Magnesium alloys are highly susceptible to rapid and non-uniform corrosion in chloride-containing environments. The corrosion process typically evolves from an initially aggressive stage to a relatively stabilized stage during long-term exposure. However, conventional epoxy coatings (EP) and single-stage inhibitor delivery systems cannot effectively adapt to these time-dependent and heterogeneous corrosion conditions, often resulting in premature inhibitor depletion and limited long-term protection. To address this mismatch between corrosion evolution and inhibitor release behavior, a hierarchical porous corrosion inhibitor carrier based on diatomite (DE)-supported sheet-like ZIF-8 loaded with sodium molybdate (Na2MoO4@SZIF-8-DE) was rationally designed and incorporated into an E51 epoxy matrix for the protection of AZ31B magnesium alloy. The in-situ growth of SZIF-8 on the DE surface effectively suppressed MOF agglomeration while constructing a stable hierarchical porous architecture, which enhanced the inhibitor loading efficiency (12.49%) and structural stability. Ultraviolet–visible (UV–Vis) spectroscopy confirmed the pH-responsive and stepwise release behavior of Na2MoO4 from Na2MoO4@SZIF-8-DE, enabling rapid inhibitor release during the early aggressive corrosion stage and sustained release during the subsequent stabilized stage. Electrochemical impedance spectroscopy (EIS) results showed that coatings containing Na2MoO4@SZIF-8-DE/EP exhibited significantly higher low-frequency impedance compared with pure EP coatings. Notably, the coating with 10 wt.% Na2MoO4@SZIF-8-DE/EP maintained the highest impedance after 60 days of immersion in 3.5 wt.% NaCl solution, indicating superior long-term corrosion protection. Moreover, simulation analysis demonstrated enhanced interfacial binding between Na2MoO4@SZIF-8-DE and the AZ31B substrate, which facilitated the formation of a dense and stable protective interface.
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Open Access
Research Article
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Open Access
Review
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This article reviews recent engineering modifications and improvement methods that make natural diatomite an excellent, environmentally friendly catalyst for environmental protection and energy applications. In terms of regulation of the pore structure and surface properties for enhancing catalytic performance and expanding applications. Through physical alteration, chemical alteration or both types of modification on diatomite to make it actived and generate accessibile porosity and numerous active sites, thus enhancing its catalytic performance. Furthermore, at the same time as having adsorption and catalytic activity for pollutant conversion during pollution treatment by concentrating/degradating efficiency may rise. Recent studies show that such a connection can enhance pollutant adsorption efficiency simultaneously in gas-liquid and liquid-solid systems substantially. Representative cases of catalytic treatments: volatile organic compounds (VOCs), antibiotics residues, and heavy metal ions. Diatomite not only provides support but can also act as a mediator during the reaction process to enhance the reaction rate constants even more significantly. There is still difficulty in strictly controlling the microstructure to maintain a stable environment for active sites at different times and clarify interface reactions mechanisms. In the future, more research will be conducted on Diatomite-based materials for photocatalysis, advanced oxidation processes and energy conversion technologies.
Open Access
Mini Review
Issue
As the core functional unit of the flow battery system, the surface and interface microenvironment of carbon electrode materials determine the electrochemical polarization behavior and energy storage performance. From the perspectives of microstructural regulation and electronic structure modulation, this review systematically examines carbon electrode surface/interface modification strategies and their mechanisms for enhancing flow battery performance. It systematically discusses how microstructural regulation and electronic structure modulation can effectively optimize mass transport kinetics, charge transfer efficiency, and electrocatalytic activity, consequently mitigating electrode polarization. Particular emphasis is placed on unveiling the underlying structure–performance relationships and the structure–function interplay between the electrode microenvironments and their resultant electrochemical properties. Furthermore, advanced characterization techniques, including synchrotron radiation, X-ray absorption spectroscopy, in situ Raman spectroscopy, and first-principles calculations, are summarized to elucidate the dynamic evolution of carbon electrodes. These methods provide crucial insights into how surface chemical modifications reconstruct electronic structures and active sites, leading to suppressed concentration and electrochemical polarization. Building on recent progress in atomically dispersed metal electrocatalysts, we also propose the rational design of single-atom catalyst-modified carbon electrodes. Moreover, synergistic strategies integrating high-throughput computation with machine learning are envisioned to establish multidimensional predictive models based on band structure, adsorption energy, and reaction pathways, thereby addressing the bottlenecks of metal utilization efficiency and structure–performance correlation. Overall, this review delivers a multidimensional theoretical framework and technological roadmap for the rational design and practical deployment of high-performance carbon electrodes in next-generation flow batteries.
Open Access
Research Article
Issue
The oxygen reduction reaction (ORR) critical for electrochemical energy conversion systems suffers from sluggish kinetics and high overpotentials that hinder the efficiency of these technologies. Herein, a curvature-dominated microenvironment modulation strategy is demonstrated to enhance ORR performance via engineering a helical hollow carbon nanotube with embedded sub-nanometer tungsten nitride (W2N) clusters. This architecture yields optimized electrostatic field distributions and reduced d-band center of W2N, thereby promoting the enrichment of OH−, the adsorption of oxygen, and the desorption of oxygen intermediates (
Open Access
Review
Issue
Graphene aerogels (GAs) exhibit exceptional potential in energy storage, particularly for high-capacity supercapacitors (SCs), owing to their unique three-dimensional (3D) porous structure, high conductivity, and mechanical stability. Despite limitations in electron transport and surface polarity, their performance can be enhanced through structural optimization and synthesis strategies. This review traces the evolution of GAs from 1931 to 2024, integrating historical development with recent breakthroughs. It analyzes the synergistic effects of synthesis methods (self-assembly, template-assisted) and drying techniques (freezing/supercritical/ambient-pressure drying), elucidating structure–performance relationships and electrochemical mechanisms. This review also details the current research status of GAs applied in double-layer capacitors and pseudocapacitors. It identifies existing issues and summarizes ways to improve performance. Additionally, the research prospects of AI-assisted and in situ dynamic characterization in the development of GAs are outlined. In conclusion, this review aims to further advance high-performance GA electrode materials for SC applications and to anticipate future technological trends, providing a basis and academic reference for researchers in the energy storage field.
