D‐Fructose‐Assisted Sol–Gel Synthesis of ZnFe ₂ O ₄ Nanoparticles for Efficient Sequestration of Cr (VI)

ABSTRACT In this study, we report the fabrication of ZnFe 2 O 4 nanoparticles (ZF) through the sol–gel technique using D‐fructose as a complexing agent, followed by calcination at 600°C for the first time. The prepared sample was characterized by XRD and FTIR, which confirmed the formation of pure ZF phase. The SEM investigation revealed the formation of rough surfaces with voids, probably due to the formation of distinct ZF nanoparticles with irregular morphology and a wide range of sizes ranging from 50 to 1200 nm. Such features were obtained by synthesizing the precursors under controlled hydrolysis of Zn 2+ and Fe 3+ in the presence of D‐fructose at a lower alkaline pH, as well as uncontrolled precipitation at higher pH (9.5). The maximum uptake efficiency for Cr (VI) was found to be 95% at 3.5 pH, 10 mgL −1 of Cr (VI), and 1 gL −1 of ZF. Kinetic studies revealed that Cr (VI) sorption followed an electrostatic attraction mechanism, as the experimental data were fitted to a pseudo‐second‐order equation. Additionally, the Cr (VI) uptake was suggested as homogeneous and monolayer for fitting the Langmuir equation. Maximum Langmuir uptake capacity was determined as 66.813 mg g −1 , indicating the high potential of ZF toward Cr (VI) capture.