Porous boron nitride nanoribbons with large width as superior adsorbents for rapid removal of cadmium and copper ions from water

Novel porous boron nitride nanoribbons (BNNRs) were successfully developed as superior adsorbents to rapidly remove cadmium and copper ions from water. The resultant BNNRs possessed large specific surface areas and small average porosity (866 m2 g−1 and 2.1 nm, respectively). The width of a single nanoribbon was approximately 660 nm. The maximum adsorption capacities for Cd2+ and Cu2+ ions were about 530 mg g−1 (C0 = 600 mg L−1, pH 6, dosage = 1 g L−1) and 331 mg g−1 (C0 = 500 mg L−1, pH 5, dosage = 1 g L−1), respectively. Further, BNNRs possessed the ability to rapidly adsorb Cd2+ and Cu2+ within 10 min and 20 min, respectively. Interference and reuse experiments demonstrated that BNNRs exhibited superior adsorption performance with easy recyclability and sustainability, indicating that the adsorbents might be applied to purify heavy metal ions from diversified water including wastewater and drinking water at pH 3–8 or under the interference of other metal ions. The XPS and FTIR analyses revealed that the possible mechanism of adsorption is the chelation and attraction of heavy chemical metals by surficial chemical bonds, such as B–O and –NH2 bonds. With regard to the cadmium (1 mg L−1) and copper (10 mg L−1) contents of simulated real water, the WHO standard can be reached within 10 min and 1 min for BNNRs (dosage = 1 g L−1), respectively. Therefore, the as-prepared BNNRs are ideal candidates for water purification applications.