NiO/AC Active Electrode for the Electrosorption of Rhodamine B: Structural Characterizations and Kinetic Study

Abstract

In this work, the aim was to enhance the performance of activated carbon (AC) as an electroadsorbent by incorporating NiO particles, thereby increasing its electrochemical capacity and its ability to adsorb Rhodamine B (RhB) dye. The prepared NiO/AC material was characterized using X-ray diffraction, scanning electron microscopy, BET surface area analysis, and infrared spectroscopy. The study involved the preparation of AC from almond shell biomass and the subsequent formation of a composite structure with NiO. The objective was to investigate the electrochemical adsorption capacity of the NiO/AC composite for RhB dye removal from simulated wastewaters. The experimental results demonstrated that the removal efficiency of RhB dye increased with an increase in the applied cell voltage. At a voltage of 1.4 V, a remarkable 100% removal efficiency was achieved. The electroadsorption process was well described by fitting the experimental data to the Freundlich isotherm model. The maximum adsorption capacities for RhB dye at concentrations of 7, 8, and 9 ppm were determined to be 149, 150, and 168 mg/g, respectively. Based on the obtained results, an electroadsorption mechanism was proposed to explain the observed behavior of the NiO/AC composite in adsorbing RhB dye. Overall, this study highlights the potential of the NiO/AC composite as an effective electroadsorbent for the removal of Rhodamine B dye from wastewater. The improved electrochemical capacity, coupled with the high adsorption capacity of the composite, makes it a promising material for wastewater treatment applications.