Zinc oxide nanoparticles coated with benzimidazole based ionic liquid performing as an efficient CO2 capture: Experimental and Theoretical studies

Abstract

The CO2 content in the air has increased considerably in recent years, causing climate change by increasing the average global temperature. The present work deals with the capture of CO2 by ZnO NPs coated with benzimidazole-based ionic liquid (IL@ZnO), showing that it is capable of CO2 capturing efficiently (80%–90%) at room temperature. The performance of the sample in the CO2 adsorption was analyzed analytically. Thermal gravimetric analysis indicates the interaction of IL@ZnO (surface layer, < 0.5 nm) with CO2 and H2O. The amount of CO2 adsorbed by IL@ZnO (d = 670 nm) was measured by weight loss experiments, and also by infrared spectra (IR 2000∼1200 cm−1), where an increase of the peak intensity (1640 and 1430 cm−1) corresponding to CO2 was observed. With Density Functional Theory (DFT), the interaction between CO2 and IL, ZnO, or IL@ZnO was studied, showing that IL coating on ZnO plays a key factor in the adsorption to yield IL@ZnO/CO2 as a more stable adduct than the others, performing as an excellent CO2 capture.