Superior dye degradation for wastewater treatment based on nanocomposites of cerium oxide, gadolinium oxide and graphene oxide

Abstract

Despite the significant Progression in nanocomposites (NCs) tailoring for ecological purposes, optimizing NCs for water treatment is still a challenge. Moreover, organic coloring (dyes) agents like Congo red (CR) and methylene blue (MB) were included which have carcinogenic effects. In this regard, photo-catalytic activity utilizing NCs for organic pollutants (dyes) removal is a great concern due to its viability and low cost. In this regard, a combination of nanocomposites including cerium Oxide (CeO2), gadolinium oxide (Gd2O3), and graphene oxide (GO) could be suggested. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) were utilized for characterization in addition to EDX, and electron microscopes (TEM, and FESEM). TEM micrograph exhibits TNC as scattered lanthanides oxides (CeO2, and Gd2O3) grains upon GO sheets. It shows a clear decline in the average size to reach 25 nm for CeO2, and 40 nm for Gd2O3. Also, FESEM reports that GO reduces the lanthanide oxides aggregation tendency in TNC, besides forming shallow pores within its rough surface. Regarding the thermal study, It is clear that activation energy (E*) is the almost equal enthalpy of activation (ΔH). It could refer to the presence of the tested composition at a higher degree of temperature (thermally stable). Nano-composite powders exhibited improvement in photo-catalytic efficiency and inhibition of photo-corrosion as compared with pure lanthanide oxides. The MB degradation potential of CeO2/Gd2O3/GO drops from 94.4 % in the first usage to 82.1 % in the fifth.