Synthesis and characterization of sulfate and dodecylbenzenesulfonate intercalated zinc–iron layered double hydroxides by one-step coprecipitation route

Inorganic sulfate- and organic dodecylbenzenesulfonate (DBS)-intercalated zinc–iron layered double hydroxides (LDHs) materials were prepared by one-step coprecipitation method from a mixed salt solutions containing Zn(II), Fe(II) and Fe(III) salts. The as-prepared samples have been characterized by X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), low-temperature nitrogen adsorption, scanning electron microscopy (SEM), inductively coupled plasma emission spectroscopy (ICP), and Mössbauer spectroscopy (MS). The XRD analyses demonstrate the typical LDH-like layered structural characteristics of both products. The room temperature MS results reveal the characteristics of both the Fe(II) and Fe(III) species for SO42−-containing product, while only the Fe(III) characteristic for DBS-containing one. The combination characterization results and Rietveld analysis illustrate that the SO42−-containing product possesses the Green Rust two (GR2)-like crystal structure with an approximate chemical composition of [Zn0.435·FeII0.094·FeIII0.470·(OH)2]·(SO42−)0.235·1.0H2O, while the DBS-containing one exhibits the common LDH compound-like structure. The contact angle measurement indicates the evident hydrophobic properties of DBS-containing nanocomposite, compared with SO42−-containing product, due to the modification of the internal and external surface of LDHs by the organic hydrophobic chain of DBS.

For Zn2+–Fe2+–Fe3+ GR2(SO42−), according to the derived chemical formula, Fe3+ was arranged at 1a (0, 0, 0) position, while all Zn2+ were in 2d position with the occupancy 0.645, and the left part of 2d positions were taken by Fe2+/Fe3+.Figure optionsDownload as PowerPoint slide