Search

Molecular semiconductors (MSCs) are known as ideal candidates for constructing room‐temperature spin‐charge interactive devices due to their long spin lifetimes and abundant photoelectric properties. These devices can achieve novel and valuable functionalities such as room‐temperature supply units of fully spin‐polarized current. Unfortunately, their performances (sub‐0.1 nA) remain unsatisfactory due to limited charge and spin injection efficiency, which can hardly be improved despite great efforts thus far. Herein, from the theoretical side, an interfacial tunnel layer with precisely‐controlled barrier in spintronic devices may simultaneously enhance spin and charge injection. Accordingly, a solution‐processed small molecule with smooth morphology and amorphous structure is introduced to form a uniform and well‐controllable barrier in molecular spin‐photovoltaic devices. By modulating the thickness to effectively control the barrier, both spin and charge injection efficiency increase by > 150%. Thus, the spin‐charge interactive functionalities as supply units of fully spin‐polarized current have also been significantly improved than the current record at room temperature, the output fully spin‐polarized current (>2 nA) is 1200%‐larger, and the output power increases by > 50 times. Moreover, the interface‐modified spintronic devices exhibit excellent stability even after 70 days of exposure to air, which is essential for practical applications in the future. [ABSTRACT FROM AUTHOR]

Zeolitic imidazole frameworks (ZIFs) offer rich platforms for rational design and construction of high‐performance nonprecious‐metal oxygen reduction reaction (ORR) catalysts owing to their flexibility, hierarchical porous structures, and high surface area. Herein, an Fe, Cu‐coordinated ZIF‐derived carbon framework (Cu@Fe‐N‐C) with a well‐defined morphology of truncated rhombic dodecahedron is facilely prepared by introducing Fe2+ and Cu2+ during the growth of ZIF‐8, followed by pyrolysis. The obtained Cu@Fe‐N‐C, with bimetallic active sites, large surface area, high nitrogen doping level, and conductive carbon frameworks, exhibits excellent ORR performance. It displays 50 mV higher half‐wave potential (0.892 V) than that of Pt catalysts in an alkaline medium and comparable performance to Pt catalysts in an acidic medium. In addition, it also has excellent durability and methanol resistance ability in both acidic and alkaline solutions, which makes it one of the best Pt‐free catalysts reported to date for ORR. Impressively, when being employed as a cathode catalyst in zinc–air batteries, Cu@Fe‐N‐C presents a higher peak power density of 92 mW cm−2 than that of Pt/C (74 mW cm−2) as well as excellent durability. Fe, Cu‐coordinated zeolitic imidazole framework–derived carbon framework shows a superior oxygen reduction reaction performance with a half‐wave potential of 0.892 V, 50 mV higher than Pt/C, and excellent stability, resulting from bimetallic active sites, high active N content, and the mesoporous architecture. When employed as cathode catalyst, it also displays a good Zn–air battery performance. [ABSTRACT FROM AUTHOR]