Remarkable disposal of Rhodamine 6G dye from aqueous media employing easily fabricated novel nanocomposites

Rhodamine 6G is a hazardous cationic dye whose persistence in water threatens aquatic ecosystems by reducing light penetration and disrupting normal biological activity. Human exposure is also undesirable because it may cause toxic effects involving the skin, eyes, respiratory tract, and internal organs. In this work, novel Ba 2 MgB 6 O 12 /Zn 3 B 2 O 6 /Mg 2 B 2 O 5 /BaB 2 O 4 /C nanocomposites denoted as ZBM500 and ZBM700 were facilely synthesized by the Pechini sol-gel route at 500 and 700 °C for remarkable Rhodamine 6G removal. XRD confirmed the polycrystalline multiphase nature of both samples with average crystallite sizes of 52.5 and 71.3 nm for ZBM500 and ZBM700, respectively. EDX verified the presence of B, C, O, Mg, Zn, and Ba, while FE-SEM and HR-TEM revealed rough flake-like and granular features for ZBM500 and denser lamellar and block-like domains for ZBM700 with average particle sizes of 28.7 and 60.1 nm, respectively. Optimum adsorption occurred at pH 10 using 0.1 g adsorbent at 298 K within 60 min for ZBM500 and 80 min for ZBM700. The maximum adsorption capacities of ZBM500 and ZBM700 reached 432.90 and 320.51 mg/g, respectively. Adsorption was spontaneous, exothermic, predominantly physical, and best interpreted by the pseudo-first-order kinetic equation as well as the Langmuir isotherm. Efficient desorption with 2 M HCl and strong five-cycle reusability confirmed the practical promise of both adsorbents.