Rapid development of the fifth-generation wireless communication technology (5G) has made electromagnetic interference (EMI) a critical threat to electronic operations and human health. To mitigate severe secondary scattering caused by impedance mismatch in traditional materials, this study proposes a chitosan-assisted self-assembly strategy for two-dimensional (2D) materials. Using directional freezing and freeze-drying, MXene@1T-MoS₂/chitosan composite aerogels with a lamellar porous structure were successfully fabricated. The regulatory effects of chitosan viscosity on microscopic morphology, conductive network construction, and shielding performance were systematically investigated. Results show that medium-viscosity chitosan induces an optimal layered skeleton, enabling sufficient multiple reflection losses within the aerogel. To further enhance absorption-dominated shielding, metallic 1T-MoS₂ was introduced to construct heterointerfaces. Characterization and electromagnetic analysis confirm that the synergy between 1T-MoS₂, MXene, and the chitosan matrix significantly enhances interfacial and dipole polarization losses. Experimental results indicate that the composite aerogels exhibit excellent EMI shielding performance in the X-band, with the absorption coefficient increasing by 0.14 after the introduction of 1T-MoS₂. Furthermore, far-field simulations reveal that the optimized aerogels achieve a remarkable radar cross-section (RCS) reduction, consistently maintaining scattered signal intensities below -20 dB·m² across a wide angular range. Mechanism analysis reveals that the high shielding efficiency stems from the organic synergy of conductive loss, multi-component-induced polarization loss, and multiple reflection effects triggered by the lamellar porous structure. This study successfully achieves a fundamental shift in the shielding mechanism from interfacial reflection to high-efficiency absorption, providing a new experimental basis and design strategy for developing lightweight, high-absorption EMI shielding materials.

The hydrogen evolution reaction (HER) in electrochemical water splitting is crucial for green hydrogen production, yet its efficiency is limited by bubble dynamics at the electrode surface. Accumulated bubbles can block active sites, hinder mass transport, and increase local resistance, causing energy loss. Thus, precise bubble monitoring is crucial for understanding performance limitations and optimizing catalyst design. Conventional bubble monitoring techniques, such as optical microscopy, high-speed imaging, and electrochemical impedance, are constrained by real-time accuracy, complex post-processing, or signal interference at high current densities. Here, we present an in situ fiber optic sensing system that enables precise, real-time monitoring of bubble dynamics during HER. Unlike traditional methods, this system leverages the sensitivity and real-time capability of fiber optic sensors to quantify key parameters, such as growth rate, detachment rate, intake/output ratio, and detaching size. Its reliability and adaptability were validated using two different Pt/C-loaded carbon paper catalysts with distinct catalytic properties. Notably, the system also achieves a bubble detection limit of 79 μm, which meets the spatial resolution requirements for monitoring bubble dynamics relevant to electrocatalytic activity in HER. This sensing platform establishes a practical framework for connecting interfacial gas evolution to electrochemical performance, offering valuable insight for optimizing HER efficiency through catalyst design.

The rational design of high-performance catalysts is crucial for advancing energy conversion and storage technologies. Single-atom and nanoparticle synergistic catalysts (SAC-NPs) have garnered significant attention due to their ability to precisely modulate electronic structures and optimize intermediate adsorption energies. SACs exhibit maximized atomic utilization and well-defined active sites; however, their restricted electronic tunability and inherent instability limit their widespread application. Conversely, NPs provide superior charge transfer capabilities and enhanced catalytic stability, effectively complementing SACs. The SAC-NPs leverage atomic-scale electronic interactions to enhance catalytic activity, stability, and reaction kinetics, making it a promising platform for electrocatalysis. Therefore, elucidating the synergistic catalytic mechanisms of SAC-NPs and refining optimization strategies are crucial for advancing the development of high-performance catalysts. This review systematically summarizes the synthesis strategies and structural modulation approaches of SAC-NPs. Furthermore, the synergistic catalytic mechanisms, encompassing electron transfer, tandem catalysis, and bifunctional catalysis, are critically examined from both experimental and theoretical perspectives. Finally, recent advancements in SAC-NPs for key electrocatalytic reactions are reviewed, along with current challenges and future research directions. This work aims to provide comprehensive theoretical and practical guidance for the development of SAC-NPs, facilitating the rational design of next-generation catalysts and advancing renewable energy technologies.

Environmental pollution and global warming caused by fossil fuels have become increasingly serious issues. Therefore, it is urgent to explore novel strategies to obtain sustainable, renewable and clean energy. Fortunately, ambient energy harvesting technologies, which are receiving increasing attention, provide an optimal solution. Additionally, the investigation of two-dimensional (2D) materials represented by transition metal dichalcogenides (TMDs) significantly facilitates the advancement of ambient energy harvesting technologies due to their unique properties, enabling the application of ambient energy harvesting. Herein, we summarized recent advances in the application of TMDs in thermal energy harvesting, osmotic energy harvesting, mechanical energy harvesting, water energy harvesting and radiofrequency energy harvesting respectively. In the meanwhile, we listed some representative structure and device optimization strategies for enhancing the energy conversion performance of these ambient energy harvesters, aiming to provide valuable insights for future investigations towards further optimization. Finally, we highlight the pressing issues currently faced in the application of the TMDs ambient energy harvesting technologies and propose some potential solutions to these challenges. We aimed to provide a comprehensive review in the applications of the energy harvesting technologies, in order to provide innovative insights for optimizing existing TMDs-based technologies.

