D-Band Center Optimization of Edge-Rich Ultrathin RuZn Nanosheets With Moiré Superlattices for pH-Universal Hydrogen Evolution Reaction.

Electrocatalytic hydrogen evolution reaction (HER) is a promising way to produce pure and clean hydrogen. However, the preparation of efficient and economical catalysts for pH-universal HER remains a challenging but rewarding task. Herein, ultrathin RuZn nanosheets (NSs) with moiré superlattices and abundant edges are synthesized. The RuZn NSs with unique structure exhibit superb HER performance with overpotentials of 11, 13, and 29 mV to achieve 10 mA cm-2 in 1 M KOH, 1 M PBS, and 0.5 M H2 SO4 , respectively, which is substantially lower than those of Ru NSs and RuZn NSs without moiré superlattices. Density functional theory investigations reveal that the charge transfer from Zn to Ru will lead the appropriate downshift of the d-band center of surface Ru atoms, thus accelerating hydrogen desorption from the Ru sites, lowering the dissociation energy barrier of water and greatly improving the HER performance. This work provides an effective design scheme for high-performance HER electrocatalysts over a wide pH range, and propose a general route to prepare Ru-based bimetallic nanosheets with moiré superlattices.

Rapid Aqueous Synthesis of Large-Size and Edge/Defect-Rich Porous Pd and Pd-Alloyed Nanomesh for Electrocatalytic Ethanol Oxidation.

In this work, a facile aqueous synthesis strategy was used (complete in 5 min at room temperature) to produce large-size Pd, PdCu, and PdPtCu nanomeshes without additional organic ligands or solvent and the volume restriction of reaction solution. The obtained metallic nanomeshes possess graphene-like morphology and a large size of dozens of microns. Abundant edges (coordinatively unsaturated sites, steps, and corners), defects (twins), and mesopores are seen in the metallic ultrathin structures. The formation mechanism for porous Pd nanomeshes disclosed that they undergo oriented attachment growth along the ⟨111⟩ direction. Owing to structural and compositional advantages, PdCu porous nanomeshes with certain elemental ratios (e. g., Pd87 Cu13 ) presented enhanced electrocatalytic performance (larger mass activity, better CO tolerance and stability) toward ethanol oxidation.

Scalable Printing of Prussian Blue Analogue@Au Edge-Rich Microcubes as Flexible Biosensing Microchips Performing Ultrasensitive Sucrose Fermentation Monitoring.

Sucrose is one of the most applied carbon sources in the fermentation process, and it directly determines the microbial metabolism with its concentration fluctuation. Meanwhile, sucrose also plays a key role of a protective agent in the production of biological vaccines, especially in the new mRNA vaccines for curing COVID-19. However, rapid and precise detection of sucrose is always desired but unrealized in industrial fermentation and synthetic biology research. In order to address the above issue, we proposed an ultrasensitive biosensor microchip achieving accurate sucrose recognition within only 12 s, relying on the construction of a Prussian blue analogue@Au edge-rich (PBA@AuER) microarchitecture. This special geometric structure was formed through exactly inducing the oriented PBA crystallization toward a certain plane to create more regular and continuous edge features. This composite was further transformed to a screen-printed ink to directly and large-scale fabricate an enzymatic biosensor microchip showing ultrahigh sensitivity, a wide detection range, and a low detection limit to the accurate sucrose recognition. As confirmed in a real alcohol fermentation reaction, the as-prepared microchip enabled us to accurately detect the sucrose and glucose concentrations with outstanding reusability (more than 300 times) during the whole process through proposing a novel analytical strategy for the binary mixture substrate system.

Battery Separators Functionalized with Edge-Rich MoS2/C Hollow Microspheres for the Uniform Deposition of Li2S in High-Performance Lithium-Sulfur Batteries.

As promising energy storage systems, lithium-sulfur (Li-S) batteries have attracted significant attention because of their ultra-high energy densities. However, Li-S battery suffers problems related to the complex phase conversion that occurs during the charge-discharge process, particularly the deposition of solid Li2S from the liquid-phase polysulfides, which greatly limits its practical application. In this paper, edge-rich MoS2/C hollow microspheres (Edg-MoS2/C HMs) were designed and used to functionalize separator for Li-S battery, resulting in the uniform deposition of Li2S. The microspheres were fabricated through the facile hydrothermal treatment of MoO3-aniline nanowires and a subsequent carbonization process. The obtained Edg-MoS2/C HMs have a strong chemical absorption capability and high density of Li2S binding sites, and exhibit excellent electrocatalytic performance and can effectively hinder the polysulfide shuttle effect and guide the uniform nucleation and growth of Li2S. Furthermore, we demonstrate that the Edg-MoS2/C HMs can effectively regulate the deposition of Li2S and significantly improve the reversibility of the phase conversion of the active sulfur species, especially at high sulfur loadings and high C-rates. As a result, a cell containing a separator functionalized with Edg-MoS2/C HMs exhibited an initial discharge capacity of 935 mAh g-1 at 1.0 C and maintained a capacity of 494 mAh g-1 after 1000 cycles with a sulfur loading of 1.7 mg cm-2. Impressively, at a high sulfur loading of 6.1 mg cm-2 and high rate of 0.5 C, the cell still delivered a high reversible discharge capacity of 478 mAh g-1 after 300 cycles. This work provides fresh insights into energy storage systems related to complex phase conversions.