One-Pot Synthesis of Boron Carbon Nitride Nanosheets for Facile and Efficient Heavy Metal Ions Removal

Mercury ions (Hg-2(+)) and lead ions (Pb-2(+)) are two of the most toxic heavy metal ions; thus, the efficient and effective removal of them is of great significance. Herein, a one-pot synthesis protocol has been proposed to synthesize boron carbon nitride nanosheets (BCN NSs) via the pyrolysis of the mixture of melamine and boric acid. To optimize the synthesis conditions, a series of products were made by varying the molar ratio and heating temperature. Finally, the BCN NSs obtained from the mixture of melamine and boric acid with the molar ratio of 3:3 at 550 degrees C was selected for the best Hg-2(+) and Pb2+ removal efficiency. Due to the successfully introduction of abundant function groups, enhanced specific surface area and hydrophilicity and electrostatic attraction ability, BCN NSs exhibit excellent adsorption perform ance toward Hg-2(+) and Pb-2(+) with the maximum adsorption capacity of 625.0 and 210.97 mg g(-1), respectively. The sorption isotherms fit well with the Langmuir adsorption model which suggest the monolayer adsorption behavior, and the pseudo second-order kinetic adsorption processes indicate the chemisorption mechanism. Besides, BCN NSs show excellent chemical stability, and the adsorption capacities remain more than 90% even after 6 adsorption/desorption cycles. By virtue of the cost-effective and facile production methodology, combined with the excellent absorption performance, the BCN NSs show great potential for practical application in the field of wastewater purification.