A new approach was developed for the green synthesis of ZnO-SiO2 composite and Zn2SiO4 using zinc nitrate and sustainable silica precursor, oil palm (Elaeis guineensis) leaves (OPL). The products were synthesized at two different reaction temperatures through calcination in an open-air furnace at 500 and 1000 °C, respectively, and further identified with an X-ray diffractometry (XRD) analysis. The composite indicated by the presence of peaks at 2θ = 31.7°, 34.4°, 36.3°, 47.6°, 56.6°, and 62.9°, corresponds to ZnO and also revealed amorphous SiO2 at 2θ = 21°. Conversely, Zn2SiO4 was acknowledged at 2θ 25.6°, 31.50°, 34.0°, 39.5°, 48.9°, 56.5° and 65.6°, with crystalline silica at 2θ = 21.9°. The results showed the morphology of both products exhibited similar agglomeration based on scanning electron microscopy (SEM) analysis. Both products (ZnO-SiO2 composite and Zn2SiO4) possessed the capacity to degrade methylene blue (MB) under sunlight irradiation with efficiency of 85.9% and 69.3%, respectively.
ZnO-SiO2 and Zn2SiO4 Synthesis Utilizing Oil Palm Leaves for Degradation of Methylene Blue Dye in Aqueous Solution