Engineering hydrophobic carbon sponge from metal−organic complexes@melamine foam composite for advanced volatile organic compounds adsorption

In this work, highly hydrophobic carbon sponges with large specific surface area were successfully prepared (denoted as HHCS-1, HHCS-2 and HHCS-3). By simply increasing temperature and decreasing heating rate, the carbon sponge showed unique sphere structures at the points of each connection. Moreover, the unique sphere structure changes from no obvious fold to obvious fold. HHCS-3 with the largest surface area of 2926.2 m² g⁻¹ exhibited superior adsorption performance for methanol, acetone and toluene, and the largest saturated adsorption capacity reached as high as 172, 365 and 429 mg g⁻¹. The ultralow water vapor absorption rate indicates that HHCSs have excellent hydrophobicity and water vapor uptakes are only 7.62%, 6.71% and 6.25% at the relative humidity of 50%. When water vapor was introduced into toluene gas (RH = 50%), the toluene-saturated adsorption capacities are only reduced by 7.2−8.6% compared with under dry conditions. The adsorption capacity of toluene on the HHCSs is higher than that of methanol and acetone. Kinetic adsorption models show that the adsorption of methanol, acetone and toluene onto HHCSs mainly depends on surface adsorption.