A single step process to synthesize ordered porous carbon from coconut shells-eggshells biowaste

A novel method is used to synthesize ordered porous carbon from natural bio waste. Eggshells and coconut shells powder particles were used for synthesis of bio carbon. Eggshell particles were used as template as well as activating agent for synthesis of ordered porous carbon, while coconut shells act as a precursor. The synthesized activated carbon particles were characterized with the aid of X-ray diffraction analysis (XRD), Raman spectroscopy, Thermogravimetric analysis (TGA), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Surface area analysis. Adsorption capacity of synthesized ordered porous carbon was investigated with UV–vis spectroscopy. XRD results revealed that the optimum temperature for pyrolysis of eggshell-coconut shell mixture is 800 °C. XRD and Raman analysis confirmed the formation of amorphous carbon. It was observed that 1:1 ratio at 800 °C gave optimum results when compared with 1:2, 1:3 and 1:4 eggshells and coconut shells mixture. Brunauer–Emmett–Teller (BET) surface area and pore volume of 1:1 ratio at 800 °C were found to be 375.4 m² g⁻¹ and 0.2478 cm³ g⁻¹ respectively. The average pore size was found to be 2.64 nm for 1:1 ratio of eggshells-coconut shells mixture pyrolyzed at 800 °C. Morphology analysis confirms the formation of micropores and mesopores on the surface of carbon particles. The adsorption isotherms were well fitted with Langmuir isotherms. Maximum adsorption capacity was found to be 305.76 mg g⁻¹ for methylene blue adsorption on the surface of ordered porous carbon. (paper)