Hybrid Nanosheets Research Articles

Anion Storing Boron Nitride Hybrid Nanosheets for High-Performance Dual Ion and Zinc Alkaline Full Cells.

Hexagonal boron nitride (BN), a well-known member of 2D materials, has a structure similar to graphene and is often referred to as white graphene. Despite its unique physical and chemical properties for energy storage applications, there have been very few studies on how BN stores anion carriers. Herein, the hybrid architecture and anion storage mechanism of BN nanosheets for high-performance hybrid energy storage full cells based on dual-ion and Zinc (Zn) alkaline systems is demonstrated. The chemical bonding between BN and reduced graphene oxide (rGO) is attributed to the formation of the heterointerface, which facilitates the charge transfer kinetics during an OH storing process. Based on the reversible surface redox reaction of BN and rGO hybrid (BN@rGO) confirmed by computational and spectroscopic analyses, the BN@rGO electrode is applied to both Na and OH dual-ion and Zn alkaline full cells. In the dual-ion system, Ti3C2‖BN@rGO full cells extended the operating voltage range up to 1.7V, delivering a cell capacity of 49.4mAhg-1 at 1000mAg-1 and retaining 80% of its initial capacity after 40000 cycles. In the Zn alkaline system, Zn‖BN@rGO full cells achieved a cell capacity of 58.1mAhg-1 at 1000mAg-1 and retained 80% capacity over 90000 cycles.

Preparation and sodium storage properties of CoFe2O4 composite S N co-doped RGO

The application value of iron-base binary oxide in sodium-ion batteries has been widely concerned by researchers, and CoFe2O4 has a better development prospect because of its cost efficiency. However, the CoFe2O4 will produce volume expansion during the reaction, resulting in the collapse of the material structure. This paper created the ground-breaking CFO/SNRGO nanocomposite structure by using a microwave approach. This intricate arrangement entails CoFe2O4 nanoparticles firmly adhering to S and N co-doped graphene hybrid nanosheets. The prepared CFO/SNRGO nanocomposite showcased remarkable electrochemical capabilities. Through the uniform integration of CoFe2O4 nanoparticles onto the SNRGO hybrid nanosheets, we managed to minimize the stacking between SNRGO nanosheets and reduce the size of the CoFe2O4 nanoparticles. Additionally, the SNRGO serves as a buffer layer, allowing it to adjust to variations in volume and stop the CoFe2O4 nanoparticles from collapsing while Na+ is being embedded or removed. This cooperative amalgamation of SNRGO and CoFe2O4 contributes to the outstanding electrochemical performance observed in the CFO/SNRGO nanocomposites. After 200 cycles at an electrical concentration of 0.05 A g−1, the CFO/SNRGO nanotechnology demonstrated a notable 357.3 mAh g−1 bidirectional ability. and sustained excellent rate performance. Even when subjected to an increased electrical concentration of 1.5 A g−1, the reversible capacity remained steady at 174 mAh g−1. These impressive outcomes are due to the robust coupling between the CoFe2O4 nanoparticles and SNRGO within the nanocomposites.

Preparation and sodium storage properties of Ni-CoFe2O4/Reduced graphene oxide

The Ni-doped CoFe2O4 graphene composites (Ni-CFO/RGO) have been successfully prepared using the microwave-assisted method. The substance is a novel nanocomposite structure in which CoFe2O4 nanoparticles are tightly and uniformly attached to graphene hybrid nanosheets. The synergistic effect of Ni doping and CoFe2O4 can reduce the volume expansion of CoFe2O4 in the reaction process and inhibit the stacking of graphene. Because the Ni-CFO/RGO composite is structurally stable during the electrochemical reaction, it has a good theoretical capacity. Excellent carbon composite can further enhance the electron transport performance and structural stability of the material, thereby improving the electrochemical performance and cycle life of the material. Doping Ni2+ into metal oxides can not only form oxygen vacancies, and improve the transport capacity of sodium ions, but also broaden the electron transport channel. In addition, the catalyst can form a composite structure with metal oxide, which can effectively inhibit its volume expansion. At the same time, reacting with carbon materials, can also effectively reduce the accumulation of carbon, thereby reducing its resistance. After 200 cycles at a current density of 0.05 A g−1, it can provide a high sodium storage capacity of 380.6 mAh g−1, which still keeps 203.4 mAh g−1 at 1.5 A g−1.

