Preparation and CO2 adsorption properties of porous carbon from camphor leaves by hydrothermal carbonization and sequential potassium hydroxide activation

Abstract

In this work, porous carbon was prepared from camphor leaves (CLs) by hydrothermal carbonization (HTC) and sequential potassium hydroxide activation. The morphology, porous structure, chemical properties, and CO₂ capture capacity of the produced materials were investigated. The influence of HTC temperature on the material structure and capture capacity was studied. HTC temperature was found to have a major effect on the structure of the products and their CO₂ capture capacity. The porous carbon obtained under HTC temperature of 240 °C exhibits a high ratio of microporosity, a large specific surface area (up to 1633.71 m² g⁻¹) and a maximum CO₂ adsorption capacity of 6.63 mmol g⁻¹ at 25 °C under 0.4 MPa. The Langmuir isotherm model depicts the equilibrium data much better than the Freundlich isotherm model. The pseudo-first-order kinetic model describes the kinetic data better than the pseudo-second-order kinetic model. Our results demonstrate that the porous adsorbents prepared from CLs provide a feasible option for CO₂ capture with low cost, environmental friendship and high capture capability.