Rapid preparation strategy of highly microporous activated carbons for gas adsorption, via tunable-energy-density microwave heating

Microwave heating for the production of activated carbons has garnered significant research interest in the realms of gas adsorption. Nonetheless, the effect of tunable-energy-density microwave irradiation on the production of activated carbons is unclear. Herein, we report a tunable-energy-density microwave heating strategy to rapidly prepare highly microporous activated carbons. With the raising microwave energy density, the pore volume increases from 0.68 cm³ g⁻¹ to 0.89 cm³ g⁻¹, with a 70% decrease in the preparation time. Moreover, due to the high ratio of micropore (84.4%–86.6%) and great hydrophobicity, the optimal toluene adsorption capacity reaches 0.56 g g⁻¹ and 0.47 g g⁻¹ in the dry and wet (97% RH) environment, respectively. Due to the high ratio of ultramicropore (62.6%–69.0%), at 1 bar, the optimal CO₂ uptake for 25 °C and 0 °C reaches 4.27 mmol g⁻¹ and 6.41 mmol g⁻¹, respectively. This study introduces a straightforward and effective method for the swift production of activated carbons, applicable across a spectrum of uses.