Chelate-Capped Nano-AgZn3 Dual Interphase Remodeling the Local Environment for Reversible Dendrite-Free Zinc Anode.

Rechargeable aqueous zinc-ion batteries (AZIBs) are among the most promising candidates for next-generation energy-storage devices. However, the large voltage polarisation and infamous dendrite growth hinder the practical application of AZIBs owing to their complex interfacial electrochemical environment. In this study, a hydrophobic zinc chelate-capped nano-silver (HZC-Ag) dual interphase is fabricated on the zinc anode surface using an emulsion-replacement strategy. The multifunctional HZC-Ag layer remodels the local electrochemical environment by facilitating the pre-enrichment and de-solvation of zinc ions and inducing homogeneous zinc nucleation, thus resulting in reversible dendrite-free zinc anodes. The zinc deposition mechanism on the HZC-Ag interphase is elucidated by density functional theory (DFT) calculations, dual-field simulations, and in situ synchrotron X-ray radiation imaging. The HZC-Ag@Zn anode exhibited superior dendrite-free zinc stripping/plating performance and an excellent lifespan of >2000 h with ultra-low polarisation of ≈17 mV at 0.5 mA cm-2 . Full cells coupled with a MnO2 cathode showed significant self-discharge inhibition, excellent rate performance, and improved cycling stability for >1000 cycles. Therefore, this multifunctional dual interphase may contribute to the design and development of dendrite-free anodes for high-performance aqueous metal-based batteries.

Aerophilic Triphase Interface Tuned by Carbon Dots Driving Durable and Flexible Rechargeable Zn-Air Batteries.

Efficient bifunctional catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are vital for rechargeable Zn-air batteries (ZABs). Herein, an oxygen-respirable sponge-like Co@C-O-Cs catalyst with oxygen-rich active sites was designed and constructed for both ORR and OER by a facile carbon dot-assisted strategy. The aerophilic triphase interface of Co@C-O-Cs cathode efficiently boosts oxygen diffusion and transfer. The theoretical calculations and experimental studies revealed that the Co-C-COC active sites can redistribute the local charge density and lower the reaction energy barrier. The Co@C-O-Cs catalyst displays superior bifunctional catalytic activities with a half-wave potential of 0.82 V for ORR and an ultralow overpotential of 294 mV at 10 mA cm-2 for OER. Moreover, it can drive the liquid ZABs with high peak power density (106.4 mW cm-2), specific capacity (720.7 mAh g-1), outstanding long-term cycle stability (over 750 cycles at 10 mA cm-2), and exhibits excellent feasibility in flexible all-solid-state ZABs. These findings provide new insights into the rational design of efficient bifunctional oxygen catalysts in rechargeable metal-air batteries.

Interfacial-Shear-Mediated Snowball Assembly of Hotspot-Rich Silver Pompon Architectures for Tailored Surface-Enhanced Raman Scattering Responses.

To gain superior signal-enhanced performance, metal nanocrystals serving as building blocks can be collectively assembled into a hierarchically ordered structure for creating multiple hotspots. However, the collaborative assembly of anisotropic crystals to form a hotspot-rich structure remains a challenging task. In this study, controllable shear was introduced to a soft liquid-liquid interface to provide a unique environment for the snowball assembly of silver pompon architectures (Ag-PAs). Micrometer-scale 3D plasmonic Ag pompon architectures composed of densely packed nanoparticles (NPs) are fabricated using shear-mediating crystal growth dynamics. The crystal morphology and size are easily controlled by tuning the interfacial shear and diffusion pathways. The hotspot-rich Ag-PAs with high sensitivity (LOD = 1.1 × 10-13 mol/L) exhibit a superior Raman enhancement performance, which is comparable to some bimetals.

Hydrophobic plasmonic silver membrane as SERS-active catcher for rapid and ultrasensitive Cu(II) detection.

The rapid and selective identification of heavy metal ions is crucial for environmental water safety. In this study, a novel surface-enhanced Raman scattering (SERS)-active catcher was designed for Cu(II) detection using a hydrophobic hydroxyoxime-mediated plasmonic silver membrane (HOX@Ag-PVDF). Uniformly dispersed Ag nanoparticles (ca. 80 nm) and hydroxyoxime molecules were synchronously decorated on the skeleton of the polyvinylidene fluoride membrane via an in situ interfacial assembly strategy. HOX@Ag-PVDF shows excellent SERS activity (EF = 2.5 × 107), high reproducibility (~8% RSD), and long-term stability (50 days) for detecting 4-nitrothiophenol (4-NTP). Moreover, HOX@Ag-PVDF can serve as a new platform for rapid and dry-free SERS detection of Cu(II) owing to its strong affinity and surface hydrophobicity. Cu(II) ions can be rapidly captured in 5 s and selectively recognized by SERS signals without interference from other metal ions. HOX@Ag-PVDF exhibits linear SERS response signals at low concentrations ranging from 10-6 to 10-10 mol/L Cu(II) (R2 = 0.9893) with a low detection limit (LOD) of 52.0 pmol/L. This hydrophobic plasmonic membrane, with its simple sampling and rapid SERS response characteristics, provides ultrasensitive recognition and heavy metal detection for practical applications.

Coral-like carbon-wrapped NiCo alloys derived by emulsion aggregation strategy for efficient oxygen evolution reaction.

The transition metal-based catalysts have great potential to boost the electrocatalytic reactions due to their flexible electronic configuration and low cost. This work developed a facile emulsion aggregation strategy to synthesize coral-like carbon-wrapped NiCo alloy (Co0.5Ni0.5/rGO) with high oxygen evolution reaction (OER) activity. The effect of alloy composition and GO content on the OER activity was evaluated in the 1 mol L-1 KOH solution. The OER mechanism of the Co0.5Ni0.5/rGO catalyst was disclosed by X-ray photoelectron spectra (XPS) and synchrotron radiation X-ray absorption spectra (XAS). The emulsion containing amphipathic graphene oxide (GO) and hydrophobic nickel/cobalt complexes induces the formation of the carbon-wrapped nanostructure. The coral-like Co0.5Ni0.5/rGO catalyst exhibits the low overpotential of 288 mV at the current density of 10 mA cm-2 and good durability, both of which are superior to the standard RuO2. The synergistic effect between nickel and cobalt effectively regulates the electronic structure and OER activity of the alloy catalysts. Moreover, the interaction between NiCo alloys and carbon shells can reduce the interfacial resistance.