The capacity of anode materials plays a critical role in the performance of lithium-ion batteries. Using the nanocrystals of oxygen-free metal-organic framework ZIF-67 as precursor, a one-step calcination approach toward the controlled synthesis of CoO nanoparticle cookies with excellent anodic performances is developed in this work. The CoO nanoparticle cookies feature highly porous structure composed of small CoO nanoparticles (≈12 nm in diameter) and nitrogen-rich graphitic carbon matrix (≈18 at% in nitrogen content). Benefiting from such unique structure, the CoO nanoparticle cookies are capable of delivering superior specific capacity and cycling stability (1383 mA h g(-1) after 200 runs at 100 mA g(-1) ) over those of CoO and graphite.

• Shear wave elastography (SWE) is a group of novel ultrasound-based technologies. • Meta-analysis was employed to assess relevant studies of SWE of thyroid nodules. • SWE had high sensitivity and specificity in identifying malignant thyroid nodules. • The high negative predictive value of SWE can reduce unnecessary biopsies.

Nanoreactors constructed by encapsulation of catalytic species in hierarchically porous metal–organic framework (HPMOF) nanostructures have emerged as a type of promising catalysts that deliver enhanced conversion and excellent selectivity/stability. However, the controlled synthesis of small HPMOF nanocrystals with tunable size and nanostructures remains challenging. Here, by coupling external ultrasonication with the inherent binding competitions between the metal ions of bimetallic Co/Zn-ZIF, we design and develop a new strategy, dynamic growth, for the facile synthesis of small (down to ca. 95 nm), single-crystalline and structure-/size-tunable HPMOF nanocrystals through a one-pot, additive-free procedure. Benefiting from the combined structure/size regulation, nanoreactors based on our small nanocrystals of meso-HP-Co/Zn-ZIF-50% are able to deliver exceptional conversion while keeping their excellent selectivity and stability. Insights gained from this work opens a new avenue for the development of complex/dynamic coordination materials in which the compositions, structures, properties, and functions can be designed/tuned through the coupling of their inherent binding competitions with external stimuli.

The development of cost-effective, high-performance , and robust bifunctional electrocatalysts for overall water splitting remains highly desirable yet quite challenging. Here, by selecting appreciate precursors of dopamine and a Co-containing metal−organic framework of ZIF-67, we subtly couple their reaction processes to develop a facile approach for the synthesis of a hollow CoP nanostructure with N-doped carbon skeleton (H-CoP@NC). Benefiting from the highly porous nanostructure and conductive carbon skeleton, H-CoP@NC is capable of working as highly active and durable bifunctional electrocatalyst for both hydrogen and oxygen evolution reaction. When further used as the electrocatalyst for overall water splitting, H-CoP@NC delivers excellent activity cell voltage of 1.72 V at a current density of 10 mA cm−2), close to that of the noble-metal-based benchmark catalyst couple of Pt/C||RuO2. Our work thus provides new insights into the development of transitional metal phosphides based hollow hybrid nanostructures, particularly those with multiple functionalities in sustainable energy conversion technologies and systems.

The development and enrichment of high‐performance organic fluorophores that simultaneously possess thermally activated delayed fluorescence (TADF) and aggregation‐induced emission (AIE) properties is going pursued but remains a great challenge due to severe exciton quenching. Herein, a systematical investigation on imidazole moiety has successfully given rise to a series of highly efficient imidazole‐based TADF‐AIE luminogens for the first time. The attachment of two cyano functionalities on imidazole moiety can significantly increase the electron‐withdrawing ability, so as to realize TADF emissions with small singlet‐triplet energy gaps (ΔEST) values. Meanwhile, the installation of a steric hindrance group at N1 position of imidazole moiety can twist the geometry between imidazole and phenyl bridge, thus transforming imidazole derivative from an aggregation‐caused quenching emitter into an AIE luminogen. Consequently, the non‐doped organic light‐emitting diodes (OLEDs) utilizing these TADF‐AIE luminogens as emitters exhibit outstanding sky‐blue and green emissions, with external quantum efficiency (EQE) as high as 20.0% and low efficiency roll‐off (EQE at 1000 cd m−2, 16.1%). These values represent the state‐of‐the‐art performance for all imidazole‐based OLED devices, which illustrates the significant potential of imidazole derivatives in assembling high‐performance OLEDs.