Biomass-derived mesoporous and super-hydrophilic carbon manufactured by cycling-pressure-switching air activation process towards ultrahigh adsorption efficiency of tetracycline

Mesoporous and super-hydrophilic carbon materials have been synthesized with sugar cane bagasse via a cycling pressure-switching (CPS) air oxidation process. Facilitated by the pressure-switching process, reactive gas (air) can diffuse into porous channels for activation reaction and create rich mesoporous structure as well as abundant surface functional groups. Compared to conventional atmospheric pressure (AP) method, CPS process simultaneously maximizes the mesopore volume fraction (37%) and enriches the surface functional groups. Such unique carbon materials were systematically characterized by various techniques to reveal the evolution of pore structure and surface property. These materials have been demonstrated very effective for the adsorption of bulk antibiotics such as tetracycline (TC) and the maximum adsorption capacity of 671.14 mg/g was achieved at room temperature with feeding TC concentration of 150–400 mg/L⁻¹. In a word, this work presents an environmental benign approach to manufacture porous carbon with direct air activation, the unique features of the materials with large mesopore volume and superhydrophilic surface enable efficient adsorption of bulk molecules in aqueous solution and show promising application in antibiotics removal from polluted water.