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Prussian blue analogue (PBA)/metal-organic frameworks (MOFs) are multifunctional precursors for the synthesis of metal/metal compounds, carbon, and their derived composites (P/MDCs) in chemical, medical, energy, and other applications. P/MDCs combine the advantages of both the high specific surface area of PBA/MOF and the electronic conductivity of metal compound/carbon. Although the calcination under different atmospheres has been extensively studied, the transformation mechanism of PBA/MOF under hydrothermal conditions remains unclear. The qualitative preparation of P/MDCs in hydrothermal conditions remains a challenge. Here, we select PBA to construct a machine-learning model and measure its hydrothermal phase diagram. The architecture-activity relationship of substances among nine parameters was analyzed for the hydrothermal phase transformation of PBA. Excitingly, we established a universal qualitative model to accurately fabricate 31 PBA derivates. Additionally, we performed three-dimensional reconstructed transmission electron microscopy, X-ray absorption fine structure spectroscopy, ultraviolet photoelectron spectroscopy, in situ X-ray powder diffraction, and theoretical calculation to analyze the advantages of hydrothermal derivatives in the oxygen evolution reaction and clarify their reaction mechanisms. We uncover the unified principles of the hydrothermal phase transformation of PBA, and we expect to guide the design for a wide range of composites.
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Heterostructured materials commonly consist of bifunctions due to the different ingredients. For host material in the sulfur cathode of lithium-sulfur (Li-S) batteries, the chemical adsorption and catalytic activity for lithium polysulfides (LiPS) are important. This work obtains a Ni5P2-Ni nanoparticle (Ni5P2-NiNPs) heterostructure through a confined self-reduction method followed by an in situ phosphorization process using Al/Ni-MOF as precursors. The Ni5P2-Ni heterostructure not only has strong chemical adsorption, but also can effectively catalyze LiPS conversion. Furthermore, the synthetic route can keep Ni5P2-NiNPs inside of the nanocomposites, which have structural stability, high conductivity, and efficient adsorption/catalysis in LiPS conversion. These advantages make the assembled Li-S battery deliver a reversible specific capacity of 619.7 mAh g- 1 at 0.5 C after 200 cycles. The in situ ultraviolet-visible technique proves the catalytic effect of Ni5P2-Ni heterostructure on LiPS conversion during the discharge process.
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Stretchable strain sensors play a crucial role in intelligent wearable systems, serving as the interface between humans and environment by translating mechanical strains into electrical signals. Traditional fiber strain sensors with intrinsic uniform axial strain distribution face challenges in achieving high sensitivity and anisotropy. Moreover, existing micro/nano-structure designs often compromise stretchability and durability. To address these challenges, a novel approach of using 3D printing to fabricate MXene-based flexible sensors with tunable micro and macrostructures. Poly(tetrafluoroethylene) (PTFE) as a pore-inducing agent is added into 3D printable inks to achieve controllable microstructural modifications. In addition to microstructure tuning, 3D printing is employed for macrostructural design modifications, guided by finite element modeling (FEM) simulations. As a result, the 3D printed sensors exhibit heightened sensitivity and anisotropy, making them suitable for tracking static and dynamic displacement changes. The proposed approach presents an efficient and economically viable solution for standardized large-scale production of advanced wire strain sensors.
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Rationally and precisely tuning the composition and structure of materials is a viable strategy to improve electrochemical deionization (EDI) performances, which yet faces enormous challenges. Herein, an eco-friendly biomimetic mineralization synthetic strategy is developed to synthesize the flower-like cobalt selenide/reduced graphene oxide (Bio-CoSe2/rGO) composites and used as advanced sodium ion adsorption electrodes. Benefiting from the slow and controllable reaction kinetics provided by the biomimetic mineralization process, the flower-like CoSe2 is uniformly constructed in the rGO, which is endowed with robust architecture, substantial adsorption sites and rapid charge/ion transport. The Bio-CoSe2/rGO electrode yields the maximum salt adsorption capacity and salt adsorption rate of 56.3 mg g-1 and 5.6 mg g-1 min-1 respectively, and 92.5% capacity retention after 60 cycles. These results overmatch the pristine CoSe2 and irregular granular CoSe2/rGO synthesized by a hydrothermal method, proving the structural superiority of the Bio-CoSe2/rGO composites. Furthermore, the in-depth adsorption kinetics study indicates the chemisorption nature of sodium ion adsorption. The structures of the Bio-CoSe2/rGO composites after long term EDI cycles are intensively studied to unveil the mechanism behind such superior EDI performances. This study offers one effective method for constructing advanced EDI electrodes, and enriches the application of the biomimetic mineralization synthetic strategy.
