Porous Carbon Derived from Wasted Cigarette Filters for Water Desalination Based on Capacitive Deionization

Porous carbon derived from wasted cigarette filters (WCFs) were synthesized using an atmospheric-pressure chemical vapor deposition, using KOH as an activator at 500—700 ℃. Brunauer-Emmett-Teller test showed that the surface area of porous carbon derived from WCFs increased with activation temperature. Micro- and meso-porous carbon (MMC) derived from WCFs at 700 ℃ (MMC700) exhibited a micro-pore dominant structure (pore size < 2 nm), with a surface area of 928 m²/g. MMC700 powder was made into electrodes for capacitive deionization and, with an initial NaCl concentration of 5 mmol/L, and the MMC700 electrode showed an ion adsorption capacity of 8.66 mg/g upon a bias of 1.2 V. MMC700 showed a carbon yield of 4.9% from its original WCFs. XPS showed that MMC700 contained a carbon content of 92.87%. 700 ℃ is a relative low activation temperature which provides a low vapor pressure of KOH, benefiting the environment. This work suggests a facile method of converting WCFs into porous carbon, and its application in water desalination based on capacitive deionization.