A facile synthesis of bimetallic Ni/Co-BTC hollow MOFs for effective removal of congo red

In this work, we employ an eco-friendly and highly efficient method for the successful removal of anionic azo dye (CR) using emerging Ni/Co-BTC hollow Metal-Organic Frameworks (MOFs). The MOFs was developed via a solvothermal synthesis method. Various kinetic models, adsorption capacities, isotherms (Langmuir and Freundlich), and thermodynamic stability assessments were used to predict the adsorption mechanism and the types of interactions present between CR dyes and Hollow MOFs. Our findings suggest that the adsorption process follows Freundlich isotherm, with PSO kinetic models indicating chemisorption and a maximum Langmuir adsorption capacity of 168.03 mgg−1. We observed a removal efficiency of 74% in neutral medium and 85% in acidic medium. Thermodynamic studies reveal the spontaneity of the process with endothermic enthalpy, attributed to the hydrogen bonding and electrostatic interactions between the dye molecule and the adsorbent. Furthermore, to investigate practical applicability, we conducted studies in real water and dye mixtures. All studies demonstrated that the prepared Ni/Co-BTC hollow MOFs show promising potential adsorbents for the CR dye removal from the wastewater, owing to their high efficiency and reusability.