Zero-valent iron supported-lemon derived biochar for ultra-fast adsorption of methylene blue

Abstract Green-based materials represent a new promising class of ecofriendly and economic adsorbents. Herein, nano zero-valent iron supported-lemon derived biochar (NZVI-LBC) was prepared for the first time and examined in the adsorptive removal of methylene blue as a model pollutant. Different characterization tools were used to ensure the successful fabrication of the NZVI-LBC composite including FTIR, XRD, TEM, XPS, VSM, BET, and zeta potential analysis. It was found that the fabricated NZVI–supported biochar composite attained the propitious adsorbent criteria since it provided a supreme efficient adsorption process at short time. The reckoned maximum adsorption capacity of MB onto NZVI-LBC reached 1959.94 mg/g within merely 5 min. The obtained data clarified that the adsorption process of MB onto NZVI-LBC fitted pseudo 2 nd order kinetic model and Freundlich isotherm model. Besides, the adsorption process of MB onto NZVI-LBC was found to be endothermic in nature. In addition, NZVI-LBC composite revealed an excellent adsorption behavior even after seven cycles. The concrete results reflect the potentiality of NZVI-LBC composite to be a superb candidate to remove cationic pollutants from their aqueous solutions. Graphical abstract