Boosting photocatalytic CO2 reduction over a covalent organic framework decorated with ruthenium nanoparticles

The conversion of CO2 into valuable chemicals utilizing solar energy is one of the most promising approaches to solve the problems associated with global warming and energy shortage. Considering more and more covalent organic frameworks (COFs) that have been reported, the great potential of COFs as photocatalysts for CO2 reduction is still appreciated to a limited extent. In the current work, Ru nanoparticles (NPs) loaded ketoamine-based COF (TpPa-1) catalysts, named Ru/TpPa-1, were developed for the photocatalytic reduction of CO2 upon visible-light irradiation for the first time. Compared with TpPa-1, Ru/TpPa-1 catalysts exhibit a significantly enhanced activity for the photoreduction of CO2. In combination with the results from some extensive characterizations, it is found that the interactions between the Ru NPs and TpPa-1 can enhance the visible-light harvesting and create a new way to extend the service life of photo-generated charge carriers via facilitating the electron transfer through the loaded Ru NPs. The current investigation, therefore, provides a photocatalytic approach for CO2 fixation, enriches the theory of photocatalysis, and enlarges the application of COF-based materials.