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Glucose holds significant importance in disease diagnosis as well as beverage quality monitoring. The high-efficiency electrochemical sensor plays a crucial role in the electrochemical conversion technology. Ni(OH)2 nanosheets are provided with high specific surface area and redox activity that are widely used in electrochemistry. Conductive metal-organic frameworks (cMOFs) perfectly combine the structural controllability of organic materials with the long-range ordering of inorganic materials that possess the characteristic of high electron mobility. Based on the above considerations, the combination of Ni(OH)2 and Ni-HHTP (HHTP=2,3,6,7,10,11-hexahydroxytriphenylene) as an electrode modification material is designed to enhance electrochemical performance. In this work, to improve glucose detection, a sequence of Ni(OH)2@NiCo-HHTP and NiM-LDH@Ni-HHTP (M=Co2+, Mn2+, Cu2+, LDH=layered double hydroxide) are successfully synthesised by doping metals into Ni-HHTP and Ni(OH)2, respectively. As a result, NiCu-LDH@Ni-HHTP showed the best excellent glucose detection sensitivity.
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Conductive metal-organic frameworks (cMOFs), as a kind of porous material, are considered to be highly promising materials in the field of electrochemistry due to their excellent conductivity. However, due to the low specific capacitance of pure cMOFs, their application in supercapacitors is limited. By virtue of the high theoretical capacity and excellent chemical stability of Co-based compounds, in this work, cMOFs' M-HHTP (M = Ni, Co, NiCo, HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene) are grown in situ on Co(OH)2, CoP, and Co3O4 nanosheets, resulting in a series of electroactive compounds as electrode materials used in supercapacitors. Among all of the compounds, Ni-HHTP@Co(OH)2 shows the most excellent energy storage performance and outstanding cyclic stability in the application of aqueous asymmetric supercapacitors.
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The weak chemical immobilization ability and poor catalytic effect of MXene inhibit its application in lithium-sulfur (Li-S) batteries. Herein, a novel MXene@FeCoNiP composite is rationally developed and utilized as a sulfur host for Li-S batteries. In this well-designed MXene-based nanostructure, the introduction of FeCoNiP in the interlayer of MXene nanosheets can not only effectively inhibit the restacking of MXene nanosheets but also act as an accelerator for the adsorption and catalysis of polysulfides to restrain the shuttling effect and facilitate the transformation of polysulfides. The existence of two-dimensional MXene nanosheets provides more active sites and improves the conductivity, which is beneficial for accelerating the reaction kinetics. Thus, the as-prepared MXene@FeCoNiP composites achieve an outstanding performance for Li-S batteries. This work provides an opportunity to construct an ideal sulfur host with the triple effect of "conductivity-adsorption-catalysis".
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Designing and synthesizing hollow frame structures with unique three-dimensional open structures in electrocatalysis remain a challenge. Etching is an effective method to synthesize metal-organic frameworks (MOFs) with a hollow structure and rich function. Herein, we report the design and synthesis of Hf-doped CoP hollow nanocubes by selective etching and ion exchange. Different from the traditional etching method, we used acid xylenol orange solution to etch typically the (211) crystal face of ZIF-67, obtaining the unique bell-like structure, named XO-ZIF-67. Subsequently, Hf-doped CoP hollow nanocubes were formed by Hf4+ doping and simple phosphating treatment. Electrochemical tests showed that the overpotential of the obtained catalyst is only 291 mV at the current density of 10 mA cm-2 when applied in catalyzing the oxygen evolution reaction (OER). Furthermore, the catalyst shows excellent stability when running in 1 M KOH solution for 25 h.
