Preparation and Characterization of Shiitake Mushroom-Based Activated Carbon with High Adsorption Capacity

The potential of utilizing shiitake mushroom as feed stock for the preparation of activated carbon by chemical activation method with K ₂CO ₃ was explored. The prepared materials were characterized by thermogravimetric analysis, N ₂ adsorption–desorption analysis, scanning electron microscope, Fourier transform infrared spectrometer, X-ray diffraction and Raman spectra. The activation mechanisms were proposed with the aid of thermogravimetric analysis. X-ray diffraction and Raman analysis indicated that the activated carbon was amorphous macroscopically. The influences of activation temperature, mass ratio of K ₂CO ₃/shiitake mushroom, activation duration, heating rate and material mixed mode on the yield, porosity and surface morphology of the activated carbon were investigated in detail. The synthesized activated carbons was predominantly microporous having a specific surface area of 2330 m²/g, and the optimal process conditions were activation temperature of 800 ^∘C, mass ratio of K ₂CO ₃/shiitake mushroom of 1.5, activation duration of 180 min, heating rate of 5 ^∘C/min and mixed mode of impregnation. Addition to high surface area, it also exhibited a high iodine number adsorption capacity of 1432 mg/g and methylene blue adsorption capacity of 872 mg/g, which are far higher than the adsorption capacities reported in the open literature. These results demonstrate that the synthesized activated carbon could be utilized for variety of industrial applications.