Adsorption of Azo Dye Onto TiO2 Nanoparticles Prepared by a Novel Green Method: Isotherm and Thermodynamic Study

Abstract

     The current study examined the use of Sansevieria plant leaves extract as an environmentally acceptable, inexpensive, and safe green approach for creating titanium dioxide nanoparticles (NPs). Batch studies have been used to test the particles' capacity to bind to the azo dye congo red (CR), which has been adsorbed from its aqueous solution. The effects of many factors, including the weight of TiO2 NPs, the contact duration to reach equilibrium, the concentration of CR, temperature, and pH, have been investigated. Both the Freundlich and Langmuir models were used to analyze experimental results. According to the high values of the Freundlich model's correlation coefficient R², it is discovered that the adsorption of CR dye onto nano TiO₂ is well-suited. The kinetics analysis for the adsorption trials proposed the pseudo-second-order. Thermodynamic data showed that the CR dye adsorption onto nano TiO₂ is a physical process that happens spontaneously and endothermically with increasing unpredictability.