ABSTRACT
The design and construction of three-dimensional covalent organic frameworks (3D COF) remains a major challenge, and it is necessary to explore new strategies to synthesize 3D COF with ideal structure. Here, we utilize two-dimensional covalent organic framework (2D COF) with allyl side chain to achieve interlayer crosslinking through olefin metathesis reaction, thereby constructing a 3D COF with cage-like structures. This new material named CAGE-COF has larger specific surface area and more open pore structure than the original 2D COF. The cathode material with CAGE-COF retained 78.7% of its initial capacity after 500 cycles, and the fading rate is 0.04% each cycle.
Subject(s)
Lithium , Metal-Organic Frameworks , Electrodes , Alkenes , Electric Power Supplies , SulfurABSTRACT
Single-matrix white light-emitting diodes are still a challenge. Achieving tunable white light emission from lead-free perovskites attracts much attention. Herein, nanoscale Rb2SnCl6 (RSC) vacancy ordered double perovskite were synthesized by an optimized precipitation method. Further, using ns2 ions (Bi3+, Te4+, and Sb3+) doped RSC vacancy ordered double perovskite to obtain broadband blue, yellow-green, and orange-red emission. The color temperature adjustable high-quality white light emission based on the codoping strategy is obtained by controlling the doping ratio of Bi3+ and Te4+. Additionally, the white light-emitting diodes encapsulated by this single matrix white luminescent material exhibit excellent stability. Combined with theoretical calculations, it is elucidated that these high-efficiency emissions are not only derived from the unique electronic transition of ns2 ions but also related to the energy band properties and the crystal field. This work shows that ns2 ions doped RSC vacancy ordered double perovskite can meet the needs of different luminous colors and color temperature tunable white light emission. Meanwhile, it is a strong competitor to replace the lead-based perovskite.