Adsorption of Pentachlorophenol from Aqueous Solution on Dodecylbenzenesulfonate Modified Nickel−Titanium Layered Double Hydroxide Nanocomposites

Dodecylbenzenesulfonate (DBS) modified Ni R Ti layered double hydroxides (LDHs) with different Ni/Ti molar ratios were prepared as hydrophobic organics sorbent by one-step co-precipitation method. The basal spacing of DBS−Ni R Ti ( d 003 = 2.99−3.54 nm) is significantly increased compared with cyanate-intecalated Ni 5 Ti−LDH (0.73 nm) due to the intercalation of surfactant anions between the LDH layers. The greatly enhanced contact angle (123.5−144.2°) for water and the reduced surface area (1.72−3.25 m 2 /g) of DBS−Ni R Ti nanocomposites demonstrate their strong hydrophobic property. The highest sorption capacity for pentachlorophenol (PCP) of DBS−Ni 5 Ti among all samples is intimately related to its stacking model of the interlayer hydrophobic moiety and organic carbon content. The linear model well-fits for PCP sorption isotherms on DBS−Ni R Ti ( R 2 > 0.96), implying a partitioning sorption process. Along with the effect of medium pH and temperature on PCP sorption−desorption study on DBS−Ni 5 Ti, an adsolubilization mechanism, an exothermic sorption nature, and a significant hysteresis phenomenon during sorption−desorption process are revealed.