Construction of oxygenated porous biochar by dual activation method for highly efficient removal of tetracycline from aqueous solution

The excessive use of tetracycline (TC) poses a significant threat to both the environment and human health. Therefore, there is an urgent need to develop tetracycline removal materials that are cost-effective, efficient, and easy to prepare in order to promote the development of society. In this study, we successfully prepared oxygen-enriched porous biochar (OPBC) from biomass starch through dual activation with bimetallic salt and hydrogen peroxide. The preparation process is streamlined by this method, resulting in a product with exceptional structural attributes: a large surface area of 1790 m 2 /g, an abundant pore structure, and a high oxygen content of 26 %. It has been demonstrated through experiments that OPBC possesses a remarkable adsorption capacity for TC in aqueous solutions, with a maximum capacity of 1357.9 mg/g. Theoretical calculations, corroborated by experimental data, indicate that the superior adsorption efficiency is predominantly attributed to the interaction between surface oxygen groups and TC molecules, enhanced by the elevated oxygen content on the surface. Furthermore, the results imply that hydrogen bonding, electrostatic interactions, π-π stacking, and the pore structure collectively contribute to the adsorption mechanism. This study not only presents a new, cost-effective, and efficient method for treating TC-contaminated water, but also offers a new perspective on the high-value utilization of agricultural by-products for environmental protection.