Novel Platycladus orientalis–shaped Fe-doped ZnO hierarchical nanoflower decorated with Ag nanoparticles for photocatalytic application

Abstract

Abstract The Ag/Fe-doped ZnO composites were designed by controllable intergration of the three strategies of hierarchical assembly, Fe doping, and Ag loading. The 3D Fe-doped ZnO hierarchical nanoflowers were firstly constructed with Platycladus orientalis–shaped petals via a hydrothermal method, and then Ag nanoparticles were anchored on the surface of Fe-doped ZnO nanoflowers through impregnation/reduction of silver nitrate solution. The samples were characterized by using XRD, SEM, TEM, HRTEM, XPS, Raman spectra, BET, UV–vis DRS, PL, EIS, Mott-Schottky plots, and photocurrent response. The results showed that Fe doping increased BET surface area and oxygen vacancies of ZnO, Ag loading produced the LSP absorption at ~530\xa0nm, Fe doping and Ag loading together extended the visible light absorption and facilitated the separation of photogenerated carriers, which favors photocatalytic activity of ZnO. The maximum degradation efficiency of 92.3% for MO was achieved after visible light irradiation for 80\xa0min when the feed atom ratio of Fe to Zn was 1.2% and Ag loading was 4\xa0wt% of Fe-doped ZnO. Four cycle tests had little effect on the morphology and structure of Ag/Fe-doped ZnO, suggesting good cycling stability. The photocatalytic mechanism was elucidated based on the scavenger experiments and energy bands alignment.