Simultaneous preparation of silica and high purity porous graphene from palm oil fuel ash via single step method

Abstract

Palm oil fuel ash (POFA), an abundantly generated waste by-product of oil palm industry has been introduced as a raw material in this study for its prolific utilization and to cope with its environment threats. Due to its silica rich carbon-based composition, it has been used for the first time to produce both silica and few layer POFA derived porous graphene flakes (PDPGF) in a single step via chemical activation method. X-ray diffractometry analysis revealed broad peaks for silica and PDPG at diffraction angle of 22˚and 26˚ respectively. Scanning electron microscopy revealed the surface morphology with little agglomeration and flaky nature of graphene sheets. From high-resolution transmission electron microscopy, it was confirmed that there are 7 to 8 layers of graphene with interlayer spacing of 0.339 nm. Electron dispersive spectroscopy confirmed the presence of silicon and carbon (>98 wt%). Both silica and PDPGF give yields of 80% and 20% respectively.