Advanced multiphase nanocomposites for effective malachite green dye removal.

In this study, novel nanocomposites composed of Pb(2)(CrO(4))O, MgO, MgCrO(4), and carbon (MP600 and MP800) were synthesized via the Pechini sol-gel method at 600 and 800 (o)C, respectively. The materials were characterized using XRD, FTIR, HR-TEM, FE-SEM, BET, and EDX techniques. XRD analysis revealed average crystallite sizes of 62.4 nm for MP600 and 73.6 nm for MP800. HR-TEM images showed that MP600 consisted of smaller, more uniform spherical particles, while MP800 exhibited larger and slightly aggregated structures. The nanocomposites were applied for malachite green dye removal from aqueous media under optimized conditions of pH 10, contact time of 50 min for MP600 and 70 min for MP800, and temperature of 298 K. MP600 exhibited a higher adsorption capacity (425.53 mg/g) than MP800 (362.32 mg/g). The adsorption followed the pseudo-second-order kinetic model and fitted the Langmuir isotherm well. Thermodynamic results indicated that the process was spontaneous and exothermic. MP600 also showed excellent regeneration efficiency over multiple cycles, highlighting its potential as a promising, cost-effective adsorbent.