Titanium metal-organic frameworks for photocatalytic CO 2 conversion through a cycloaddition reaction.

The elevated levels of CO 2 in the atmosphere have been a major concern for environmental scientists. Capturing CO 2 gas and its subsequent conversion to useful organic compounds is one of the avenues that have been extensively studied in the last decade. The photocatalytic cycloaddition of CO 2 is a promising approach for effective CO 2 capture and the production of value-added chemicals such as cyclic carbonates. MOF-901, a titanium-based metal-organic framework with hexagonal layers and imine linkages, was successfully oxidized in this study to MOF-997, incorporating amide linkages using Oxone. Both MOFs displayed remarkable photocatalytic activity in CO 2 cycloaddition under mild conditions, including moderate temperatures and visible light exposure. Particularly noteworthy is MOF-997, exhibiting superior performance with donor-acceptor active sites, achieving a 99.9% yield in catalyzing CO 2 conversion from styrene epoxide to styrene carbonate under solvent conditions.