Development of a Manganese Dioxide-Decorated Activated Carbon Nano-sorbent via Co-precipitation method for efficient lithium ion adsorption from aqueous solutions

Abstract

ABSTRACT Recently, the utilization of lithium has increased significantly, particularly in high-tech industries such as nuclear, aerospace, automotive, battery, military, glass and ceramic, and lubricants. However, lithium recovery methods from brines present certain drawbacks, making lithium exploitation a global challenge. A comparative analysis of lithium recovery methods from brine solutions indicates that the adsorption method holds promising potential for separating lithium from low-concentration solutions. Despite this, the quest for an effective and efficient adsorbent for lithium-ion adsorption remains a challenge, necessitating the development of an adsorbent, using readily available materials. In this study, carbon-active underwent chemical modification. Notably, the co-precipitation method was employed for the first time to create a composite adsorbent decorated with manganese dioxide (MnO2). Various analyses, including XRD, SEM-EDS, FTIR, and BET, were conducted to elucidate the structural, morphological, physical, and chemical properties of the adsorbent. This synthesized adsorbent was applied to the adsorption of lithium from an aqueous sample. Exploration of adsorption parameters affecting capacity led to the identification of optimal conditions: 14-hour duration, an adsorbent dosage of 0.02 g, and an ambient temperature of 25°C, in a lithium solution with a concentration of 60.4 ppm. Under these conditions, the maximum adsorption capacity of the adsorbent was determined to be 30.5 mg/g. Based on experimental results, kinetic and adsorption isotherm models were investigated. The Pseudo-quadratic kinetic model, with an R2 value of 0.999, emerged as the most suitable for describing the adsorbent’s behavior. The Hill isotherm model with R2 = 0.9634 is the most appropriate isotherm model to describe the adsorbent behavior. Additionally, the selectivity of the adsorbent in the presence of other ions was investigated. The adsorbent’s reusability was examined, and after two recycling periods, the adsorbent maintained an efficiency of up to 88%, demonstrating its stability. The CAC-MnO2-P composite adsorbent shows technical and economic promise for industrial use in lithium-ion recovery processes.