Photoassisted Electrochemical Hydrogen Evolution Reaction of MFe2O4@Ultrathin Black Phosphorus Amorphous-Crystalline Interface

Amorphous/Crystalline Heterostructured Nanomaterials: An Emerging Platform for Electrochemical Energy Storage

With the expanding adoption of large-scale energy storage systems and electrical devices, batteries and supercapacitors are encountering growing demands and challenges related to their energy storage capability. Amorphous/crystalline heterostructured nanomaterials (AC-HNMs) have emerged as promising electrode materials to address these needs. AC-HNMs leverage synergistic interactions between their amorphous and crystalline phases, along with abundant interface effects, which enhance capacity output and accelerate mass and charge transfer dynamics in electrochemical energy storage (EES) devices. Motivated by these elements, this review provides a comprehensive overview of synthesis strategies and advanced EES applications explored in current research on AC-HNMs. It begins with a summary of various synthesis strategies of AC-HNMs. Diverse EES devices of AC-HNMs, such as metal-ion batteries, metal-air batteries, lithium-sulfur batteries, and supercapacitors, are thoroughly elucidated, with particular focus on the underlying structure-activity relationship among amorphous/crystalline heterostructure, electrochemical performance, and mechanism. Finally, challenges and perspectives for AC-HNMs are proposed to offer insights that may guide their continued development and optimization.

AgNWs/Fe3O4@NC Conductive Network Hierarchical Assembly to Prepare Flexible EMI Shielding Textile

With the rapid development of high-power electronic instruments and communication technology, efficient electromagnetic shielding materials with strong absorption of electromagnetic waves and low reflection characteristics have become the focus of the world's attention. This study designs and synthesizes N-doped carbon-coated hollow Fe3O4 nanospheres (Fe3O4@NC) by spraying Ag nanowires (AgNWs) on textiles as conductive networks. Because of the high permeability and hollow structure Fe3O4@NC, electromagnetic wave goes through a unique process of "absorption, reflection, and reabsorption" when it passes through the surface of the composite textile. In X-band (≈8.2-12.4 GHz), the average electromagnetic interference shielding effectiveness (EMI SE) reaches 50.1 dB, while the reflectance shielding efficiency (SER) is only 2.6 dB, and the average reflectance power coefficient (R) is as low as 0.45. The composite fabric has excellent properties and provides an effective strategy for electromagnetic interference shielding based on absorption.

Ni3S2/Co9S8 embedded poor crystallinity NiCo layered double hydroxides hierarchical nanostructures for efficient overall water splitting

Nickel-cobalt bimetallic layered double hydroxides (NiCo LDHs) are potential electrocatalysts with high performance and stability for overall water-splitting. However, its weak conductivity limits its practical applications. Herein, a simple hydrothermal in-situ conversion strategy is employed for constructing the novel heterogeneous electrocatalyst of Ni₃S₂/Co₉S₈ embedded poor crystallinity (Pc) NiCo LDH nanosheet arrays grown on the Ni foam (Pc-NiCo LDH/ Ni₃S₂/Co₉S₈), which can improve the conductivity via regulating the crystallinity. The crystallinity of NiCo LDH is well regulated by adjusting the amount of sulfur source, and the construction of Ni₃S₂/Co₉S₈ heterostructure exposes more active sites, improves the electrical conductivity, enhances the electronic interaction between NiCo LDH and Ni₃S₂/Co₉S₈, and significantly promotes the kinetics of water splitting. The optimized Pc-NiCo LDH/Ni₃S₂/Co₉S₈ hierarchical structure as both the anode and cathode exhibit the overall water splitting performance with the cell voltage of only 1.744 V to achieve the current density of 50 mA cm^-2 in the alkaline media and shows the competitive H₂ and O₂ production rate of 6.4 and 3.1 μL s^-1, respectively, suggesting its potential practical applications. This work provides a novel idea for the design of multiphase composite electrocatalysts applied in water splitting.

Sea urchin-like amorphous MgNiCo mixed metal hydroxide nanoarrays for efficient overall water splitting under industrial electrolytic conditions

Exploring amorphous mixed transition metal hydroxide electrocatalysts with high performance and stability for overall water splitting is a difficult challenge under industrial electrolytic conditions. Herein, a sea urchin-like amorphous MgNiCo hydroxide (Mg_xNi_1-xCo-OH, 0 < x < 1), self-assembled from nanowire arrays, is synthesized by the hydrothermal process. The synergistic effect between Mg and Ni/Co adjusts their crystal structure and morphology, which can improve the inherent activity and provide more active sites. Benefiting from the favorable structural features, Mg_0.5Ni_0.5Co-OH exhibits superior electrocatalytic oxygen and hydrogen evolution reaction (OER and HER) activity with a low overpotential of 277 and 110 mV (10 mA cm^-2) in 1 M KOH at 25 °C. Furthermore, overpotentials of 239 and 197 mV are required to achieve a current density of 50 mA cm^-2 for the OER and HER under simulated industrial electrolysis conditions (5 M KOH at 65 °C). Notably, Mg_0.5Ni_0.5Co-OH remarkably accelerates water splitting with a low voltage of 1.938 and 1.699 V for 50 mA cm^-2 in 1 M KOH at 25 °C and 5 M KOH at 65 °C, respectively. This work presents a novel amorphous strategy to design and construct sea urchin-like mixed metal hydroxide bifunctional efficient electrocatalysts for industrial applications.