Enzymatic hydrolysis lignin functionalized Ti3C2Tx nanosheets for effective removal of MB and Cu2+ ions

Functionalized two-dimensional Ti 3 C 2 T x (TN-EHL) was prepared as an effective adsorbent for removal of methylene blue dye (MB) and copper ions (Cu 2+ ). Enzymatic hydrolysis lignin (EHL), a reproducible natural resource, was used to functionalize the Ti 3 C 2 T x nanosheets. EHL can not only introduce active functional groups into TN-EHL but also prevent the oxidation of Ti 3 C 2 T x , thus promoting the adsorption performance of TN-EHL. The maximum adsorption capacities of TN-EHL50 (in which the EHL content is 50 wt%) for MB and Cu 2+ were 293.7 mg g −1 and 49.96 mg g −1 , respectively. The higher correlation coefficients ( R 2 ) of MB (0.9996) and Cu 2+ (0.9995) indicating that their adsorption processes can be described by the pseudo-second-order kinetic model. The MB adsorption data fit the Freundlich isotherm with R 2 of 0.9953, whereas the Cu 2+ ions adsorption data fit the Langmuir isotherm with R 2 of 0.9998. The thermodynamic analysis indicates that the adsorption process of MB and Cu 2+ on TN-EHL50 is spontaneous and endothermic. Significantly, the Cu 2+ ions were reduced to Cu 2 O and CuO particles during the adsorption process. Therefore, TN-EHL has a great potential as an environmentally friendly adsorbent for MB removal and recovery of Cu 2+ ions from wastewater.