The rapid rise in atmospheric CO2 levels necessitates the removal of greenhouse gases. Direct Air Capture (DAC), as a representative negative emission technology, is a method to capture CO2 directly from the atmosphere and reduce global CO2 concentrations. Nanomaterials, categorized as nano objects and nanostructured materials, will play an essential role in enhancing DAC efficiency and performance through the development of advanced adsorption materials. The high reaction surface areas and porosity of nanomaterials are the foundational variables contributing to high rates of CO2 capture. Given that, this review aims to provide a comprehensive investigation of the novel nanomaterials in DAC, particularly with respect to parameters including material capture capacity, stability, effect of humidity, and cost. This review found that while nanofibers offer effective CO2 uptake under low pressure, they offer poor structural stability – a shortcoming overcome by the diverse structural flexibility found in nanocomposite materials and their comparatively affordable fabrication costs. However, further research and commercial development are needed for these materials to increase the adsorption capacity and stability, as well as, importantly, reducing cost and energy consumption.
Link to the full paper here.