Topotactic synthesis and photocatalytic performance of one-dimensional ZnNb2O6 nanostructures and one-dimensional ZnNb2O6/KNbO3 hetero-nanostructures

This paper introduces one-dimensional ZnNb 2 O 6 /KNbO 3 hetero-nanostructures and one-dimensional ZnNb 2 O 6 nanostructures. These nanostructures are synthesized via in situ topotactic structural transformation reaction using the tunnel structure K 2 Nb 2 O 6 filiform crystal as precursor. Firstly, Zn 2+ ions intercalate into K 2 Nb 2 O 6 crystal by exchanging K + ions from the K 2 Nb 2 O 6 crystal with Zn 2+ from Zn(NO 3 ) 2 or Zn(CH 3 COO) 2 aqueous solution, to form two different Zn 2+ -exchanged samples, and then these Zn 2+ -exchanged samples topotacticly transform into one-dimensional ZnNb 2 O 6 /KNbO 3 hetero-nanostructures and ZnNb 2 O 6 nanostructures during heat-treatment. The formation reaction and structure of these samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), selected-area electron diffraction (SAED), and energy-dispersive spectroscopy (EDS). Photocatalytic experiments showed that one-dimensional ZnNb 2 O 6 /KNbO 3 hetero-nanostructures and ZnNb 2 O 6 nanostructures have excellent photocatalytic performance for the degradation of methylene blue (MB), rhodamine B (RhB), and methyl orange (MO). One-dimensional ZnNb 2 O 6 /KNbO 3 hetero-nanostructures and ZnNb 2 O 6 nanostructures are synthesized by Zn 2+ -exchange of tunnel structural K 2 Nb 2 O 6 fiber and topotactic structure transformation reaction.