Open Access
Research Article
Issue
Nowadays, with the dramatic development of microwave absorbing materials (MAMs), broadband and lightweight are still a topic that cannot be bypassed. Considering the drawbacks of single-component materials and the necessity of magnetic–electric synergistic effect. A novel porous carbon-based aerogel composite with a three-dimensional (3D) biological template is prepared by using rational impedance matching design and multifunctional optimization. Specifically, the coupling of porous materials as well as the synergy of multilevel carbon materials. A novel aerogel of NiCo layered double hydroxide (LDH)/C@Diatomite (De) was prepared by thermal carbonization to convert polypyrrole (PPy) into C particles deposited on the surface of magnetic LDH, coupled to form an aerogel on the basis of De carrier. The influence of the involvement of multilevel carbon on the electromagnetic wave absorption (EMWA) properties of the composites and its potential attenuation mechanism as well as the synergistic effect of the coupling of porous materials are revealed. As a result, the effective absorption bandwidth (EAB) is 8.56 GHz with a reflection loss minimum (RLmin) of −46.85 dB at a thickness of 2.7 mm. With super hydrophobicity and thermal management properties. This work not only provides inspiration for the development of new aerogel MAMs with superior performance, but also has great potential for further development and practical application.
Open Access
Review Article
Issue
Single-atom catalysts (SACs) are considered as the most promising nonprecious metal alternatives for oxygen reduction reactions (ORR) in proton exchange membrane fuel cells because of their high atomic utilization and excellent catalytic performance. However, the inadequate activity and long-term stability of SACs under operational conditions significantly hinder their practical application. Therefore, this paper focuses on understanding the micro- and electronic structures that synergistically enable the activity and stability of oxygen reduction. It provides a comprehensive summary of the effects for improving the ORR catalytic activity and stability of SACs from a multilevel, multi-angle perspective, including macroscale adjustments to the overall catalyst structure, nanoscale optimization of the catalyst microstructure, and atomic-scale regulation of the active sites. Additionally, it emphasizes the importance of advanced simulation, computational methods, and characterization techniques in understanding the catalytic and degradation mechanisms of SACs during the ORR process. This review aims to provide a theoretical foundation for the synergistic catalytic mechanisms and long-term stable operation of catalytic sites in complex heterogeneous environments, thereby advancing research on low-cost, high-efficiency, and highly stable single-atom catalysts.
Open Access
Review
Issue
The application of Mg-based electrochemical energy storage materials in high performance supercapacitors is an essential step to promote the exploitation and utilization of magnesium resources in the field of energy storage. Unfortunately, the inherent chemical properties of magnesium lead to poor cycling stability and electrochemical reactivity, which seriously limit the application of Mg-based materials in supercapacitors. Herein, in this review, more than 70 research papers published in recent 10 years were collected and analyzed. Some representative research works were selected, and the results of various regulative strategies to improve the electrochemical performance of Mg-based materials were discussed. The effects of various regulative strategies (such as constructing nanostructures, synthesizing composites, defect engineering, and binder-free synthesis, etc.) on the electrochemical performance and their mechanism are demonstrated using spinel-structured MgX2O4 and layered structured Mg-X-LDHs as examples. In addition, the application of magnesium oxide and magnesium hydroxide in electrode materials, MXene's solid spacers and hard templates are introduced. Finally, the challenges and outlooks of Mg-based electrochemical energy storage materials in high performance supercapacitors are also discussed.
Open Access
Editorial
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Open Access
Research Article
Issue
Since the discovery of mesoporous silica in 1990s, there have been numerous mesoporous silica-based nanomaterials developed for catalytic applications, aiming at enhanced catalytic activity and stability. Recently, there have also been considerable interests in endowing them with hierarchical porosities to overcome the diffusional limitation for those with long unimodal channels. Present processes of making mesoporous silica largely rely on chemical sources which are relatively expensive and impose environmental concerns on their processes. In this regard, it is desirable to develop hierarchical silica supports from natural minerals. Herein, we present a series of work on surface reconstruction, modification, and functionalization to produce diatomite-based catalysts with original morphology and macro-meso-micro porosities and to test their suitability as catalyst supports for both liquid- and gas-phase reactions. Two wet-chemical routes were developed to introduce mesoporosity to both amorphous and crystalline diatomites. Importantly, we have used computational modeling to affirm that the diatomite morphology can improve catalytic performance based on fluid dynamics simulations. Thus, one could obtain this type of catalysts from numerous natural diatoms that have inherently intricate morphologies and shapes in micrometer scale. In principle, such catalytic nanocomposites acting as miniaturized industrial catalysts could be employed in microfluidic reactors for process intensification.
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