Hybrid amino-functionalized TiO2/sodium lignosulfonate surface molecularly imprinted polymer for effective scavenging of methylene blue from wastewater

Abstract

A novel amino-functionalized titanium dioxide (TiO2) surface molecularly imprinted polymer (ATMIP) with high adsorption selectivity and quick adsorption of methylene blue (MB) was successfully prepared by using sodium lignosulfonate (SL) as a functional monomer. The BET analysis indicated that ATMIP possessed a mesopore structure with a high specific surface area of 56.3266 m2/g and a good visible light absorption property with a bandgap of 2.90 eV. The efficiency of adsorption, adsorption selectivity, and photodegradation ability of MB in wastewater by the ATMIP and non-molecularly imprinted polymer (ATNIP) were comparatively investigated. The results indicated that ATMIP can reach quick adsorption equilibrium in short time (10 min). The adsorption kinetics and adsorption isotherms are well fitted by the pseudo-second-order and the Freundlich isotherm model, respectively. ATMIP exhibits excellent adsorption capability and selectivity toward MB in binary systems of MB/CV or MB/RB. The photodegradation efficiency of ATMIP can reach 93.9% in 2 h. In addition, the adsorption efficiency and degradation efficiency of MB are 66.79% and 77.98% by regenerated ATMIP after 4 cycles, respectively. It was concluded that ATMIP may potentially serve as a good candidate for high adsorption selectivity and quick removal of MB from the mixed dyes wastewater.