چكيده به لاتين
In this study, zinc ferrite (ZF) and and zinc ferrite/reduced graphene oxide functionalized with amine (ZF/rGO-MEA) nanocomposites were investigated for CO₂ adsorption and sensing. Structural analyses using XRD, FTIR, BET, and FESEM techniques revealed that the nanocomposites possess suitable structures and high specific surface areas for CO₂ adsorption. Specifically, the adsorption capacity of the ZF/rGO-MEA30 nanocomposite was 3.9 mmol/g under 1 bar and 25°C, showing a significant improvement compared to pure ZF (2.2 mmol/g). To optimize the adsorption conditions, response surface methodology (RSM) with Central Composite Design was used, and the results showed that temperature, pressure, and loading of amine-functionalized reduced graphene oxide significantly affected the adsorption capacity. Under optimal conditions (25°C, 9 bar pressure, and 31.758% wt. loading of reduced graphene oxide), the adsorption capacity increased to 15.788 mmol/g. The Freundlich isotherm model best fit the experimental adsorption data, indicating that CO₂ adsorption on the nanocomposite is physical, multilayered, and occurs on a heterogeneous surface. Kinetic results also showed that the fractional-order kinetic model best matched the data, suggesting that the adsorption process is influenced by complex reactions with multiple pathways. Thermodynamic analysis confirmed that the adsorption process is exothermic and spontaneous. In the selectivity section, the ZF/rGO-MEA30 nanocomposite demonstrated a CO₂/N₂ selectivity of 24 at 25°C and a gas mixture ratio of 15:85, significantly higher than pure zinc ferrite with a selectivity of 16. In cyclic regeneration analysis, the ZF/rGO-MEA30 nanocomposite retained about 95.15% of its initial adsorption capacity after 5 adsorption-desorption cycles, indicating high stability and reproducibility under various operational conditions. In the sensing section, sensors based on the ZF/rGO-MEA30 nanocomposite performed better in CO₂ detection compared to ZF sensors. The ZF/rGO-MEA30 sensor exhibited a shorter response time (12 seconds) and faster recovery time (57 seconds) compared to the ZF sensor (response time of 15 seconds and recovery time of 81 seconds). Additionally, the sensitivity of the ZF/rGO-MEA30 sensor was 6.42079 per percent CO₂ concentration, almost double that of the ZF sensor (2.94887). A 30-day stability assessment of the sensors showed a response decrease of less than 7.09% for the ZF/rGO-MEA30 sensor, indicating stable and reliable performance over the long term. This study demonstrated that the ZF/rGO-MEA30 nanocomposite, due to its optimized structural and functional properties, is recognized as an efficient adsorbent and sensor for CO₂, with high potential for industrial and environmental applications.
