Highly efficient and selectivity removal of heavy metal ions using single-layer NaKMnO nanosheet: A combination of experimental and theoretical study.

Manganese oxides (MnO) are widely applied in heavy metal ions removal due to their low-cost, environmental-friendly and biocompatibility. However, the adsorption capacity of MnO need to be further improved to satisfy the demand of practical application. Herein, a highly dispersed single layer NaKMnO nanosheet was synthesized by a facile wet-chemical method with sodium dodecyl sulfonate as surfactant. The high surface specific area, excellent dispersibility and abundant oxygen vacancies endowed NaKMnO nanosheets with potential in heavy metal ions adsorption. The adsorption experiments results showed that NaKMnO nanosheets possessed high efficiency and selectivity towards lead ion (Pb) with a high adsorption capacity of 2091.8 μmol g. The NaKMnO also showed an excellent reusability with the removal rate of 95.4% for Pb even after five cycles. Moreover, both the theoretical calculation and experimental data illustrated that the single layer NaKMnO nanosheets possess high selectivity to Pb adsorption.