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Silica nanoparticles (SiNPs) are widely used in the biomedical field and can enter the central nervous system through the blood-brain barrier, causing damage to hippocampal neurons. However, the specific mechanism remains unclear. In this experiment, HT22 cells were selected as the experimental model in vitro, and the survival rate of cells under the action of SiNPs was detected by MTT method, reactive oxygen species (ROS), lactate dehydrogenase (LDH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and adenosine triphosphate (ATP) were tested by the kit, the ultrastructure of the cells was observed by transmission electron microscope, membrane potential (MMP), calcium ion (Ca2+) and apoptosis rate were measured by flow cytometry, and the expressions of mitochondrial functional protein, mitochondrial dynein, mitochondrial autophagy protein as well as apoptosis related protein were detected by Western blot. The results showed that cell survival rate, SOD, CAT, GSH-Px, ATP and MMP gradually decreased with the increase of SiNPs concentration, while intracellular ROS, Ca2+, LDH and apoptosis rate increased with the increase of SiNPs concentration. In total cellular proteins,the expressions of mitochondrial functional proteins VDAC and UCP2 gradually increased, the expression of mitochondrial dynamic related protein DRP1 increased while the expressions of OPA1 and Mfn2 decreased. The expressions of mitophagy related proteins PINK1, Parkin and LC3â ¡/LC3â increased and P62 gradually decreased, as well as the expressions of apoptosis related proteins Apaf-1, Cleaved-Caspase-3, Caspase-3, Caspase-9, Bax and Cyt-C. In mitochondrial proteins, the expressions of mitochondrial dynamic related proteins DRP1 and p-DRP1 were increased, while the expressions of OPA1 and Mfn2 were decreased. Expressions of mitochondrial autophagy associated proteins PINK1, Parkin, LC3II/LC3I increased, P62 decreased gradually, as well as the expressions of apoptosis related proteins Cleaved-Caspase-3, Caspase-3, and Caspase-9 increased, and Cyt-C expressions decreased. To further demonstrate the role of ROS and DRP1 in HT22 cell apoptosis induced by SiNPs, we selected the ROS inhibitor N-Acetylcysteine (NAC) and Dynamin-related protein 1 (DRP1) inhibitor Mdivi-1. The experimental results indicated that the above effects were remarkably improved after the use of inhibitors, further confirming that SiNPs induce the production of ROS in cells, activate DRP1, cause excessive mitochondrial division, induce mitophagy, destroy mitochondrial function and eventually lead to apoptosis.
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Dinaminas , Mitofagia , Nanopartículas , Dióxido de Silício , Trifosfato de Adenosina , Apoptose , Proteínas Reguladoras de Apoptose/metabolismo , Caspase 3/metabolismo , Caspase 9/metabolismo , Dinaminas/metabolismo , Nanopartículas/toxicidade , Proteínas Quinases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Dióxido de Silício/farmacologia , Superóxido Dismutase/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Camundongos , Linhagem Celular TumoralRESUMO
H9N2 avian influenza poses a significant public health risk, necessitating effective vaccines for mass immunization. Oral inactivated vaccines offer advantages like the ease of administration, but their efficacy often requires enhancement through mucosal adjuvants. In a previous study, we established a novel complex of polysaccharide from Atractylodes macrocephala Koidz binding with zinc oxide nanoparticles (AMP-ZnONPs) and preliminarily demonstrated its immune-enhancing function. This work aimed to evaluate the efficacy of AMP-ZnONPs as adjuvants in an oral H9N2-inactivated vaccine and the vaccine's impact on intestinal mucosal immunity. In this study, mice were orally vaccinated on days 0 and 14 after adapting to the environment. AMP-ZnONPs significantly improved HI titers, the levels of specific IgG, IgG1 and IgG2a in serum and sIgA in intestinal lavage fluid; increased the number of B-1 and B-2 cells and dendritic cell populations; and enhanced the mRNA expression of intestinal homing factors and immune-related cytokines. Interestingly, AMP-ZnONPs were more likely to affect B-1 cells than B-2 cells. AMP-ZnONPs showed mucosal immune enhancement that was comparable to positive control (cholera toxin, CT), but not to the side effect of weight loss caused by CT. Compared to the whole-inactivated H9N2 virus (WIV) group, the WIV + AMP-ZnONP and WIV + CT groups exhibited opposite shifts in gut microbial abundance. AMP-ZnONPs serve as an effective and safe mucosal adjuvant for oral WIV, improving cellular, humoral and mucosal immunity and microbiota in the gastrointestinal tract, avoiding the related undesired effects of CT.
