Two-dimension N-doped nanoporous carbon from KCl thermal exfoliation of Zn-ZIF-L: E ffi cient adsorption for tetracycline and optimizing of response surface model

N-doped nanoporous carbon (NC) with two-dimensional structure derived from Zn-ZIF-L via KCl exfoliation and carbonization at different temperature were prepared for adsorptive removal of tetracycline (TC). Characterizations revealed the effective dopant of N atoms and low degree of graphitization with more defects related to the enhanced adsorption capacity of the NC materials. Benefiting from the huge surface area (2195.57 m(2) g(-1)), high porosity (1.34 cm(3) g(-1)) and accessible sheeting structure, the NC-800 exhibited its fast and efficient adsorption of TC in 60 min. Meantime, the maximum adsorption of TC could reach 347.06 mg g(-1). Effects of pH, humic acid (HA) and ionic strength (Na+, Ca2+) were studied along with the interactions among influencing factors investigated by response surface model (RSM). By optimizing experimental conditions from RSM, the adsorption capacity could increase to 427.41 mg g(-1). Additionally, electrostatic interaction and hy-drogen bond interaction might play a dominating role in adsorption reaction. The NC-800 could maintain a high adsorption level after four cycles. Therefore, the NC-800 with great adsorptive property and reusability could be considered as an effective adsorbent with promising potential in applications for water treatment.

Automated summary

N-doped nanoporous carbon derived from Zn-ZIF-L via KCl exfoliation and carbonization exhibited effective N atom doping, low degree of graphitization, and high defects, resulting in enhanced adsorption capacity. The NC-800 showed fast and efficient adsorption of TC with a maximum adsorption capacity of 347.06 mg g(-1), and could maintain high adsorption levels after four cycles, making it a promising adsorbent for water treatment applications.