Low-temperature CO2 adsorption on Titania nanotubes (TNTs)

In Carbon dioxide capture and storage (CCS) technology, adsorption of CO2 on solid adsorbents has been widely investigated as a means of an alternative to benchmark absorption technology, which is having many formidable problems. The various classes of solid adsorbents that have been investigated for CO2 capture include zeolites, carbon based adsorbents, metal organic frameworks (MOFs), metal oxides, and alkaline ceramics. Among several types of metal oxide based adsorbents for CO2 capture, titanium-based materials exhibit exciting prospects for CO2 adsorption owing to high specific surface area and ion-exchangeability. The present work investigates the CO2 adsorption on Titania nanotubes (TNTs) at low-temperature. To this end, nano TiO2, synthesized using TiCl4 by acid-hydrolysis method is used as a starting material for the synthesis of TNTs via hydrothermal treatment. Both nano TiO2 and TNTs are characterized using different techniques and subsequently investigated for CO2 adsorption. TNTs exhibited better saturation adsorption capacity (0.35 mmol g−1) compared with nano TiO2 (0.17 mmol g−1) at 30°C, 1 bar. The adsorption kinetics of CO2 on both the adsorbents obeys the pseudo-second-order kinetics well.