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Atractylodes , Vírus da Influenza A Subtipo H9N2 , Vacinas contra Influenza , Óxido de Zinco , Animais , Camundongos , Adjuvantes Imunológicos/farmacologia , Imunidade nas Mucosas , Vacinas de Produtos Inativados , Polissacarídeos/farmacologia , Anticorpos AntiviraisRESUMO
In this study, we introduce a novel approach for synthesizing two-dimensional (2D) MXene heterostructures featuring a sandwiched and cross-linked network structure. This method addresses the common issue of activity degradation in 2D nanomaterials caused by inevitable aggregation. By utilizing the distinct surface characteristics of MXene, we successfully induced the growth of various 2D nanomaterials on MXene substrates. This strategy effectively mitigates self-stacking defects and augments the exposure of surface areas. In particular, the obtained 2D-2D MXene@NiCo-layered double hydroxide (MH-NiCo) heterostructures exhibit enhanced structural stability, improved chemical reversibility, and heightened charge transfer efficiency, outperforming pure NiCo LDH. The aqueous MH-Ni4Co1//Zn@carbon cloth (MH-Ni4Co1//Zn@CC) battery demonstrates exceptional performance with a remarkable specific capacity of 0.61â mAh cm-2, maintaining 96.6 % capacitance after 2300â cycles. Additionally, it achieves an energy density of 1.047â mWh cm-2 and a power density of 32.899â mW cm-2. This research not only paves the way for new design paradigms in energy-related nanomaterials but also offers invaluable insights for the application and optimization of 2D-2D heterostructures in advanced electrochemical devices.
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Rechargeable aqueous zinc-ion (Zn-ion) batteries are widely regarded as important candidates for next-generation energy storage systems for low-cost renewable energy storage. However, the development of Zn-ion batteries is currently facing significant challenges due to uncontrollable Zn dendrite growth and severe parasitic reactions on Zn metal anodes. Herein, we report an innovative strategy to improve the performance of aqueous Zn-ion batteries by leveraging the self-assembly of bovine serum albumin (BSA) into a bilayer configuration on Zn metal anodes. BSA's hydrophilic and hydrophobic fragments form unique and intelligent ion channels, which regulate the migration of Zn ions and facilitate their desolvation process, significantly diminishing parasitic reactions on Zn anodes and leading to a uniform Zn deposition along the Zn (002) plane. Notably, the Zn||Zn symmetric cell with BSA as the electrolyte additive demonstrated a stable cycling performance for up to 2400 hours at a high current density of 10 mA cm-2. This work demonstrates the pivotal role of self-assembled protein bilayer structures in improving the durability of Zn anodes in aqueous Zn-ion batteries.
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Prussian blue analogues (PBAs) have been widely studied in aqueous zinc-ion batteries (AZIBs) due to the characteristics of large specific surface area, open aperture, and straightforward synthesis. In this work, vanadium-based PBA nanocubes were firstly prepared using a mild in-situ conversion strategy at room temperature without the protection of noble gas. Benefiting from the multiple-redox active sites of V3+/V4+, V4+/V5+ and Fe2+/Fe3+, the cathode exhibited an excellent discharge specific capacity of 200 mA h g-1 in AZIBs, which is much higher than those of other metal-based PBAs nanocubes. To further improve the long-term cycling stability of the V-PBA cathode, a high concentration water-in-salt electrolyte (4.5 M ZnSO4 + 3 M Zn(OTf)2), and a water-based eutectic electrolyte (5.55 M glucose + 3 M Zn(OTf)2) were designed to successfully inhibit the dissolution of vanadium and improve the deposition of Zn2+ onto the zinc anode. More importantly, the assembled AZIBs maintained 55% of their highest discharge specific capacity even after 10000 cycles at 10 A g-1 with superior rate capability. This study provides a new strategy for the preparation of pure PBA nanostructures and a new direction for enhancing the long-term cycling stability of PBA-based AZIBs at high current densities for industrialization prospects.
