High photocatalytic capacity of porous ceramic-based powder doped with MgO

Abstract

To purify water at low cost for our daily life, the effect of ceramic-based (mullite–cristobalite) and (mullite–zircon) powders doped with different amounts of magnesium oxide (MgO) (10 and 20 wt%) was studied. These compounds are made of a local raw material DD3 with addition of zirconia (ZrO2) to create an open porosity. The powders were prepared by the traditional mixing method with the help of an automated crushing. The effect of MgO doping on structural, morphological and photocatalytic properties of the material was studied by various analytical techniques such as X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, infrared, and UV–visible spectrometry. The results of XRD proved that there was a deformation in the crystal structure of the two types of ceramics after addition, which resulted in a shift of the spectra to the right, while SEM proved the presence of pores with a larger size as the proportion of MgO increases. The chemical composition of the basic components of the ceramic compounds as well as the additive was confirmed with EDS and IR spectra. The final results show that ceramics with added zirconia (DD3Z) and doped with 10% of MgO have a better photocatalytic efficiency than ceramics without zirconia. This important effect could be related to the higher rate of porosity, which provides a more active surface. The 10% MgO content showed a high photoactivity of 77.33% in only 15 min. The maximum hydrolysis rate obtained with Orange II was 92.95% after a period of 45 min with DD3Z/MgO powders.