Search

Abstract Large-scale fabrication of neutron-shielding films with flexible or complex shapes is challenging. Uniform and high boron carbide (B4C) filler loads with sufficient workability are needed to achieve good neutron-absorption capacity. Here, we show that a two-dimensional (2D) Ti3C2T x MXene hybrid film with homogeneously distributed B4C particles exhibits high mechanical flexibility and anomalous neutron-shielding properties. Layered and solution-processable 2D Ti3C2T x MXene flakes serve as an ideal robust and flexible matrix for high-content B4C fillers (60 wt.%). In addition, the preparation of a scalable neutron shielding MXene/B4C hybrid paint is demonstrated. This composite can be directly integrated with various large-scale surfaces (e.g., stainless steel, glass, and nylon). Because of their low thickness, simple and scalable preparation method, and an absorption capacity of 39.8% for neutrons emitted from a 241Am– 9Be source, the 2D Ti3C2T x MXene hybrid films are promising candidates for use in wearable and lightweight applications.

Abstract A versatile use of a sulfur self‐doped biochar derived from Camellia japonica (camellia) flowers is demonstrated as a multifunctional catalyst for overall water splitting and a supercapacitor. The native sulfur content in the camellia flower facilitates in situ self‐doping of sulfur, which highly activates the camellia‐driven biochar (SA‐Came) as a multifunctional catalyst with the enhanced electron‐transfer ability and long‐term durability. For water splitting, an SA‐Came‐based electrode is highly stable and shows reaction activities in both hydrogen and oxygen evolution reactions, with overpotentials of 154 and 362 mV at 10 mA cm−2, respectively. For supercapacitors, SA‐Came achieves a specific capacitance of 125.42 F g−1 at 2 A g−1 and high cyclic stability in a three‐electrode system in a 1 M KOH electrolyte. It demonstrated a high energy density of 34.54 Wh kg−1 at a power density of 1600 W kg−1 as a symmetric hybrid supercapacitor device with a wide working potential range of 0–1.6 V.

Summary: Layered metallic transition metal dichalcogenides (MTMDs) exhibit distinctive electrical and catalytic properties to drive basal plane activity, and, therefore, they have emerged as promising alternative electrocatalysts for sustainable hydrogen evolution reactions (HERs). A key challenge for realizing MTMDs-based electrocatalysts is the controllable and scalable synthesis of high-quality MTMDs and the development of engineering strategies that allow tuning their electronic structures. However, the lack of a method for the direct synthesis of MTMDs retaining the structural stability limits optimizing the structural design for the next generation of robust electrocatalysts. In this review, we highlight recent advances in the synthesis of MTMDs comprising groups VB and VIB and various routes for structural engineering to enhance the HER catalytic performance. Furthermore, we provide insight into the potential future directions and the development of MTMDs with high durability as electrocatalysts to generate green hydrogen through water-splitting technology.

The unique physical and chemical properties of spinels have made them highly suitable electrocatalysts in oxygen evolution reaction and oxygen reduction reaction (OER & ORR). Zinc–air batteries (ZABs), which are safer and more cost-effective power sources than commercial lithium-ion batteries, hinge on ORR and OER. The slow kinetics of the air electrode reduce its high theoretical energy density and specific capacity, which limits its practical applications. Thus, tuning the performance of the electrocatalyst and cathode architecture is vital for improving the performance of ZABs, which calls for exploring spinel, a material that delivers improved performance. However, the structure–activity relationship of spinel is still unclear because there is a lack of extensive information about it. This study was performed to address the promising potential of spinel as the bifunctional electrocatalyst in ZABs based on an in-depth understanding of spinel structure and active sites at the atomic level.