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Herein, an interfacial electron redistribution is proposed to boost the activity of carbon-supported spinel NiCo2O4 catalyst toward oxygen conversion via Fe, N-doping strategy. Fe-doping into octahedron induces a redistribution of electrons between Co and Ni atoms on NiCo1.8Fe0.2O4@N-carbon. The increased electron density of Co promotes the coordination of water to Co sites and further dissociation. The generation of proton from water improves the overall activity for the oxygen reduction reaction (ORR). The increased electron density of Ni facilitates the generation of oxygen vacancies. The Ni-VO-Fe structure accelerates the deprotonation of *OOH to improve the activity toward oxygen evolution reaction (OER). N-doping modulates the electron density of carbon to form active sites for the adsorption and protonation of oxygen species. Fir wood-derived carbon endows catalyst with an integral structure to enable outstanding electrocatalytic performance. The NiCo1.8Fe0.2O4@N-carbon express high half-wave potential up to 0.86â V in ORR and low overpotential of 270â mV at 10â mA cm-2 in OER. The zinc-air batteries (ZABs) assembled with the as-prepared catalyst achieve long-term cycle stability (over 2000â cycles) with peak power density (180â mWcm-2). Fe, N-doping strategy drives the catalysis of biomass-derived carbon-based catalysts to the highest level for the oxygen conversion in ZABs.
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The design of three-dimensional covalent organic frameworks (3D COFs) using linear and trigonal linkers remains challenging due to the difficulty in achieving a specific non-planar spatial arrangement with low-connectivity building units. Here, we report the novel 3D COFs with linear and trigonal linkers, termed TMB-COFs, exhibiting srs topology. The steric hindrance provides an additional force to alter the torsion angles of peripheral triangular units, guiding the linear unit to connect with the trigonal unit into 3D srs frameworks, rather than the more commonly observed two-dimensional (2D) hcb structures. Furthermore, we comprehensively examined the hydrogen peroxide photocatalytic production capacity of the TMB-COFs in comparison with analogous 2D COFs. The experimental results and DFT calculations demonstrate a significant enhancement in photocatalytic hydrogen peroxide production efficacy through framework regulation. This work emphasizes the steric configuration using low connectivity building units, offering a fresh perspective on the design and application of 3D COFs.
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The extensive industrial applications of fuel oil, a critical strategic resource, are accompanied by significant environmental and health concerns due to the presence of sulfur-containing compounds in its composition, which result in hazardous combustion waste. Extensive research has been conducted to develop technologies for low-vulcanization fuel production to address this issue. Consequently, the investigation of catalysts for environmentally friendly and safe photocatalytic desulfurization becomes imperative. To that end, we have designed efficient MIL-101(Fe)/CQDs@g-C3N4 (MIL101/CDs-C3N4) Z-scheme heterojunction photocatalysts with high carrier separation and mobility through a thermal polymerization-hydrothermal strategy. The high concentration of photogenerated carriers facilitates the activation of oxygen and H2O2, leading to increased production of ROS (â O2 -, â OH, h+), thereby enhancing the photocatalytic desulfurization (PODS). Additionally, DFT (Density functional theory) calculations were utilized to determine the electron migration pathways of the catalysts and adsorption energies of DBT (dibenzothiophene). Moreover, Gibbs free energy calculations indicated that MIL101/CDs-C3N4 exhibited the lowest activation energy for oxygen and H2O2. The mechanism of photocatalytic desulfurization was proposed through a combination of theoretical calculations and experimental studies. This study provides guidance for the development of MOF-based Z-scheme systems and their practical application in desulfurization processes.