Experimental insights into the stability of graphene oxide nanosheet and polymer hybrid coupled by ANOVA statistical analysis

The synergistic potential of using graphene oxide (GO) nanosheets and hydrolyzed polyacrylamide (HPAM) as GO enhanced polymer hybrid (GOeP) for enhancing oil recovery (EOR) purposes has drawn attention. However, the hybridization method and stability of GOeP have not been comprehensively studied. To cover this gap, the current study evaluates the stability of GOeP under different conditions, including temperatures such as 60 and 80 °C, high and low salinities, and the presence of Mg2+ ions (6430 and 643 ppm). Hence, GO nanosheets were synthesized and characterized through XRD, Raman, FTIR, and DLS techniques. The performance of five preparation methods was assessed to determine their ability to produce stable hybrids. Zeta potential and sedimentation methods, coupled with the ANOVA statistical technique, were used for measuring and interpreting stability for 21 days. Results revealed that the stability of GOeP in the presence of brine is influenced by hydrolyzation duration, the composition of the water used in polymer hydrolyzation, the form of additives (being powdery or in aqueous solution), and the dispersion quality, including whether the GO solution was prediluted. The results revealed that the positive impact of higher temperatures on the long-term stability of GOeP is approximately seven times less significant than the reduction in stability caused by salinity. Under elevated salinity conditions, a higher Mg2+ concentration led to an 80% decrease in long-term stability, whereas the temperature impact was negligible. These findings highlight the potential of GOeP for EOR applications, offering insights into optimizing stability under challenging reservoir conditions.

Well-Ordered Nanoparticles/Block Copolymer Nanosheets with a Controllable Location of Nanoparticles.

Precisely controlling the spatial distributions and arrangements of metal nanoparticles (NPs) into block copolymers is of great importance for fabricating novel nanomaterials with the desired optical and electronic properties. Herein, we develop a simple yet versatile strategy to prepare organic/inorganic nanosheets formed by the coassembly of polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) and PS tethered gold nanoparticles (AuNPs@PS) within emulsion droplets. The arrangement of the AuNPs@PS building blocks within the block copolymers (BCP)/AuNPs nanosheets can be adjusted by tuning the effective size ratio (λeff), which can be controlled by the core diameter of the AuNPs and the molecular weight of the PS. Furthermore, the content of the AuNPs is also another essential parameter to manipulate the structures of the nanosheets with the specific λeff. Thus, the BCP/AuNPs hybrid nanosheets with controllable distributions and arrangements of the AuNPs were successfully prepared via tuning of λeff and the content of AuNPs. This study provides a facile way to fabricate well-ordered hybrid nanosheets.

V2O3/VO2@NC@GO ultrathin nanosheets as a high-performance cathode for aqueous zinc-ion batteries

Recently, vanadium oxides have attracted much attention as advanced cathodes for aqueous zinc-ion batteries on account of their high theoretical specific capacity, multi-electron transfer and easy synthesis; however, structural instability and poor conductivity of the materials limit their practical application. Herein, N-doped carbon-coated V2O3/VO2 hybrid nanosheets were encapsulated into graphene oxide (V2O3/VO2@NC@GO) as an advanced cathode for aqueous zinc-ion batteries by the combined process of hydrothermal treatment, high-temperature annealing and freeze drying. The multi-valence of vanadium element activates diverse redox reactions and thus results in high specific capacity, while graphene oxide and N-doped carbon layer derived from polyvinyl pyrrolidone establish an efficient conductive network for electronic transfer and provide a rigid skeleton for enhancing the structural stability of the hybrid nanosheets. Benefiting from the above unique advantages of composition and micromorphology, the V2O3/VO2@NC@GO cathode exhibits excellent reaction dynamics and rapid electron transfer, generating high specific capacities of 493.0 mAh g−1 at 0.5 A g−1 and 411.9 mAh g−1 at 5 A g−1 and outstanding long-term cycling performance with a retention of 92.4 % after 1000 cycles at 5 A g−1. This work offers a viable approach for developing high-performance vanadium oxide-based cathodes for aqueous zinc-ion batteries by enriching the valence states of vanadium and encapsulating active materials into highly conductive carbon materials.

Concurrently boosted oxygen reduction/evolution electrocatalysis over highly loaded CoNi/onion-like carbon hybrid nanosheets

Balancing the bicatalytic activities and stabilities between oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is a critical yet challenging task for exploring advanced rechargeable Zinc–air batteries (ZABs). Herein, a hybrid nanosheet catalyst with highly dispersed and densified metallic species is developed to boost the kinetics and stabilities of both ORR and OER concurrently. Through a progressive coordination and pyrolysis approach, we directly prepared highly conductive onion-like carbon (OLC) accommodating dense ORR-active CoNC species and enveloping high-loading OER-active CoNi-synergic structures within a porous lamellar architecture. The resultant CoNi/OLC nanosheet catalyst delivers better ORR and OER activities showcasing a smaller reversible oxygen electrode index (ΔE = Ej10 − E1/2) of 0.71 V, compared to state-of-the-art Pt/C-RuO2 catalysts (0.75 V), Co/amorphous carbon polyhedrons (0.80 V), NiO nanoparticles with higher Ni loading (1.00 V), and most CoNi-based bifunctional catalysts reported so far. The rechargeable ZAB assembled with the developed catalyst achieves a remarkable peak power density of 270.3 mW cm−2 (172 % of that achieved by Pt/C + RuO2) and ultrahigh cycling stability with a negligible increase in voltage gap after 800 h (110 mV increase after 200 h for a Pt/C + RuO2-based battery), standing the top level of those ever reported.

