Synthesis and application of carbon cryogel beads using coconut husk for dye removal

Abstract

The production cost of carbon cryogels has been reduced by using alternative starting materials as precursor such as wattle tannin and furfural. In this study, a novel carbon cryogel beads were synthesized from low cost and abundant agricultural waste, coconut husk. Lignin was extracted and the percentages of lignin yield and lignin degradation were 27.63% and 13.39wt% respectively which were considered low due to the low operating temperature of lignin extraction in this study. The lignin extracted was then mixed with formaldehyde, sodium hydroxide, ethanol, and distilled water to undergo sol-gel polycondensation, followed by freeze drying and pyrolysis in an inert atmosphere to produce carbon cryogel beads. The adsorption of methyl blue on carbon cryogel beads increased with increasing with pH, initial dye concentration and temperature.