The effect of support on the structure and photocatalytic activity of ternary ZnO-ZnFe2O4/palygorskite composite photocatalysts

摘要

The ternary ZnO-ZnFe2O4/palygorskite composite photocatalysts were fabricated via a solvothermal method followed by thermal treatment. The structure, morphology and photoelectric performances of samples were characterized, and the results indicated that ZnO/ZnFe2O4 nanoparticles with size of 25-30 nm were adequately anchored on the palygorskite fibers surface. Compared with ZnO, ZnFe2O4, ZnO/ZnFe2O4 and ZnO/palygorskite, the ZnO-ZnFe2O4/palygorskite composite photocatalysts exhibited significantly improved photocatalytic activity in degradation of methylene blue (MB). Especially, the optimal photocatalyst (ZF1.5) displayed the highest photocatalytic activity, achieving 99.68% and 99.48% degradation efficiency after 90 min of UV-vis (350 <= lambda <= 780 nm) and 100 min of visible-light (lambda >= 420 nm) irradiation, respectively. The photocatalysis degradation process matched well with the Langmuir-Hinshelwood kinetics. The obtained improvement of photocatalytic activity was ascribed to the synergetic effect of superior visible-light utilization; effective charge carrier separation and palygorskite support effect (optimize nanoparticles dispersibility, developed mesoporous structure, enlarge specific surface area and increase adsorption capacity). (C) 2019 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.