The pursuit of high reversible capacity and long cycle life for rechargeable batteries has gained extensive attention in recent years, and the development of applicable electrode materials is the key point. Herein, thanks to the preintercalation of lithium ions, a stable and highly conductive nanostructure of V2C MXene is successfully fabricated via a facile self‐discharge mechanism, which provides open spaces for rapid ion diffusion and guarantees fast electron transport. Taking the prelithiated V2C as electrode, an outstanding initial coulombic efficiency of 80% and an impressive capacity retention of ≈98% after 5000 charge/discharge cycles are achieved for lithium‐ion batteries. Especially, it demonstrates a fascinating reversible capacity of up to 230.3 mA h g−1 at 0.02 A g−1 and a long cycling life of 82% capacity retention over 480 cycles in the hybrid magnesium/lithium‐ion batteries. In addition, the Mg2+ and Li+ ions cointercalation mechanism of the prelithiated V2C is elucidated through ex situ X‐ray diffraction and X‐ray photoelectron spectroscopy characterizations. This work not only offers an effective approach to compensate the large initial lithium loss of high‐capacity anode materials but also opens up a new and viable avenue to develop promising hybrid Mg/Li‐storage materials with eminent electrochemical performance.

No abstract

No abstract

A process for fabricating three‐dimensional photonic crystals composed of SiO2–TiO2‐based ceramics with a diamond structure was investigated. An epoxy structure having an inverse diamond configuration was fabricated by stereolithography, a rapid prototyping method. The epoxy structure was infiltrated with a ceramic slurry and then cold isostatically pressed. After sintering at 670°C for 5 h in air, the epoxy was burned off, leaving behind the desired structure of a ceramic photonic crystal. The calculated band diagram indicated that an absolute photonic band gap for all wave vectors existed. The measurement of transmission in the 〈100〉 direction from 10 to 20 GHz showed that a complete band gap formed at about 14.7–18.5 GHz. The magnitude of the maximum attenuation was as large as 30 dB at 17 GHz, which indicated that the fabricated structure worked well as a photonic crystal.

No abstract

No abstract

No abstract

Benefiting from ordered atomic structures and strong d‐orbital interactions, intermetallic compounds (IMCs) are promising electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Herein, the body‐centered cubic IrGa IMCs with atomic donor–acceptor architectures are synthesized and anchored on the nitrogen‐doped reduced graphene oxide (i.e., IrGa/N‐rGO). Structural characterizations and theoretical calculations reveal that the electron‐rich Ir sites are atomically dispersed in IrGa/N‐rGO, facilitating the electron transfer between Ir atoms and adsorbed species, which can efficiently decrease the energy barriers of the potential determining step for both HER and OER. Impressively, the IrGa/N‐rGO||IrGa/N‐rGO exhibits excellent performance for overall water splitting in alkaline medium, requiring a low cell voltage of 1.51 V to achieve 10 mA cm−2, meanwhile, exhibiting no significant degradation for 100 h. This work demonstrates that the rational design of noble metal electrocatalysts with donor–acceptor architectures is beneficial for catalytic reactions in energy conversion applications.