No abstract

The photocatalytic reduction of CO2 to energy carriers has emerged as one of the most promising strategies to alleviate the energy crisis and CO2 pollution, for which the development of catalyst was considered as the determining factor for the accomplishment of this conversion process. In this study, three stable and isostructural metal–organic frameworks (denoted as MOF-Ni, MOF-Co, and MOF-Cu) have been synthesized and used as heterogeneous catalysts in photocatalytic CO2 reduction reaction (CO2RR). It is worth noting that the MOF-Ni exhibited very high selectivity of 97.7% for photoreducing CO2 to CO, which has exceeded most of the reported MOF-based catalysts in the field. Significantly, the MOFs associated with a monometallic catalytic center offer a simple and precise structural model which allows us to understand more definitively the specific effects of different metal-ion species on photoreduction of CO2 as well as the reactive mechanism.

New porous anionic Ln-MOFs, namely, [MeNH][Ln(CPA)(HO)] (Ln = Eu, Gd), have been prepared through the self-assembly of 5-(4-carboxy phenyl)picolinic acid (HCPA) and lanthanide ions. They feature open anionic frameworks with 1-D hydrophilic channels and exchangeable dimethylamine ions. The Eu phase could detect Fe ions with high selectivity and sensitivity in either aqueous solution or biological condition. The ratios of lanthanide ions on this structure platform could be rationally tuned to not only achieve dichromatic emission colors with linear correlation but also attain three primary colors (RGB) and even white light with favorable correlated color temperature. Furthermore, the Ag(I)-exchanged phases can be readily reduced to afford Ag nanoparticles. The as-prepared Ag@Ln-MOFs composite shows highly efficient catalytic performance for the reduction of 4-nitrophenol.