Lamellar Stacks Research Articles

Synergistic Contribution of Oligo(ethylene glycol) and Fluorine Substitution of Conjugated Polymer Photocatalysts toward Solar Driven Sacrificial Hydrogen Evolution.

To separately explore the importance of hydrophilicity and backbone planarity of polymer photocatalyst, a series of benzothiadiazole-based donor-acceptor alternating copolymers incorporating alkoxy, linear oligo(ethylene glycol) (OEG) side chain, and backbone fluorine substituents is presented. The OEG side chains in the polymer backbone increase the surface energy of the polymer nanoparticles, thereby improving the interaction with water and facilitating electron transfer to water. Moreover, the OEG-attached copolymers exhibit enhanced intermolecular packing compared to polymers with alkoxy side chains, which is possibly attributed to the self-assembly properties of the side chains. Fluorine substituents on the polymer backbone produce highly ordered lamellar stacks with distinct π-π stacking features; subsequently, the long-lived polarons toward hydrogen evolution are observed by transient absorption spectroscopy. In addition, a new nanoparticle synthesis strategy using a methanol/water mixed solvent is first adopted, thereby avoiding the screening effect of surfactants between the nanoparticles and water. Finally, hydrogen evolution rate of 26000 µmolg-1 h-1 is obtained for the copolymer incorporated with both OEG side chains and fluorine substituents under visible-light irradiation (λ> 420nm). This study demonstrates how the glycol side chain strategy can be further optimized for polymer photocatalysts by controlling the backbone planarity.

Stack of cellular lamellae forms a silvered cortex to conceal the opaque organ in a transparent gastropod in epipelagic habitat.

Gelatinous zooplankton in epipelagic environments often have highly transparent bodies to avoid detection by their visual predators and prey; however, the digestive systems are often exceptionally opaque even in these organisms. In a holoplanktonic gastropod, Pterotrachea coronata, the visceral nucleus is an opaque organ located at the posterior end of its alimentary system, but this organ has a mirrored surface to conceal its internal opaque tissue. Our ultrastructural observation proved that the cortex of the visceral nucleus comprised a stack of thin cellular lamellae forming a Bragg reflector, and the thickness of lamellae (0.16 µm in average) and the spaces between the lamellae (0.1 µm in average) tended to become thinner toward inner lamellae. Based on the measured values, we built virtual models of the multilamellar layer comprising 50 lamellae and spaces, and the light reflection on the models was calculated using rigorous coupled wave analysis to evaluate their properties as reflectors. Our simulation supported the idea that the layer is a reflective tissue, and the thickness of the lamella/space must be chirped to reflect sunlight as white/silver light, mostly independent of the angle of incidence. In P. coronata, the cortex of the visceral nucleus comprised multicellular lamellae that form a chirped Bragg reflector. It is distinct in structure from the intracellular Bragg structures of common iridophores. This novel Bragg reflector demonstrates the diversity and convergent evolution of reflective tissue using reflectin-like proteins in Mollusca.

Solvent‐Induced Polymorphism in Non‐Fullerene‐Based Organic Solar Cells

Organic photovoltaics have achieved breakthroughs in power conversion efficiency due to the superior aggregation and packing nature of non‐fullerene acceptors (NFAs). Solution processing and various treatments would tend to form distinct packing motifs for state‐of‐the‐art NFAs. Herein, the solvent‐induced polymorphism for 3,9‐bis(2‐methylene‐(3‐(1,1‐dicyanomethylene)‐indanone))‐5,5,11,11‐tetrakis(4‐hexylphenyl)‐dithieno[2,3‐d:2′,3′‐d′]‐s‐indaceno[1,2‐b:5,6‐b′]dithiophne) (ITIC) prepared by chloroform (CF) and chlorobenzene (CB) is revealed. The packing motif of ITIC exhibits dense π–π stacking from CF induction, which presents red‐shifted absorption and reversible high‐temperature crystallization and melting. Meanwhile, strong lamellar stacking and π–π stacking can be formed in the CB solution with unstable low‐temperature crystallization and melting. Combining in situ absorption spectra and interaction calculation, the stronger preaggregation of ITIC in the CF solution was found to be the main reason for forming a different packing motif from in the CB solution. The packing and thermodynamic features are retained in the PBDB‐T:ITIC blends, though good miscibility weakens characteristic features. Benefiting from the polymorph structure, CB‐processed devices denote more favorable performance but less thermal stability. This research indicates the significant effect of solvent induction for manipulating and optimizing the morphology of organic solar cell devices.

