Single-crystal ZrCo nanoparticle for advanced hydrogen and H-isotope storage.

Hydrogen-isotope storage materials are essential for the controlled nuclear fusion. However, the currently used smelting-ZrCo alloy suffers from rapid degradation of performance due to severe disproportionation. Here, we reveal a defect-derived disproportionation mechanism and report a nano-single-crystal strategy to solve ZrCo's problems. Single-crystal nano-ZrCo is synthesized by a wet-chemistry method and exhibits excellent comprehensive hydrogen-isotope storage performances, including ultrafast uptake/release kinetics, high anti-disproportionation ability, and stable cycling, far superior to conventional smelting-ZrCo. Especially, a further incorporation of Ti into nano-ZrCo can almost suppress the disproportionation reaction. Moreover, a mathematical relationship between dehydrogenation temperature and ZrCo particle size is established. Additionally, a microwave method capable of nondestructively detecting the hydrogen storage state of ZrCo is developed. The proposed disproportionation mechanism and anti-disproportionation strategy will be instructive for other materials with similar problems.

Honeycomb ZrCo Intermetallic for High Performance Hydrogen and Hydrogen Isotope Storage.

Hydrogen isotope storage materials are of great significance for controlled nuclear fusion, which is promising to provide unlimited clean and dense energy. Conventional storage materials of micrometer-sized polycrystalline ZrCo alloys prepared by the smelting method suffer from slow kinetics, pulverization, disproportionation, and poor cycling stability. Here, we synthesize a honeycomb-structured ZrCo composed of highly crystalline submicrometer ZrCo units using electrospray deposition and magnesiothermic reduction. Compared with conventional ones, honeycomb ZrCo does not require activation and exhibits more than 1 order of magnitude increase in kinetic property. Owing to low defects and low stress, the anti-disproportionation ability and cycling stability of honeycomb ZrCo are also obviously higher than those of conventional ZrCo. Moreover, the interfacial stress (due to hydrogenation/dehydrogenation) as a function of particle radius is established, quantitatively elucidating that small-sized ZrCo reduces stress and pulverization. This study points out a direction for the structural design of ZrCo alloy with high-performance hydrogen isotope storage.

MXene-Reinforced Liquid Metal/Polymer Fibers via Interface Engineering for Wearable Multifunctional Textiles.

Stretchable conductive fibers are an important component of wearable electronic textiles, but often suffer from a decrease in conductivity upon stretching. The use of liquid metal (LM) droplets as conductive fillers in elastic fibers is a promising solution. However, there is an urgent need to develop effective strategies to achieve high adhesion of LM droplets to substrates and establish efficient electron transport paths between droplets. Here, we use large-sized MXene two-dimensional conductive materials to modify magnetic LM droplets and prepare MXene/magnetic LM/poly(styrene-butadiene-styrene) composite fibers (MLMS fibers). The MXene sheets decorated on the surface of magnetic LM droplets not only enhance the droplet adhesion to substrate but also bridge adjacent droplets to establish efficient conductive paths. MLMS fibers show several-fold improvements in tensile strength and elongation and a 30-fold increase in conductivity compared with pure LM-filled fibers. These conductive fibers can be easily woven into multifunctional textiles, which exhibit strong electromagnetic interference shielding and stable Joule heating performances even under large tensile deformation. In addition, other advantages of MLMS textiles, such as high gas/liquid permeability, strong chemical resistance (acid and alkaline conditions), high/low-temperature tolerance (-40-150 °C) and water washability, make them particularly suitable for wearable applications.

The synergistic effect of Co/Ni in ultrathin metal-organic framework nanosheets for the prominent optimization of non-enzymatic electrochemical glucose detection.

Hybrid metal compounds have been paid increasing attention for the development of electroanalysis materials due to the specific collaboration interaction and synergy effect of metal elements. Herein, a series of ultrathin Ni/Co bimetallic metal-organic-framework nanosheets (UMOFNs) with different metal ratios were investigated as high-performance electroanalysis materials for non-enzymatic glucose electrochemical sensing. The synergistic effect between Ni/Co endowed UMOFNs with not only the unique electrochemical behavior that prompts the sensing-related electrochemical oxidation at a low applied potential, but also the enhanced affinity to glucose; also, they facilitated the electron transfer involving the analyte. The UMOFN composite with an elaborately adjusted Co/Ni ratio exhibits an extremely outstanding glucose sensing performance, including high sensitivity (2086.7 µA mM-1 cm-2), wide linear range (0.1 µM-1.4 mM), low detection limit (0.047 µM), and excellent selectivity. It can also be used for the detection of glucose in actual human serum samples with an accuracy of 90.1%, demonstrating a good application prospect of the non-enzymatic electrochemical glucose detection.

Electrophoresis-Deposited Mesoporous Graphitic Carbon Nitride Surfaces with Efficient Bactericidal Properties.

With the rise of bacterial infections and antimicrobial resistance, it is important to develop environmentally friendly functional materials and surfaces with efficient bactericidal activity. In this work, nanostructured graphitic carbon nitride (g-C3N4) surfaces were fabricated by electrophoresis deposition of mesoporous g-C3N4 materials. Efficient bactericidal performance was achieved through the synergistic biophysical interaction of bacterial cells with the nanotopographies and visible light active photocatalytic properties. The nanotopographies of g-C3N4 surfaces demonstrated a "contact-killing" efficiency of >90% against Pseudomonas aeruginosa and >80% against Staphylococcus aureus cells. The number of surviving bacteria on the surfaces further decreased remarkably upon illumination using visible light generated by a light-emitting diode lamp with an irradiation intensity of 12.4 mW cm-2. In total, the number of viable bacteria was reduced by approximately 3 orders of magnitude for P. aeruginosa and 2 orders of magnitude for S. aureus. Our experimental findings provide potential prospects for developing highly efficient photocatalytic bactericidal surfaces.

Surface Engineering for Extremely Enhanced Charge Separation and Photocatalytic Hydrogen Evolution on g-C3 N4.

Reinforcing the carrier separation is the key issue to maximize the photocatalytic hydrogen evolution (PHE) efficiency of graphitic carbon nitride (g-C3 N4 ). By a surface engineering of gradual doping of graphited carbon rings within g-C3 N4 , suitable energy band structures and built-in electric fields are established. Photoinduced electrons and holes are impelled into diverse directions, leading to a 21-fold improvement in the PHE rate.