ABSTRACT Intercalation has been considered as an effective method to explore innovative two-dimensional (2D) materials and modify their properties. However, the relationship between intercalation concentration, structure, and property remains a largely uncharted territory, and the controllable synthesis of desired intercalated phases faces challenges. Here, a general intercalated rule for the effect of self-intercalation ratio on atomic arrangements is revealed. Then, the controllable synthesis of a series of Fe-intercalated 2D materials is realized. Scanning transmission electron microscopy illustrates that their intercalation structures undergo disordered/ordered/half-ordered/ordered transformation, which confirms the intercalated rule and proposes a new structure termed half-ordered intercalation. Notably, their magnetic and electrical properties can be significantly modulated by intercalation. Orderly intercalated nanoflakes possess room-temperature magnetism with composition-regulated magnetic domains. Moreover, Fe1.5Se2 and Fe1.6Se2 are scarce half-metallic materials showing different magneto-resistance behaviors. This work would guide the design and synthesis of new intercalated materials, and deepen the understanding of the relationship between structure and properties.
A new type of tip timing sensor is described. The conglomeration of the light and the high efficiency collection of the light dispersed can be realized by means of Y type coupling optic fiber and self focusing lens, with the result that the sensitivity of detection is greatly improved. In addition, using a 45 mW semiconductor laser as lamp house and an avalanche photodiode as optic electronic receiver, the sensor has many advantages of small and simple structure, high measuring precision , easy adjustment and installation and low cost. The simulation experiment shows that the sensor does well in receiving signal, and is suitable for high speed and real time detection of turbo machinery blade. It can provide stable and credibility signal for subsequent disposing circuit.
In order to understand a structure and property of Ni_Co_B amorphous alloys,a series of cluster models Ni 4-m Co m B (m=0-3) are chosen according to structure characters of short_range_ordering in the amorphous alloys.These cluster models are calculated with DFT method and the results of the calculations show that Co_B bond is stronger than Ni_B bond,and the cobalt added modifty a electric structure of nickel in Ni_Co_B amorphous alloys.
We report the exploration of all-inorganic perovskite photodetectors based on stabilized CsPb0.922Sn0.078I3 nanobelts, which exhibit overall excellent performance with an ultrahigh detectivity up to 6.43 × 1013 Jones.
An entry from the Inorganic Crystal Structure Database, the world’s repository for inorganic crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the joint CCDC and FIZ Karlsruhe Access Structures service and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Abstract Currently, it is still a significant challenge to simultaneously boost various reactions by one electrocatalyst with high activity, excellent durability, as well as low cost. Herein, hybrid trifunctional electrocatalysts are explored via a facile one‐pot strategy toward an efficient oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER). The catalysts are rationally designed to be composed by FeCo nanoparticles encapsuled in graphitic carbon films, Co 2 P nanoparticles, and N,P‐codoped carbon nanofiber networks. The FeCo nanoparticles and the synergistic effect from Co 2 P and FeCo nanoparticles make the dominant contributions to the ORR, OER, and HER activities, respectively. Their bifunctional activity parameter (∆ E ) for ORR and OER is low to 0.77 V, which is much smaller than those of most nonprecious metal catalysts ever reported, and comparable with state‐of‐the‐art Pt/C and RuO 2 (0.78 V). Accordingly, the as‐assembled Zn–air battery exhibits a high power density of 154 mW cm −2 with a low charge–discharge voltage gap of 0.83 V (at 10 mA cm −2 ) and excellent stability. The as‐constructed overall water‐splitting cell achieves a current density of 10 mA cm −2 (at 1.68 V), which is comparable to the best reported trifunctional catalysts.
The fixation of carbon dioxide (CO2) directly from flue gas into valuable chemicals like 2-oxazolidinones is of great significance for economic and environmental benefits, which is typically catalyzed by noble-metal catalysts and under harsh conditions. Herein, a novel 2-fold interpenetrated framework {[Co3(μ2-O)(TCA)2(HDPTA)2]·2H2O·2DMF}n [Co(II)-based metal-organic framework (Co-MOF)] containing [Co3] clusters and highly dense amino groups (-NH2) dispersed in the channel was prepared, exhibiting high solvent/pH stability and CO2 adsorption capacity (24.9 cm3·g-1). Catalytic experiments demonstrated that Co-MOF could catalyze the carboxylative cyclization of propargylic amines to generate 2-oxazolidinones with yields of up to 98% under mild conditions with CO2 directly from flue gas. In addition, Co-MOF retained its structure and catalytic activity after five-cycle catalytic experiments, showing the promising practical application. Density functional theory (DFT) calculation suggested that the [Co3] centers in the MOF activated the C≡C of propargylic amines with much more binding energy than Co(NO3)2, partly accounting for the high catalytic activity of Co-MOF. This work demonstrates the first Co-based MOF material that is highly efficient for carboxylative cyclization of propargylic amines with flue gas as the CO2 source, inspiring further rational design of porous catalysts for efficient CO2 utilization.
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