Freezing of Rotation of P3HT Crystallites by PCBM Molecules during Thermal Relaxation of the Blend Thin Films

AbstractPoly(3‐hexylthiophene), or P3HT, is a semicrystalline polymer with charge conduction anisotropy with respect to its different axes, which calls for gaining better control of texture for targeted device applications. A blend system of P3HT and [6,6]‐phenyl C61‐butyric acid methyl ester (PCBM) is studied for understanding the role of PCBM in texture control of P3HT crystallites. 2D grazing incidence diffraction (2D‐GIXD) combined with high resolution grazing incidence X‐ray diffraction (1D‐GIXD) is performed on thin films of pristine P3HT and blend (P3HT/PCBM) thin films prepared by spin coating. Thermal annealing at 110 °C is used for relaxing the films. The lamellar P3HT crystallites preferably orient along the surface plane with lamellar stacking in a vertical direction and have a distribution of orientation with a limiting angle of 44°. In the pristine P3HT system, the rotations of crystallites are confirmed by the retreat of the limiting angle. The observed intensity cross‐over for precursor and annealed samples is again the signature of the rotations of crystallites. For the blend system, the intensity cross‐over is absent and there is no sign of retreat of the limiting angle, which explicitly confirms the blocking of rotation lamellar crystallites. This study provides, for the first time, the clear evidence with unambiguous analysis of blocking of rotation of crystallites due to presence of PCBM, which is explained with an analogy of the “ball‐and‐stick” mechanism. Atomic force microscopy (AFM) studies of surface morphology correlates with the above findings.

Two-Stage Evolution of Gamma-Phase Spherulites of Poly (Vinylidene Fluoride) Induced by Alkylammonium Salt.

We investigated the evolution of the γ-phase spherulites of poly(vinylidene fluoride) (PVDF) added to 1 wt% of tetrabutylammonium hydrogen sulfate during the isothermal crystallization at 165 °C through polarized optical microscopy and light scattering measurements. Optically isotropic domains grew, and then optical anisotropy started to increase in the domain to yield spherulite. Double peaks were seen in the time variation of the Vv light scattering intensity caused by the density fluctuation and optical anisotropy, and the Hv light scattering intensity caused by the optical anisotropy started to increase during the second increase in the Vv light scattering intensity. These results suggest the two-stage evolution of the γ-phase spherulites, i.e., the disordered domain grows in the first stage and ordering in the spherulite increases due to the increase in the fraction of the lamellar stacks in the spherulite without a change in the spherulite size in the second stage. Owing to the characteristic crystallization behavior, the birefringence in the γ-phase spherulites of the PVDF/TBAHS was much smaller than that in the α-phase spherulites of the neat PVDF.

A combined TEM and SAXS study of the growth and self-assembly of ultrathin Pt nanowires

Ultrathin Pt nanowires possess high activity for various electrocatalytic applications. However, little work has focused on understanding their growth mechanisms. Herein, we utilize a combination of time-dependent, ex situ transmission electron microscopy (TEM) and small angle x-ray scattering (SAXS) techniques to observe the growth process in addition to associated surfactant-based interactions. TEM images indicate that initially nanoparticles are formed within 30 s; these small ‘seed’ particles quickly elongate to form ultrathin nanowires after 2 min. These motifs remain relatively unchanged in size and shape up to 480 min of reaction. Complementary SAXS data suggests that the initial nanoparticles, which are coated by a surfactant bilayer, arrange into a bcc superlattice. With increasing reaction time, the bcc lattice disappears as the nanoparticles grow into nanowires, which then self-assemble into a columnar hexagonal structure in which the individual nanowires are covered by a CTAB monolayer. The hexagonal structure eventually degrades, thereby leading to the formation of lamellar stacking phases comprised of surfactant bilayers. To the best of our knowledge, this is the first time that SAXS has been used to monitor the growth and self-assembly of Pt nanowires. These insights can be used to better understand and rationally control the formation of anisotropic motifs of other metallic nanostructures.