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Metal-organic frameworks (MOFs) are considered as a promising candidate for advancing energy storage owing to their intrinsic multi-channel architecture, high theoretical capacity, and precise adjustability. However, the low conductivity and poor structural stability lead to unsatisfactory rate and cycling performance, greatly hindering their practical application. Herein, we propose a sea urchin-like Co-ZIF-L superstructure using molecular template to induce self-assembly followed by ion exchange method, which shows improved conductivity, successive channels, and high stability. The ion exchange can gradually etch the superstructure, leading to the reconstruction of Co-ZIF-L with three-dimensional (3D) cross-linked ultrathin porous nanosheets. Moreover, the precise control of Co to Ni ratios can construct effective micro-electric field and synergistically enhance the rapid transfer of electrons and electrolyte ions, improving the conductivity and stability of CoNi-ZIF-L. The Co6.53Ni-ZIF-L electrode exhibits a high specific capacity (602â F g-1 at 1â A g-1) and long cycling stability (95.3 % retention after 4,000 cycles at 5â A g-1). The Co6.53Ni-ZIF-L//AC asymmetric flexible supercapacitor employing gel electrolyte also exhibits excellent cycling stability (93.3 % retention after 4000 cycles at 5â A g-1). This discovery provides valuable insights for electrode material selection and energy storage efficiency improvement.
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The remarkable flexibility and heightened sensitivity of flexible sensors have drawn significant attention, setting them apart from traditional sensor technology. Within this domain, hydrogels-3D crosslinked networks of hydrophilic polymers-emerge as a leading material for the new generation of flexible sensors, thanks to their unique material properties. These include structural versatility, which imparts traits like adhesiveness and self-healing capabilities. Traditional templating-based methods fall short of tailor-made applications in crafting flexible sensors. In contrast, 3D printing technology stands out with its superior fabrication precision, cost-effectiveness, and satisfactory production efficiency, making it a more suitable approach than templating-based strategies. This review spotlights the latest hydrogel-based flexible sensors developed through 3D printing. It begins by categorizing hydrogels and outlining various 3D-printing techniques. It then focuses on a range of flexible sensors-including those for strain, pressure, pH, temperature, and biosensors-detailing their fabrication methods and applications. Furthermore, it explores the sensing mechanisms and concludes with an analysis of existing challenges and prospects for future research breakthroughs in this field.
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Lithium-sulfur batteries (LSBs) have emerged as a promising energy storage system, but their practical application is hindered by the polysulfide shuttle effect and sluggish redox kinetics. To address these challenges, we have developed CoO/MoO3@nitrogen-doped carbon (CoO/MoO3@NC) hollow heterostructures based on porous ZIF-67 as separators in LSBs. CoO has a strong anchoring effect on polysulfides. The heterostructure formed after the introduction of MoO3 increases the adsorption of polysulfides. The carbon coating outside the heterostructure improves the ion transmission efficiency of the battery, leading to enhanced electrochemical performance. The modified LSB demonstrates a low-capacity decay rate of 0.092% over 500 cycles at 0.5C, with a high discharge capacity of 613 mAh g-1 at 1C. This work presents a novel approach for the preparation of hollow heterostructure materials, aiming for high-performance LSBs.
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Manganese-based compounds, especially manganese oxides, are one of the most exceptional electrode materials. Specifically, manganese oxides have gained significant interest owing to their unique crystal structures, high theoretical capacity, abundant natural availability and eco-friendly nature. However, as transition metal semiconductors, manganese oxide possess low electrical conductivity, limited rate capacity, and suboptical cycle stability. Thus, combining manganese oxides with carbon or other metallic materials can significantly improve their electrochemical performance. These composites increase active sites and conductivity, thereby improving electrode reaction kinetics, cycle stability, and lifespan of supercapacitors (SCs) and batteries. This paper reviews the latest applications of Mn-based cathodes in SCs and advanced batteries. Moreover, the energy storage mechanisms were also proposed. In this review, the development prospects and challenges for advanced energy storage applications of Mn-based cathodes are summarized.