Precise design and synthesis of sub-nano scale catalysts with controllable electronic and geometric structures are pivotal for enhancing the hydrogen evolution reaction (HER) performance of molybdenum sulfide (MoS₂) and unraveling its structure−activity relationship. By leveraging transition molybdenum polysulfide clusters as functional units for multi-level ordering, we successfully designed and synthesized MoS_x nanowire networks derived from [Mo₃S₁₃]²⁻ clusters via evaporation-induced self-assembly, which exhibit enhanced HER activity attributed to a high density of active sites and dynamic evolution behavior under cathodic potentials. MoS_x nanowire networks electrode yields a current density of 100 mA·cm⁻² at 142 mV in 0.5 M H₂SO₄. This work provides an attractive prospect for optimizing catalysts at the sub-nano scale and offers insights into a strategy for designing catalysts in various gas evolution reactions.

The transition metal chalcogenides represented by MoS₂ are the ideal choice for non-precious metal-based hydrogen evolution catalysts. However, whether in acidic or alkaline environments, the catalytic activity of pure MoS₂ is still difficult to compete with Pt. Recent studies have shown that the electronic structure of materials can be adjusted by constructing lattice-matched heterojunctions, thus optimizing the adsorption free energy of intermediates in the catalytic hydrogen production process of materials, so as to effectively improve the electrocatalytic hydrogen production activity of catalysts. However, it is still a great challenge to prepare heterojunctions with lattice-matched structures as efficient electrocatalytic hydrogen production catalysts. Herein, we developed a one-step hydrothermal method to construct Ni-MoS₂@NiS₂@Ni₃S₂ (Ni-MoS₂ on behalf of Ni doping MoS₂) electrocatalyst with multiple heterogeneous interfaces which possesses rich catalytic reaction sites. The Ni-MoS₂@NiS₂@Ni₃S₂ electrocatalyst produced an extremely low overpotential of 69.4 mV with 10 mA·cm⁻² current density for hydrogen evolution reaction (HER) in 1.0 M KOH. This work provides valuable enlightenment for exploring the mechanism of HER enhancement to optimize the surface electronic structure of MoS₂, and provides an effective idea for constructing rare metal catalysts in HER and other fields.

Doping foreign metal atoms into the substrate of transition metal dichalcogenides (TMDs) enables the formation of diverse atomic structure configurations, including isolated atoms, chains, and clusters. Therefore, it is very important to reasonably control the atomic structure and determine the structure–activity relationship between the atomic configurations and the hydrogen evolution reaction (HER) performance. Although numerous studies have indicated that doping can yield diverse atomic structure configurations, there remains an incomplete understanding of the relationship between atomic configurations within the lattice of TMDs and their performance. Here, diverse atomic structure configurations of adsorptive doping, substitutional doping, and TMDs alloys are summarized. The structure–activity relationship between different atomic configurations and HER performance can be determined by micro-nanostructure devices and density functional theory (DFT) calculations. These diverse atomic structure configurations are of great significance for activating the inert basal plane of TMDs and improving the catalytic activity of HER. Finally, we have summarized the current challenges and future opportunities, offering new perspectives for the design of highly active and stable metal-doped TMDs catalysts.

The weak van der Waals gap endows two dimensional transition metal dichalcogenides (2D TMDs) with the potential to realize guest intercalation and host exfoliation. Intriguingly, the liquid intercalation and exfoliation is a facile, low-cost, versatile and scalable strategy to modulate the structure and physiochemical property of TMDs via introducing foreign species into interlayer. In this review, firstly, we briefly introduce the resultant hybrid superlattice and disperse nanosheets with tailored properties fabricated via liquid intercalation and exfoliation. Subsequently, we systematically analyze the intercalation phenomenon and limitations of various intercalants in chemical or electrochemical methods. Afterwards, we intensely discuss diverse functionalities of resultant materials, focusing on their potential applications in energy conversion, energy storage, water purification, electronics, thermoelectrics and superconductor. Finally, we highlight the challenges and outlooks for precise and mass production of 2D TMDs-based materials via liquid intercalation and exfoliation. This review enriches the overview of liquid intercalation and exfoliation strategy, and paves the path for relevant high-performance devices.

Amorphous materials are one kind of nonequilibrium materials and have become one of the most active research fields. Compared with crystalline solids, the theory of amorphous materials is still in infancy because their characteristic of atomic arrangement is more like liquid and has no long-range periodicity. Recently, as the representative of amorphous materials, amorphous molybdenum sulfide (a-MoS_x) with unique physical and chemical properties has been studied extensively. However, considerable debate surrounds the structure–property relationships of a-MoS_x owing to its diverse Mo-S motifs. Herein, we summarize recent discoveries and research results regarding a-MoS_x, whose structural characteristics, synthetic strategies, formation criteria, and comprehensive applications are discussed in detail. Finally, this review is ended with our personal insights and critical outlooks over the development of a-MoS_x.

Heteroatom doping is a promising approach to enhance catalytic activity by modulating physical properties, electronic structure, and reaction pathway. Herein, we demonstrate that appropriate Ni-doping could trigger a preferential transition of the basal plane from 2H (trigonal prismatic) to 1T′ (clustered Mo) by inducing lattice distortion and S vacancy (SV) and thus dramatically facilitate its catalytic hydrogen evolution activity. It is noteworthy that the unique catalysts did possess superior catalytic performance of hydrogen evolution reaction (HER). The rate of photocatalytic hydrogen evolution could reach 20.45 mmol·g⁻¹·h⁻¹ and reduced only slightly in the long period of the photocatalytic process. First-principles calculations reveal that the distorted Ni-1T′-MoS₂ with SV could generate favorable water adsorption energy (E_ad(H₂O)) and Gibbs free energy of hydrogen adsorption (∆G_H). This work exhibits a facile and promising pathway for synergistically regulating physical properties, electronic structure, or wettability based on the doping strategy for designing HER electrocatalysts.