Enhanced degradation properties of Mg-Gd-Ni alloys by regulating LPSO morphology

Lamellar long-period stacking order (LPSO) and delaminated bulk-shaped LPSO phases have been introduced into the Mg-Gd-Ni alloys matrix and grain boundaries by adjusting the heat-treatment process to improve the degradation performance. Precipitation of the lamellar LPSO phase in the matrix increased the proportion of the cathode phase, and the corrosion rapidly expanded in the length direction of lamellar LPSO phase, which improved the degradation rate. In addition, the delaminated bulk-shaped LPSO phase provided corrosion channels, which weakened the hindrance of the continuous bulk-shaped LPSO phase to corrosion expansion and further improved the degradation rate. The degradation rate of HT480 reached 19.9 mg/cm2/h in 3 wt% KCl solution at 25 °C, 39% higher than that of as-cast alloy. A new type of rapid degradation model is proposed, namely microstructural distribution of a continuous delaminated bulk-shaped LPSO phase at grain boundaries and of a lamellar LPSO phase within the matrix.

Impact of Side-Chain Hydrophilicity on Packing, Swelling, and Ion Interactions in Oxy-Bithiophene Semiconductors.

Exchanging hydrophobic alkyl-based side chains to hydrophilic glycol-based side chains is a widely adopted method for improving mixed-transport device performance, despite the impact on solid-state packing and polymer-electrolyte interactions being poorly understood. Presented here is a molecular dynamics (MD) force field for modeling alkoxylated and glycolated polythiophenes. The force field is validated against known packing motifs for their monomer crystals. MD simulations, coupled with X-ray diffraction (XRD), show that alkoxylated polythiophenes will pack with a "tilted stack" and straight interdigitating side chains, whilst their glycolated counterpart will pack with a "deflected stack" and an s-bend side-chain configuration. MD simulations reveal water penetration pathways into the alkoxylated and glycolated crystals-through the π-stack and through the lamellar stack respectively. Finally, the two distinct ways triethylene glycol polymers can bind to cations are revealed, showing the formation of a metastable single bound state, or an energetically deep double bound state, both with a strong side-chain length dependence. The minimum energy pathways for the formation of the chelates are identified, showing the physical process through which cations can bind to one or two side chains of a glycolated polythiophene, with consequences for ion transport in bithiophene semiconductors.

Insight into the role of Y addition in the microstructures, mechanical and corrosion properties of as-cast Mg-Gd-Y-Zn-Ca-Zr alloys

The microstructures, mechanical properties, and corrosion behaviors of Mg-4Gd-xY-1Zn-0.5Ca-1Zr (x = 1, 3, and 5 wt.%) alloys under as-cast condition were studied. The results indicate that all the alloys are composed of α-Mg matrix, eutectic phase, and lamellar stacking faults (SFs) located at the outer edge of the α-Mg grains. The plate-like long period stacking ordered (LPSO) structures are found in the alloys with higher Y content. The nano hardness of different phases obeys the following order: eutectic phase > SFs/LPSO structure > α-Mg matrix. Higher Y concentration leads to the nano hardness enhancement of the α-Mg matrix and more uniform hardness distribution. Tensile tests at ambient temperature indicate that Y addition plays a crucial role in improving the yield strength of the as-cast alloys. The corrosion properties of the as-cast alloys after immersion in 3.5 wt.% NaCl solution for 60 h reveal that Mg-4Gd-3Y-1Zn-0.5Ca-1Zr alloy shows a more uniform corrosion morphology and better corrosion resistance than the other two alloys.

Study on preparation of composite carbon rod for high-power electrode from coke with different structural characteristics

Different from lithium-ion batteries, composite carbon rod for high-power electrode was widely used in high-end manufacturing industry due to its good conductivity and low CTE. In this study, semi cokes with different structural characteristics was used as aggregate and coal tar pitch was adopted as binder and impregnant to prepare composite carbon rod for high-power electrode, and the bonding and impregnation behavior was also investigated. It was found that calcination promoted ordered stacking of planar aromatic lamellae of acicular domain texture and aggravated the structural defects of mosaic texture. Coal tar pitch with low aromaticity and high toluene insoluble (TI) as bonded and impregnated pitch possessed higher adhesion but low weight gain ratio after calcination. While higher TI content of coal tar pitch enhanced the weight gain ratio, but the adhesion of composite carbon rod declined. In addition, the carbonaceous sheets derived from coal tar pitch gradually extended and covered the surface of orderly graphited sheets generated from acicular domain texture and contributed to the lowest CTE of 1.43 * 10−6·℃−1 as well as the lowest specific resistance of 6.03μΩ·m. While the structural defects and voids generated from disordered mosaic texture could not be completely filled, thereby resulting in highest CTE of 2.20 * 10−6·℃−1 and highest specific resistance of 9.55μΩ·m.

