Ordered mesoporous carbons originated from non-edible polyethylene glycol 400 (PEG-400) for chloramphenicol antibiotic recovery from liquid phase

• PEG-400 is a viable carbon source for ordered mesoporous carbon synthesis.
• ABA-16 ordered mesoporous carbon is a good adsorbent for chloramphenicol.
• Three-parameter adsorption isotherms produced the smallest non-linear errors.
• CPC/ABA-16 adsorption system is spontaneous and endothermic in nature.

Ordered mesoporous carbon (OMC) coded as ABA-16 has been successfully synthesized through hard-templating method using hexagonal mesoporous silica (HMS) as a template and non-edible polyethylene glycol 400 (PEG-400) as a liquid carbon source. The surface area of ABA-16 was measured at 1026 m2 g−1 with the total pore volume of 0.99 cm3 g−1 and the average pore diameter of 3.89 nm. The presence of ordered hexagonal structure in HMS and OMC was visualized through transmission electron microscopy (TEM). A series of batch adsorption studies was conducted on chloramphenicol (CPC) at different initial concentrations ranging from 50 to 400 mg L−1 at 303–323 K. The effect of pH on CPC adsorption was studied within the pH of 3–11. The maximum CPC monolayer adsorption capacity, Qm was 210 mg g−1 at 303 K. For all tested conditions, three-parameter adsorption isotherm models produced better fittings than the other two-parameter models. Pseudo-second order kinetic model gave a better fit to the experimental data compared to the other models. Thermodynamic studies suggested that CPC adsorption on ABA-16 was spontaneous and endothermic in nature. From the FTIR studies, it can be hypothesized that the two possible adsorption mechanisms; n–π interactions of carboxylic functional group on the carbon surface and the aromatics (benzene ring) of CPC, and π–π interactions of benzene rings in CPC with aromatics rings on the surface of the carbon. This work has clearly demonstrated that PEG-400 was a viable alternative for conventional edible/hazardous carbon sources used for nanocasting of OMCs.