Waste and biomass-based nanomaterials for CO2 capture

The world’s countries emit vastly different amounts of heat-trapping gases (greenhouse gases) into the atmosphere. Human activities such as burning fossil fuels for electricity, heat, and transportation are responsible for the increase in greenhouse gases in the atmosphere over the last 150 years. CO2 emissions also result from some industrial and resource extraction processes and the burning of forests during land clearance. In 2020, the top carbon dioxide (CO2) emitters were China, the United States, the European Union, India, the Russian Federation, and Japan. These data include CO2 emissions from fossil fuel combustion, as well as cement manufacturing and gas flaring. Together, these sources represent a large proportion of total global CO2 emissions. The imbalance in atmospheric CO2 concentration caused by emissions from various anthropogenic sources has led to variations in climate across the globe. It has created an urgent demand for developing methods and materials to capture and store CO2 in a cost-effective and environment-friendly way. Many research groups have addressed these issues by continuously finding suitable strategies and developing new methods/materials that will potentially minimize CO2 emissions and eventually contribute to a healthy and sustainable future for the planet. The CO2 capturing requires the use of unique materials that possess inherent superior textural and surface properties or have been suitably functionalized to develop high adsorption capacities. Decades of research have indicated that different materials like activated carbon, metal–organic framework, aerogels, biomass-based nanomaterials (porous carbon), etc., fulfill the required texture and surface properties needed for CO2 capture and can be used as absorbents for CO2.