ω-O-Acylceramides but not ω-hydroxy ceramides are required for healthy lamellar phase architecture of skin barrier lipids

Epidermal omega-O-acylceramides (ω-O-acylCers) are essential components of a competent skin barrier. These unusual sphingolipids with ultralong N-acyl chains contain linoleic acid esterified to the terminal hydroxyl of the N-acyl, the formation of which requires the transacylase activity of patatin-like phospholipase domain containing 1 (PNPLA1). In ichthyosis with dysfunctional PNPLA1, ω-O-acylCer levels are significantly decreased, and ω-hydroxylated Cers (ω-OHCers) accumulate. Here, we explore the role of the linoleate moiety in ω-O-acylCers in the assembly of the skin lipid barrier. Ultrastructural studies of skin samples from neonatal Pnpla1+/+ and Pnpla1-/- mice showed that the linoleate moiety in ω-O-acylCers is essential for lamellar pairing in lamellar bodies, as well as for stratum corneum lipid assembly into the long periodicity lamellar phase. To further study the molecular details of ω-O-acylCer deficiency on skin barrier lipid assembly, we built in vitro lipid models composed of major stratum corneum lipid subclasses containing either ω-O-acylCer (healthy skin model), ω-OHCer (Pnpla1-/- model), or combination of the two. X-ray diffraction, infrared spectroscopy, and permeability studies indicated that ω-OHCers could not substitute for ω-O-acylCers, although in favorable conditions, they form a medium lamellar phase with a 10.8 nm-repeat distance and permeability barrier properties similar to long periodicity lamellar phase. In the absence of ω-O-acylCers, skin lipids were prone to separation into two phases with diminished barrier properties. The models combining ω-OHCers with ω-O-acylCers indicated that accumulation of ω-OHCers does not prevent ω-O-acylCer-driven lamellar stacking. These data suggest that ω-O-acylCer supplementation may be a viable therapeutic option in patients with PNPLA1 deficiency.

One‐step synthesis of ZnS/ZnO using HMDA as precursor and active part for high photocatalytic hydrogen production

AbstractBACKGROUNDThe use of organic molecules to improve the performance of semiconductors (such as using ZnS in hydrogen production) has been widely studied. This work studies the formation of a photocatalyst formed by ZnS/ZnO anchored to an organic molecule (hexamethylenediamine) under different amounts of the organic material and its performance in hydrogen production is evaluated.RESULTSThe materials were synthesized by the precipitation method, forming ZnS/ZnO composite, 3HMDA and 9HMDA materials showed flower‐like structure. The 6HMDA material showed a nanotube like structure and high surface area . Likewise, the anchoring of the organic material forming stacked lamellae is confirmed. Regarding hydrogen production, the most active material was 6HMDA, which showed an excellent performance, producing 3281 μmoles after 5 h of reaction with a production rate of 12 916 μmoles h−1 g‑1; 6HMDA increased the effectiveness with respect to ZnS by a factor of 4.3, while the 9HMDA material increased it 1.5 times.CONCLUSIONThe organic material and the ZnS/ZnO work together to improve the photocatalytic activity and stability of the material, increasing hydrogen production under UV light. These results show that it is possible to obtain an efficient material with excellent photocatalytic performance by a relatively simple synthesis method. © 2022 Society of Chemical Industry (SCI).

Mold temperature- and molar mass-dependent structural formation in micro-injection molding of isotactic polypropylene

The structural formation and development of isotactic polypropylene (iPP) upon the micro-injection molding process was investigated at different mold temperatures and molecular weights utilizing a real-time synchrotron radiation small angle X-ray scattering (SAXS) technique combined with a customized micro-injection molding apparatus. Shish-kebab structure and parent-daughter lamellae were found to be formed during micro-injection molding for all iPP samples. In the case of kebab lamellae, a considerable growth in the long period and in the average thickness of lamellar crystallites and amorphous domains is observed at initial stages of crystallization for samples molded at varying temperatures. This effect is caused by the successive formation of thin lamellae in the outer layer and thick lamellae in the inner layer during the manufacturing process as evidenced by the spatial distribution of the crystalline lamellae across the thickness. In addition, the length of the shish formation increases remarkably at the onset of crystallization, the extent of which is dependent on the mold temperature. Despite the large changes of the lamellar stacks and the shish misorientation, the final length of the shish remains essentially unchanged when varying mold temperature. Since there is a critical orientation molecular weight above which the chains are stretched and oriented to form stable shish, the iPP sample with a low molar mass exhibits an overall decrease in the scattering intensity of SAXS patterns compared to the high molecular weight polypropylene. • The structural formation of iPP is investigated utilizing a customized micro-injection molding device. • Shish-kebab and parent-daughter lamellae are formed during micro-injection molding. • A considerable increase in the long period is observed at initial stages of crystallization. • The length of the shish formation increases remarkably at the onset of crystallization. • The final shish length remains essentially unchanged when varying mold temperature.

