Green Preparation and Environmental Application of Porous Carbon Microspheres

Porous carbon microspheres (PCM) show bright application prospects in the fields of adsorption, supercapacitors, hydrogen storage, catalysis and sustained release. In this work, PCM were prepared by properly designed hydrothermal and activated processes using waste peanut shell as raw material. PCM maintained the size of hydrothermal carbon microspheres (HCM) with an ultra-high specific surface area of 3126 m²⋅g⁻¹ and a hierarchical pore structure from micropores to mesopores. X-ray diffraction pattern and Raman spectrum indicated that the PCM were amorphous and locally graphitized. The adsorption test for methylene blue demonstrated that the PCM had a monolayer adsorption capacity of 1368 mg⋅g⁻¹. The adsorption equilibrium was achieved at 3 h and reached 81.6% of the equilibrium adsorption amount in the initial 0.5 h. The adsorption thermodynamics analysis demonstrated that the adsorption was a spontaneous physicochemical process. In addition, the adsorption performance of PCM displayed satisfactory pH stability.