Removal of Nicotine From Environmental Tobacco Smoke Using Tannic Acid Modified Activated Carbon

ABSTRACT A tannic acid‐modified activated carbon (TA‐AC) with enhanced nicotine adsorption performance was developed via a simple and low‐cost surface modification method. SEM, BET, and XRD analyses confirmed that TA‐AC retained well‐preserved porous structures (specific surface area of 974 m 2 /g, average pore diameter of 1.91 nm). TA molecules aggregated in the pores and cracks of TA‐AC. FTIR, XPS, Hammett indicator method and thermogravimetric analysis confirmed surface acidity and the presence of TA (1.8 wt%). The liquid‐phase adsorption experiment showed that the TA‐AC adsorption capacity for nicotine reached 19.74 mg/g, higher than that of AC (11.51 mg/g). A static gas‐phase adsorption test was carried out to simulate TA‐AC's adsorption of nicotine from second‐hand smoke. 92.17% of nicotine was removed within 1 h, and the nicotine removal efficiency remained 80% after 5 adsorption‐desorption cycles. The computational analysis with DFT simulation revealed lower binding energy between TA and nicotine than most oxygen‐containing functional groups on activated carbon. FTIR results provided evidence for the adsorption of nicotine by TA‐AC. Eight types of commercial AC modified by industrial‐grade TA exhibited high nicotine removal efficiencies (78%‐95%) from second‐hand smoke. Therefore, both TA‐AC and this modification method have potential applications in the field of environmental protection.