Synthesis of mulberry wood waste biochar through acid modification for removal of dyes: experimental and DFT-based analysis

In this study, a new adsorbent, mulberry wood waste biochar modified with cinnamic acid (CA-MWB), is generated to capture the methylene blue dye (MB) from an aqueous solution. The synthesized material was characterized using a variety of physicochemical methods, such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD), and several parameters, including initial concentration, contact time, pH, and adsorbent dosage, were examined. Initial concentration (100 mg/L), adsorbent dose (0.15 g), pH 9, and contact duration 120 min were the settings that worked best. According to model fitting findings, the Temkin isotherm ( R 2 = 0.93813) and the pseudo-second-order kinetic model ( R 2 = 0.9978) both properly represent the adsorption process, showing that the adsorption mechanism was chemisorption and monolayer contact, respectively. The biochar treated with cinnamic acid has effective adsorption properties for removing methylene blue (95%). The electrostatic attraction was discovered to be the main factor in the hybrid system through density functional theory (DFT) analyses of the interfacial interaction between cinnamic acid and the surface of biochar. The adsorption mechanism was shown graphically by the molecule electrostatic potential interaction diagram. These results provide a fresh window for scholars to comprehend adsorption behavior.