In-Situ X-Ray Analyses of Structural Change During Drawing and Shrinking of Linear Low-Density Polyethylene Film

Structural changes during the drawing and shrinking of linear low-density polyethylene (LLDPE) film are analyzed through in-situ X-ray measurements. A synchrotron radiation source enables simultaneous analyses combining small-angle X-ray scattering (SAXS) and wide-angle X-ray diffraction (WAXD). During drawing, the original unoriented SAXS and WAXD patterns transformed into line and spot patterns, indicating the orientation of both lamellar stacking and the molecular axis along the drawing direction. During the subsequent shrinking these patterns are retained, suggesting the tilted lamellar and molecular chains. A possible model for structural changes indicates that tie molecules between lamellae effectively transmit drawing and shrinking stresses, which contributes to desirable actuation properties.

Construction and electrochemical energy storage performance of free-standing hexagonal Ti3C2 film for flexible supercapacitor

In order to improve the specific capacitance of flexible supercapacitor and solve the specific capacitance attenuation problem of MXene Ti3C2 electrode material caused by stacking of its own lamellae under long cycle charge and discharge, this work innovatively adopts “Lewis acid melting salt method & microwave assisted etching method” to construct hexagonal Ti3AlC2 powder into free-standing hexagonal Ti3C2 film. Compared with free-standing common Ti3C2 film, the microstructure and morphology of hexagonal Ti3C2 film was characterized, and the electrochemical energy storage performance and mechanism was analyzed. It is found that this method can effectively increase the crystal plane spacing of Ti3C2 and inhibit the lamellar stacking. The specific capacitance retention rate of the film is 97.37% after 10,000 cycles of charge and discharge, and the attenuation is small. The charge storage of the film mainly comes from the contribution of surface capacitance. At 100 mV/s, the contribution rate of surface capacitance is 71.42%. This is due to the increase of the surface group -O of Ti atom of hexagonal Ti3C2, which increases the pseudocapacitance. This provides a new idea and theoretical support for the research and development of long cycle stable flexible supercapacitor with high specific capacitance.

Structure and Morphology of Crystalline Syndiotactic Polypropylene-Polyethylene Block Copolymers.

A study of the structure and morphology of diblock copolymers composed of crystallizable blocks of polyethylene (PE) and syndiotactic polypropylene (sPP) having different lengths is reported. In both analyzed samples, the PE block crystallizes first by cooling from the melt (at 130 °C) and the sPP block crystallizes after at a lower temperature. Small angle X-ray scattering (SAXS) recorded during cooling showed three correlation peaks at values of the scattering vector, q1 = 0.12 nm−1, q2 = 0.24 nm−1 and q3 = 0.4 nm−1, indicating development of a lamellar morphology, where lamellar domains of PE and sPP alternate, each domain containing stacks of crystalline lamellae of PE or sPP sandwiched by their own amorphous phase of PE or sPP. At temperatures higher than 120 °C, when only PE crystals are formed, the morphology is defined by the formation of stacks of PE lamellae (17 nm thick) alternating with amorphous layers and with a long period of nearly 52 nm. At lower temperatures, when crystals of sPP are also well-formed, the morphology is more complex. A model of the morphology at room temperature is proposed based on the correlation distances determined from the self-correlation functions extracted from the SAXS data. Lamellar domains of PE (41.5 nm thick) and sPP (8.2 nm thick) alternate, each domain containing stacks of crystalline lamellae sandwiched by their own amorphous phase, forming a global morphology having a total lamellar periodicity of 49.7 nm, characterized by alternating amorphous and crystalline layers, where the crystalline layers are alternatively made of stacks of PE lamellae (22 nm thick) and thinner sPP lamellae (only 3.5 nm thick).

