Nanomaterials and hybrid nanocomposites for CO capture and utilization: environmental and energy sustainability.

Anthropogenic carbon dioxide (CO) emissions have dramatically increased since the industrial revolution, building up in the atmosphere and causing global warming. Sustainable CO capture, utilization, and storage (CCUS) techniques are required, and materials and technologies for CO capture, conversion, and utilization are of interest. Different CCUS methods such as adsorption, absorption, biochemical, and membrane methods are being developed. Besides, there has been a good advancement in CO conversion into viable products, such as photoreduction of CO using sunlight into hydrocarbon fuels, including methane and methanol, which is a promising method to use CO as fuel feedstock using the advantages of solar energy. There are several methods and various materials used for CO conversion. Also, efficient nanostructured catalysts are used for CO photoreduction. This review discusses the sources of CO emission, the strategies for minimizing CO emissions, and CO sequestration. In addition, the review highlights the technologies for CO capture, separation, and storage. Two categories, non-conversion utilization (direct use) of CO and conversion of CO to chemicals and energy products, are used to classify different forms of CO utilization. Direct utilization of CO includes enhanced oil and gas recovery, welding, foaming, and propellants, and the use of supercritical CO as a solvent. The conversion of CO into chemicals and energy products chemical processes and photosynthesis is a promising way to reduce CO emissions and generate more economically valuable chemicals. Different catalytic systems, such as inorganics, organics, biological, and hybrid systems, are provided. Lastly, a summary and perspectives on this emerging research field are presented.