Investigation on the synthesis and photocatalytic activity of activated carbon-cerium oxide (AC-CeO2) nanocomposite

Nano-sized photocatalyst cerium oxide (CeO2) particles and activated carbon-cerium oxide (AC-CeO2) composite are prepared by facile hydrothermal technique. Their properties are analyzed by subjecting them to characterization techniques such as powder X-ray diffraction (PXRD), high-resolution scanning electron microscopy (HRSEM), energy dispersive X-ray analysis (EDX), high-resolution transmission electron microscopy (HRTEM), Fourier transform infra-red spectroscopy (FTIR) and Raman spectroscopy. The photocatalytic activity of the prepared samples is monitored by UV-visible spectrophotometer. The PXRD, FTIR, Raman and EDX analyses confirm the formation of CeO2 nanoparticles. The PXRD studies revealed that the CeO2 nanoparticles and AC-CeO2 nanocomposite have face centered cubic structure. The average crystallite size of CeO2 nanoparticles and AC-CeO2 nanocomposite, estimated using Scherrer formula, is found to be 21 nm and 7 nm. The HRSEM images show that the CeO2 nanoparticles and AC-CeO2 nanocomposite have spherical morphology and some agglomeration. The HRTEM images strongly confirm spherical morphology of both CeO2 nanoparticles and AC-CeO2 nanocomposite. The particle size of the CeO2 nanoparticles and AC-CeO2 nanocomposite are in the size range 20-30 nm and 7-15 nm, respectively. The selected area electron diffraction (SAED) patterns reveal that both samples are polycrystalline in nature. The photocatalytic activity of the synthesized CeO2 nanoparticles and AC-CeO2 nanocomposite is measured by degrading methylene blue dye under solar radiation. The photocatalytic activity study shows that the AC-CeO2 nanocomposite has a degradation efficiency of 94% in 1 h for methylene blue, which is remarkably high when compared to that of CeO2 nanoparticles.