A new pure fluorescent blue HLCT-emitter was designed and synthesized. Highly efficient non-doped blue OLEDs with low efficiency roll-off were achieved.

A Pure blue light-emitting material is one of the key materials for the preparation of organic light-emitting diodes (OLEDs) displays. Although high-efficiency blue OLEDs have been realized in thermally activated delayed-fluorescence (TADF) materials, they cannot but scattered into suitable host materials. Hence, exploring efficient nonndoped pureblue-luminous molecules is important. Herein, a novel "hot-exciton" material, 4-(2-(4-(10-(4-(3,6-di-tert-butyl-9Hcarbazol-9-yl)phenyl)anthracen-9-yl)phenyl)-1H-phenanthro[9,10-d]imidazol-1-yl)benzonitrile (tBuPCAPICN) is reported for the application of pure-blue fluorescent OLEDs. The nondoped tBuPCAPICN-based OLED exhibited excellent pureblue electroluminescence (EL) performance with a peak of emission at 452 nm and a full width at half maximum (FWHM) of only 53 nm, corresponding to the Commission Internationale de l'Eclairage (CIE) coordinates of (0.15, 0.11). Furthermore, the maximum external quantum efficiency (EQE) of the OLED reached 12.7%, and the exciton utilization efficiency (EUE) approached 80%, ranking among the upmost outcomes in nondoped pure-blue OLEDs. The distinguished EL performance could ascribe to the coordination of high molecular horizontal orientation (orientation factor Θ ≈ 82%) and high energy triplet exciton utilization. This work doesn't merely reveal application potential of the tBuPCAPICN in pure-blue OLEDs, but also offers a useful approach for designing novel fluorescent materials with high-efficiency pure-blue performance.

With the continuous development of nuclear energy, the radioactive iodine in nuclear waste is becoming more and more harmful to environmental pollution and human health. Here, we synthesized two ionic...

Tuning the metal‐support interaction of supported metal catalysts has been found to be the most effective approach to modulating electronic structure and improving catalytic performance. But practical understanding of the charge transfer mechanism at the electronic level of catalysis process has remained elusive. Here, it is reported that ruthenium (Ru) nanoparticles can self‐accommodate into Fe3O4 and carbon support (Ru‐Fe3O4/C) through the electronic metal‐support interaction, resulting in robust catalytic activity toward the alkaline hydrogen evolution reaction (HER). Spectroscopic evidence and theoretical calculations demonstrate that electronic perturbation occurred in the Ru‐Fe3O4/C, and that charge redistribution directly influenced adsorption behavior during the catalytic process. The RuO bond formed by orbital mixing changes the charge state of the surface Ru site, enabling more electrons to flow to H intermediates (H*) for favorable adsorption. The weak binding strength of the RuO bond also reinforces the anti‐bonding character of H* with a more favorable recombination of H* species into H2 molecules. Because of this satisfactory catalytic mechanism, the Ru‐Fe3O4/C supported nanoparticle catalyst demonstrated better HER activity and robust stability than the benchmark commercial Pt/C benchmark in alkaline media.

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