Phenol degradation using the mixed material clay/Fe immobilized on glass slides.

The mixed material clay/Fe was prepared and immobilized on glass slides and calcined at 550 and 750 °C. The calcined material X-ray powder pattern (XRD) diffractograms indicate that there is no intercalation of iron compounds inside the lamella clay. The experimental design revealed that the most suitable phenol degradation conditions were obtained using the material calcined at 750 °C in a pH 7 and 140 mg/L of hydrogen peroxide solution. The material MMAFe750 showed excellent performance as a catalyst for Fenton-like reaction; in 125 min, 50 % of phenol was removed in the absence of leaching-supported iron. These results indicate that the reaction occurs by a heterogeneous process. Furthermore, the material showed no loss of catalytic activity after five degradation studies. It was noted that the adsorption of phenol in the synthesized materials does not occur and the mixed material is strongly adsorbed onto glass slides.

Iron oxyhydroxide nanostructured in montmorillonite clays: Preparation and characterization.

Akaganéite is a very rare iron oxyhydroxide in nature. It can be obtained by many synthetic routes, but thermohydrolysis is the most common method reported in the literature. In this work, akaganéite-like materials were prepared through the thermohydrolysis of FeCl(3).6H(2)O in water and suspensions containing clay minerals. X-ray diffractometry (XRD), Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM) data show that the clays determine the crystal phase and size of the iron oxyhydroxide crystals. According to XRD and FTIR data, beta-FeO(OH) (akaganéite) is the main metal oxyhydroxide phase. Considering the small basal spacing (d(001)) displacement observed when comparing the XRD patterns of pristine clays with the composites containing beta-FeO(OH), the iron oxyhydroxide should be mostly located on the basal and edge surfaces of the clay minerals. UV-Vis electronic absorption spectra indicate that the preferred phase of the iron oxyhydroxide is determined by the nature of the clay minerals.