Light-Assisted CO₂ Cycloaddition over a Nanochannel Cadmium–Organic Framework Loaded with Silver Nanoparticles

Compared to conventional thermal-driven fixation, the light-assisted CO 2 fixation into useful chemicals represents a viable strategy for environmental restoratio n and energy sustainability. Hence, in this work, the type of linker was tuned to control the structure and topology of metal–organic frameworks (MOFs), resulting in a diversity of pore networks ranging from two-dimensional (2D) microporous channels ( NWU-Cd1, 2 ) to three-dimensional (3D) nanochannels ( NWU-Cd3 ). Among them, NWU-Cd3 can be employed as a reducing agent to convert Ag(I) ions to Ag(0) to generate Ag/ NWU-Cd3 composite materials in situ due to its large pore size, high CO 2 adsorption capacity, and redox activity. Ag/ NWU-Cd3 can expand the absorption spectrum to the visible area, and it exhibits excellent photocatalytic activity with the yield of styrene carbonate up to 94.3% at light irradiation and room temperature, which is 5.2 times of that under dark conditions. Notably, each Ag NP of the MOF network functions concurrently as a photosensitizer (harvesting light and producing electrons) and a cocatalyst (serving as the Lewis acid). The plasmonic hot electrons can gather on the Ag NP surface under light irradiation and rapidly transfer to NWU-Cd3 to interact with CO 2, resulting in activated CO 2 *. Simultaneously, the presence of Ag NPs provides an action site for epoxides and accelerates the ring-opening process, and thus, Ag/ NWU-Cd3 displays high catalytic reactivity for CO 2 cycloaddition under mild circumstances (25 °C, 1 atm). This research clarifies the conjunction of light and Ag NPs in accelerating CO 2 conversion and offers a substitutable method to further devise effective heterogeneous catalysts for light-induced CO 2 cycloaddition.