One-pot solid-state synthesis of zirconia-activated carbon nanocomposites for excellent dye adsorption kinetics

The current work illustrates the solid-state route synthesis of Zirconium dioxide nanoparticles and Zirconium dioxide-activated carbon nanocomposites at low temperature (300 °C). Prepared samples are tested for Rhodamine B (RhB) absorption experiments at various adsorption conditions (e.g., pH, temperature) and discussed efficiency, the kinetics, isotherm models, and adsorption mechanism to determine the optimal adsorption conditions for the removal of RhB dye. The results show that the prepared samples efficiently absorb RdB and obtain removal efficiencies of 66 and 86% in 1 h, respectively. When the pseudo-first-order and pseudo-second-order adsorption kinetic models are used to test the adsorption data, the result fits the pseudo-first-order model better. The Freundlich and Langmuir adsorption isotherms are employed to model the isotherm data to get the maximum adsorption capacity (MAC). The MAC for Zirconium dioxide nanoparticles and Zirconium dioxide-activated carbon nanocomposites are found to be 5.1177 and 17.068 mg/g, respectively. The results clearly reveal that the Langmuir model captured the data better, demonstrating that monolayer adsorption dominated the absorption process. Additionally, prepared Zirconium dioxide-activated carbon nanocomposites are examined for reuse, and exhibit three cycles of recyclability.