Owing to their rich porosity and structural diversity, metal–organic frameworks (MOFs) offer substantial advantages over other emission sources for the precise design and color regulation of white-light phosphors. However, achieving efficient white-light emission remains a considerable challenge. Herein, we report a strategy to achieve tunable and efficient white-light emission by regulating energy transfer in a multicomponent dye-loaded MOF. An anionic MOF NKU-114 featuring appropriate confined spaces is designed as a host to deliberately encapsulate three red-, green-, and blue-emissive dyes with adaptive spectral overlap, DSM, AF, and 9-AA, respectively, yielding the NKU-114@dyes composites. Integrating the suitable spectral overlap and efficient energy transfer between the dyes and the framework produced a white-light emission material containing the multicomponent dyes NKU-114@DSM/AF/9-AA. The obtained material has a broadband white emission with a high quantum yield (up to 42.07%) and nearly identical CIE coordinates of (0.34, 0.32), and the moderate correlated color temperature and color-rendering index value can reach up to 5101 K and 81, respectively, suggesting the potential of the multicomponent dye-loaded MOF for white-light-emitting phosphors with good color quality.

Single-atom catalysts (SACs) have garnered enormous interest due to their remarkable catalysis activity. However, the exploitation of universal synthesis strategy and regulation of coordination environment of SACs remain a great challenge. Herein, a versatile synthetic strategy is demonstrated to generate a series of transition metal SACs (M SAs/NC, M = Co, Cu, Mn; NC represents the nitrogen-doped carbon) through defect engineering of metalorganic frameworks (MOFs). The interatomic distance between metal sites can be increased by deliberately introducing structural defects within the MOF framework, which inhibits metal aggregation and consequently results in an approximately 70% increase in single metal atom yield. Additionally, the coordination structures of metal sites can also be facilely tuned. The optimized Co SAs/NC-800 exhibits superior activity and excellent reusability for the selective hydrogenation of nitroarenes, surpassing several state-of-art non-noble-metal catalysts. This study provides a new avenue for the universal fabrication of transition metal SACs.

Lanthanide metal-organic frameworks (Ln-MOFs) are promising for luminescence detection of volatile organic compound (VOC) vapors, but usually suffer from the silent or quenched Ln 3 + emission. Herein, we report a new dual-emissive Eu-MOF composed of the coordinatively unsaturated Eu 9 clusters that afford abundant open metal sites to form a confined "binding pocket" to facilitate the preconcentration and recognition of VOCs. Single-crystal structural analyses reveal that specific analytes can replace the OH oscillators in the first coordination sphere of Eu 3 + and form a unique hydrogen-bonding second-sphere adduct tying adjacent Eu 9 clusters together to minimize their nonradiative vibrational decay. With the promoted Eu 3 + luminescence, the MOF realizes real-time in situ visual sensing of THF vapor (< 1 s) and shows a quantitative ratiometric response to the vapor pressure with a limit of detection down to 17.33 Pa. Also, it represents a topperforming ratiometric luminescent thermometer.

Scheme 1. Schematic overview on the construction of LP@MOFs materials and their optical applications.

A redox-active tetrazine moiety is immobilized within a metal-organic framework (MOF) aiming at targeted construction of a cathode with improved performance for lithium-oxygen batteries. A 1,2,4,5-tetrazine (Tz) functionalized ligand is used to construct a nanoporous MOF, Tz-Mg-MOF-74, in which the redox activity of the Tz moiety is retained. Combining the redox activity of Tz with the porous nature of a MOF produced a Tz-Mg-MOF-74-based cathode with significantly improved electrochemical performance. Specifically, the material has improved sustainable capacity with a lower overpotential compared with otherwise similar batteries without Tz and other reported MOF-based catalysts. The present approach productively integrates electrochemical activity derived from redox-active moieties and MOFs, and this combination opens a new avenue for the design of effective materials for energy storage and conversion.