Calcined products of Mg-Al layered double hydroxides/single-walled carbon nanotubes nanocomposites for expeditious removal of phenol and 4-chlorophenol from aqueous solutions

We reported a facile method for preparing calcined products of layered double hydroxides/single-walled carbon nanotubes (CLDH/SWCNT) nanocomposites. A large number of pore channels with diameters between 30 and 150 nm were formed in CLDH/SWCNT nanocomposites. This led to a significant increase in specific surface area and pore volume of nanocomposites. Experimental data showed that the removal rates of phenol and 4-chlorophenol by CLDH/SWCNT can reach 91.7% and 99.5%, respectively. By fitting the Langmuir adsorption isotherm, the maximum adsorption capacities of CLDH/SWCNT for phenol and 4-chlorophenol adsorption under optimal conditions (pH 6, adsorbent dosage of 3.5 g/L, contact time of 24 h, and temperature of 303 K) were 219.0 and 255.6 mg/g, respectively. Remarkably, after 10 cycles of recycling, the material can still effectively adsorb target pollutants. Compared to most existing adsorbents, CLDH/SWCNT nanocomposites have the advantages of high maximum adsorption capacity, wide range of effective pH for adsorption, fast adsorption speed and excellent recyclability. Due to their superior adsorption performance, CLDH/SWCNT may become an excellent adsorbent with high potential for treating phenolic pollutants.