Cost-effective Synthesis of CeO_2-SiO_2 Based on Oil Palm Leaves for the Removal of Toxic Compounds

Using cerium nitrate as a cerium source and oil palm leaves (OPL) as the main silica (SiO_2) source, CeO_2–SiO_2(OPL) powder was synthesized via calcination at 900 °C under air conditions. An X-ray diffraction analysis of the as-prepared product revealed the formation of CeO_2 supported on cristobalite SiO_2 along with some other minor element oxides. The Fourier transform infrared spectra showed peaks attributable to the Si–O–Si and Ce–O bonds of the binary oxide. According to a scanning electron microscopy analysis, the solid materials produced via calcination were in aggregated form. The solid, which was easily powdered by grinding in a mortar, was studied for the removal of methylene blue (MB) and phenol compounds from aqueous solution. The results showed that the CeO_2–SiO_2(OPL) material could remove MB up to 62.6% but was ineffective for phenol removal under various conditions.