Cassava flour extracts solution to induce gelatin cross-linked activated carbon-graphene oxide composites: The adsorption performance of dyes from aqueous media

To enhance the performance of activated carbon (AC) for dyes removal, this study proposed a new composite of cassava flour solution extracts-cross-linked activated carbon and graphene oxide (named as AC-GO) to efficiently remove dyes from an aqueous solution. The designed routes involved creatively introducing cassava flour extracts solution (CES) to induce the conjugation and precipitation of the activated carbon and graphene oxide within a minute at a temperature of 60-100°C. The AC-GO composites were prepared from both powder and granulated activated carbon (PAC-GO and GAC-GO) and were characterized via several techniques such as Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), FTIR, N2 adsorption-desorption curves, etc... Phenomena prove that the carbohydrates, cyanide acid, protein, minerals, and sulfur group in CES play a role in the formation of intermolecular cross-linkage with small polar compounds in GO and AC during the thermal treatment process. Results of characterization demonstrated that thin GO films were coated on AC. Promotions of specific surface area after supporting GO compared to that of PAC and GAC were observed. The evaluation of their performance indicated that the methylene blue trihydrate (MB) was totally removed by AC-GO at a low concentration (10-50 mg/L). The relatively good performance for the removal of Direct Red 23 (DR23) by the composites was observed. The adsorption capacity of MB and DR23 by PAC-GO was 248.14 mg/g and 114.81 mg/g, respectively, while for MB and DR23 by GAC-GO, they were 222.72 mg/g and 66.80 mg/g, respectively.