One pot synthesis of ZnO-CuO nanocomposites for catalytic peroxidase like activity and dye degradation

Abstract

In this study, we report a low temperature chemical decomposition method for the synthesis of ZnO-CuO nanocomposites from ZnAl-layered double hydroxides (ZnAl-LDHs) supported copper terephthalate based metal organic frameworks [Cu-(BDC) MOFs]. The Cu-(BDC) MOFs arrays on the surface of ZnAl-LDHs nanosheets are obtained via in situ nucleation and directed growth from the terephthalate (BDC) anion intercalated ZnAl-LDHs. Cu(II) ion coordinates with BDC ligand in a bidentate bridging fashion to form Cu-(BDC) MOFs. The as prepared Cu-(BDC) MOFs are strongly and uniformly anchored onto the surfaces of ZnAl-LDHs. Decomposition of the resultant ZnAl-LDH supported Cu-(BDC) MOF precursor in alkaline solution for 24 h leads to the formation of ZnO-CuO nanocomposites. The structures and morphology of the nanocomposites are discussed with the results of scanning electron microscopy (SEM), transmission electron microscopy (TEM) combined with selected area electron diffraction (SAED) images, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). The resulting ZnO-CuO nanocomposites show peroxidase like catalytic activity towards orthophenylene diamine oxidation (OPDox) and rhodamine 6 G (R6 G) dye degradation.