Stable TiVCTx/poly-o-phenylenediamine composites with three-dimensional tremella-like architecture for supercapacitor and Li-ion battery applications

Two-dimensional double transition metal carbides and nitrides (MXenes) with unique out-of-plane ordering of the two metal atoms, have distinct and advantageous electrical properties owing to their chemical versatility and structural intricacy signify. However, MXenes are inclined to easily oxidized unstable surface, and lamellar structure agglomeration or stack, which impede their practicable application prospect in energy utilization and storage. Here, we propose a new strategy of spontaneous transforming few-layered TiVCTx MXene nanosheets directly into three-dimensional (3D) stable tremella-like architecture TiVCTx/poly-o-PD composites (N-TiVCTx) by utilizing o-phenylenediamine (oPD) as the monomer of oxidant-free polymerization. Meanwhile, the electrochemical performance of the supercapacitor using TiVCTx and N-TiVCTx in acidic and neutral electrolyte was examined for the first time. Notedly, N-TiVCTx composites show outstanding electrochemical capacitance property with a high specific capacitance of 282F g−1 at 10 mV s−1. Compared to TiVCTx, the capacitance was increased by 50 %. Besides, the 3D N-TiVCTx electrodes exhibit well stable pseudocapacitive charge storage with capacity up to 415.6 mAh g−1 at 0.1A g−1 and retain outstanding performance of 224 mAh g−1 at 2 A g−1 for lithium ion storage. The N-TiVCTx MXene greatly increased the stability consist of thermal stability, preferably chemical and electrochemical stability. Our work broadens the application of TiVCTx as electrode materials in energy storage domain and provides tactics to improve the other few-layered MXenes energy storage capacity as well as chemical stability.

Enhancing the Intermolecular Interactions of Ladder-Type Heteroheptacene-Based Nonfullerene Acceptors for Efficient Polymer Solar Cells by Incorporating Asymmetric Side Chains

Enhancing the Intermolecular Interactions of Ladder-Type Heteroheptacene-Based Nonfullerene Acceptors for Efficient Polymer Solar Cells by Incorporating Asymmetric Side Chains

Size-dependent filling effect of crystalline celluloses in structural engineering of composite oleogels

Oleogels are a class of solid-fat mimetics that contain a large fraction of oil. Most of these materials have low stiffness and poor oil-binding capacity at commercially viable concentrations, which limits their application in the food and cosmetic industries. To improve their mechanical behavior, we exploited the concepts of particulate-filled materials by developing oil-continuous monoglyceride composites reinforced with crystalline cellulose of various sizes. Cellulose was used as the reinforcing filler material due to its strength, biodegradability, and abundance. The composites gradually stiffened and became more brittle with a progressive increase of the cellulose weight fraction as the maximum packing fraction of fillers approached. This was manifested as an increase in the viscoelastic moduli and yield stress, consistent with the size of the filler. Based on differential scanning calorimetry, X-ray diffraction, X-ray scattering analyses, and microscopic analyses, the inert surface of crystalline celluloses provided a solid substrate for the crystallization of monoglycerides, favoring the lamellar stacking of monoglyceride molecules during the composite oleogel formation regardless of the cellulose size. The present study suggests that cellulose is a suitable bio-based filler material to obtain mechanically strong oleogels suitable for high-shear applications e.g., in food and pharmaceutical industries.

Boosting capacitive performance of manganese oxide nanorods by decorating with three-dimensional crushed graphene

This work reports the rational design of MnOx nanorods on 3D crushed reduced graphene oxide (MnOx/C-rGO) by chemical reduction of Ni-incorporated graphene oxide (GO) followed by chemical etching to remove Ni. The resulting MnOx/C-rGO composite synergistically integrates the electronic properties and geometry structure of MnOx and 3D C-rGO. As a result, MnOx/C-rGO shows a significantly higher specific capacitance (Csp) of 863 F g−1 than MnOx/2D graphene sheets (MnOx/S-rGO) (373 F g−1) and MnOx (200 F g−1) at a current density of 0.2 A g−1. Furthermore, when assembled into symmetric supercapacitors, the MnOx/C-rGO-based device delivers a higher Csp (288 F g−1) than MnOx/S-rGO-based device (75 F g−1) at a current density of 0.3 A g−1. The superior capacitive performance of the MnOx/C-rGO-based symmetric device is attributed to the enlarged accessible surface, reduced lamellar stacking of graphene, and improved ionic transport provided by the 3D architecture of MnOx/C-rGO. In addition, the MnOx/C-rGO-based device exhibits an energy density of 23 Wh kg−1 at a power density of 113 Wkg−1, and long-term cycling stability, demonstrating its promising potential for practical application.Graphical