Titanium dioxide modified with various amines used as sorbents of carbon dioxide

Abstract

In this study, titanium dioxide was modified with various amines through hydrothermal treatment for adsorption of CO₂. The carbon dioxide adsorption performance of the prepared samples was measured using an STA 449 C thermobalance (Netzsch Company, Germany). The morphological structures, functional groups and elemental compositions of the unmodified and amine-modified titanium dioxide sorbents were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR/DR) and scanning electron microscopy (SEM), respectively. The results showed that modification of TiO₂ with amines through hydrothermal treatment is a simple method to prepare CO₂ sorbents with high adsorption capacities. Moreover, the results revealed that TEPA-modified titanium dioxide shoved the highest adsorption capacity, enabling an increase in CO₂ uptake from 0.45 mmol CO₂ g⁻¹ in the case of raw TiO₂ to 1.63 mmol CO₂ g⁻¹. This result could be indirectly related to the fact that TEPA has the highest amino group content among the three amines used in our research. Additionally, durability tests performed by cyclic adsorption–desorption revealed that TEPA modified titanium dioxide also possesses excellent stability, despite a slight decrease in adsorption capacity over time.