiments indicated that the holes and O₂^- play important roles in the photocatalytic reactions. The novel Ag₃PO₄-NPs/Cu-NWs were used for the degradation of ciprofloxacin (CPFX) for the first time and showed high photocatalytic degradation performance. After visible-light irradiation for 15 min, the degradation rates of CPFX with pure Ag₃PO₄ NPs and AC_0.3 as catalysts were about 27% and 53%. In the end, the degradation efficiency of Ag₃PO₄-NPs/Cu-NWs was 6.07 times that of the pure Ag₃PO₄ NPs.