The ability to expose MOF pores on demand using visible light has been demonstrated and exploited for the capture and release of carbon dioxide. Coating of Mg-MOF-74 or MIL-53(Al) with methyl red dye afforded composite materials that became able to adsorb carbon dioxide after exposure to visible light. The Mg-MOF-74 series can be tailored to an 84% uptake change upon irradiation, which is an attractive low-energy alternative for CO2 capture, where the reliance on coal-based power for materials generation is reduced. Kinetic and temperature dependent studies highlighted the mechanism behind this new effect in MOFs, which varied according to the structural rigidity of the framework. © 2015 American Chemical Society.