Bamboo charcoal derived high-performance activated carbon via microwave irradiation and KOH activation: Application as hydrogen storage and super-capacitor

This paper attempts to prepare high-performance activated carbon (HP-AC) from bamboo charcoal (BC) as raw material using microwave irradiation as heating source and potassium hydroxide as activating agent. The influence of factors, such as activation time (3-15 min), KOH/C ratio (1:1-6:1) and particle size (0.147-2 mm) on its performance (the carbon yield and adsorptive capability) were investigated. The textural porosity and surface chemistry of HP-AC were determined by scanning electron microscope (SEM) analyzer, N 2 adsorption method and Fourier-transform infrared (FT-IR) spectrometer. The adsorptive properties of HP-AC were examined using iodine solution and methylene blue as model dye compound and hydrogen adsorbate. The effect of porosity and surface functionalities on the electrochemical capacitance of HP-AC were measured by cyclic voltammetry measurements. Under the best preparation conditions (activation time of 8 min, KOH/C ratio of 5:1 and particle size of 0.71-1.4 mm), the following results were obtained for the specific surface area, micro surface area, external surface area, total pore volume, iodine adsorption value, methylene blue adsorption value, carbon yield, hydrogen storage capacity and super capacitance value: 2,446 m 2 /g, 901 m 2 /g, 1,545 m 2 /g, 1.48 mL/g, 2,226 mg/g, 47.5 mL/0.1 g, 34.3%, 0.93 wt% (17.3 MPa, 25°C) and 3.63 wt% (1.0 MPa, -196°C), 212 F/g, respectively. The findings revealed the potential of BC as a raw material for the preparation of HP-AC, and to determine its potential applications of HP-AC as hydrogen storage and super-capacitor material.