Enhanced Phosphate Adsorption by Cerium-Doped Porous Boron Nitride Nanosheets

Porous boron nitride material (p-BN), as a nanomaterial, is often used in pollutant removal (antibiotics and heavy metal ions in water, etc.), but its effectiveness for the removal of anionic pollutants has rarely been reported. Here, a cerium oxide modified p-BN (Ce/p-BN-X) was prepared and used for phosphate removal. It has a high specific surface area, a rich pore structure, abundant reactive groups such as amino groups, positively charged oxygen vacancies, and high stability, which enhanced the adsorption of phosphate. Moreover, the adsorption kinetics and isotherms analysis revealed that the adsorption capacity of Ce/p-BN-4 was 22.05 times higher than that of p-BN at an initial concentration of 20 mg L–1. The adsorption mechanism mainly includes ion exchange, inner-sphere complexation, and electrostatic attraction. In summary, this work provides a simple strategy to improve the adsorption of p-BN on phosphate, which greatly compensates for the deficiency of p-BN in anion adsorption and has great potential for application.