Climate change is becoming one of the most severe problems ever faced by mankind. The change in global climate, caused due to extreme levels of carbon dioxide (CO2), has led to sudden weather patterns in the form of droughts and floods, which are not only disruptive but are also detrimental to life.
An important way of reducing any escalations in climate severity is by reducing atmospheric levels of CO2. Researchers at the Tata Institute of Fundamental Research (TIFR) have created an innovative CO2 sorbent which displays an excellent CO2 capture capacity and also a greater stability than that of traditional materials. When functional amines are immobilized on a porous solid support, it leads to efficient and stable CO2 sorbent materials as opposed to analogous liquid sorbents. However, a major disadvantage of this approach is that there is a significant decrease in the textural characteristics, such as pore volume and surface area, of these supports, resulting in reduced CO2 capture capacity.
In order to address this problem, TIFR scientists have developed new functionalized nanomaterials, which enable higher loading of amines with a minimum reduction in surface area.
Our fibrous nanosilica (KCC-1) should be a good candidate for use as a support to design efficient CO2 sorbents that would allow better capture capacity, kinetics and recylability.
Dr Vivek Polshettiwar - Lead Scientist, TIFR
A high surface area is a special aspect of KCC-1. Unlike in other popular materials, such as MCM-41 or SBA-15, this high surface area is not the result of deep mesoporous channels but is instead the result of a fibrous morphology, .
Sorbents based on KCC-1 exhibited a number of benefits when compared to traditional sorbents based on silica. These benefits include a minimum reduction in surface area following functionalization, a high loading of amines, and more accessibility of the amine sites to improve the efficiency of CO2 capture, i.e. kinetics, capture capability, and recyclability, thanks to the high accessible surface area and fibrous structure of KCC-1.
There is an increasing demand for these efficient sorbents, given the fact that CO2 capture provides an optimum solution to reduce rising CO2 levels. Solid sorbents not only have better efficiency, but they also provide a greater ability of addressing the limitations of liquid sorbents.
The application of mesoporous silica materials functionalized with different amino groups has been well documented. For instance, materials like MCM-41 and SBA-15 have attracted a great deal of attention, as they have huge pore sizes which can house a range of amine molecules. They also have high surface area that enables a better loading of these functional molecules. However, such materials tend to have reduced textural properties, KCC-1 addresses this issue.
The results of this research have been reported in the Journal Materials Chemistry A.