Preparation of micro-mesoporous functionalized zeolites by nanosecond pulsed discharge-amino co-modification for efficient Ni(II) ions removal

Abstract

The severe adverse impacts of toxic metal ions on ecosystems and human health call for the urgent development of an efficient adsorbent. In this study, a novel micro-mesoporous zeolite material was prepared by nanosecond pulsed discharge-amino co-modification method to selectively adsorb Ni(II) ions. The prepared micro-mesoporous adsorbent exhibited a large specific surface area (1042 m2 g−1) and were rich in -NH2 and -COOH that can produce surface complexation and electrostatic adsorption with Ni(II) ions. The optimal experimental parameters were obtained at 8 min of discharge time, 16 kV of pulse peak voltage, 1 kHz of pulse repetition frequency, and pH = 7. The Ni(II) ions removal efficiency of nanosecond pulsed discharge-amino co-modified MCM-41 reached 98% within 20 min, an increase of 54% and 26% compared to the raw and solo amino modification, respectively. The adsorption processes of Ni(II) ions were well fitted by pseudo-second-order and Langmuir isotherm models, indicating that the adsorption involves monolayer chemisorption. Despite the presence of other coexisting ions, the prepared zeolites retained their excellent adsorption selectivity for Ni(II) ions. This co-modification method overcomes the drawback of mesopores blockage and further implants micropores in adsorbents, providing a novel idea and broad prospect for adsorbent modification and removal of Ni(II) ions.