Mechanical properties of C3N-BN hybrid nanosheets: Insights from molecular dynamics simulations

Molecular dynamics simulations have been utilized to explore the mechanical properties of the C3N-BN hybrid nanosheet across varying temperatures and strain rates, as well as in the presence of two different types of defects: circular holes and single vacancy atoms introduced into the hybrid structure. The findings revealed that the hybrid material shows intermediate mechanical properties compared to pure C3N and BN. The mechanical characterization of the hybrid suggests that variations in mechanical parameters remain relatively stable across different strain rates. However, temperature changes significantly affect the mechanical properties of the hybrid, with the highest failure stress recorded as 123.70 (GPa), failure strain of 21.57 %, and Young's Modulus of 747.25 (GPa) at 100 Kelvin. Expanding the hole radius decreases failure stress by approximately 76 %, 56 %, and 82 % when holes are exerted in the interface, BN, and CN sides of the hybrid, respectively, and reduces Young's modulus by about 65 %, 67 %, and 66 %. Introducing circular holes within the BN domain enhanced the hybrid structure's strength and resilience, demonstrating BN's superiority over C3N. Therefore, placing holes in the BN region is recommended for achieving superior mechanical properties in such structures. The introduction of single-atom vacancies revealed that carbon vacancies induced a far more significant mechanical strength reduction than vacancies of other atoms.

Polymer-functionalized metal-organic framework nanosheet membranes for efficient CO2 capture

Two-dimensional metal-organic frameworks (2DMOFs) have emerged as highly appealing candidates as advanced separation membrane materials. However, constructing 2DMOF membranes with appropriate channel sizes to separate CO2 from N2 remains a great challenge. Here, we propose an in-situ crystallization approach to synthesize CO2-philic-polymer functionalized Zr-based MOF nanosheets, enabling the fabrication of efficient CO2 capture membranes. The in-situ MOF crystallization with polyethylenimine (PEI) polymers leads to a uniform distribution of amines, resulting in the formation of PEI-NUS hybrid nanosheet characterized by both high porosity and strong affinity to CO2. These nanosheets are assembled into ultrathin lamellar membranes with thicknesses ranging from 40 to 120 nm. The amines of PEI polymers significantly facilitate the CO2 transfer as reaction carriers, resulting in a substantially improved CO2/N2 separation performance with a CO2 permeance of 410 GPU and a CO2/N2 selectivity of 90, which are among the best for MOF membranes in CO2 separation. This in-situ functionalization strategy paves the way for the fabrication of ultrathin 2D membranes for various separations.

Multihole Ce-doped NiSe2/CoP hybrid nanosheets for improved electrocatalytic alkaline water and simulative seawater oxidation

The investigation of cost-effective and highly efficient electrocatalysts for alkaline water and simulative seawater oxidation is essential to the conversion and storage of renewable energy. In this paper, the Ce–NiSe2/CoP catalyst with multihole and ultrathin nanosheet structure is generated. The unique structural characteristics of Ce–NiSe2/CoP heterojunction nanosheets contribute the excellent OER performance under different alkaline 1 M KOH and simulated seawater (1 M KOH + 0.5 M NaCl) electrolytes. Specifically, this catalyst exhucture is generated. The unique structural characteristics of Ce–NiSe2/CoP heterojunction nanosheets conibits the low overpotentials of 287 and 304 mV at the current density of 10 mA cm−2, along with the Tafel slopes of 87.1 and 78.8 mV dec−1 in two solutions, respectively. Moreover, the Ce–NiSe2/CoP target product also displays good stability. The present study introduces a promising strategy for the advancement of high-performance electrocatalysts in green energy field.

Stable lithium storage of hierarchical Zn2SiO4/C micro-/nanospheres enabled by in-situ introduction of an endogenous Zn4Si2O7(OH)2

Zn2SiO4 with high natural abundance and low cost has attracted a lot of attention in lithium-ion battery (LIB) anode realm, but its electrochemical performances are poor (such as short cyclic life and fast capacity decay). Herein, the electrochemical performances of Zn2SiO4 are significantly improved through a novel and simple strategy, including morphological engineering and especially the in-situ introduction of an endogenous Zn4Si2O7(OH)2 by simply regulating the carbonization temperature. The findings show that the conformal carbon-coated ultrathin Zn2SiO4/Zn4Si2O7(OH)2 hybrid nanosheets assembled hierarchical micro-/nanospheres (ZSO/ZSOH@C) are endowed with stable structure, enhanced conductivity, improved Li+ diffusion kinetics and a LiF-rich stable SEI layer during charge/discharge process. Therefore, the ZSO/ZSOH@C anode manifests superior electrochemical performance, with 475.5 and 372.1 mAh g−1 at 200 and 2000 mA g−1 after 350 and 400 cycles, respectively. The structure-property correlations of ZSO/ZSOH@C anode are systematically studied and demonstrate that the characteristically hierarchical structure and the synergistic effects between Zn2SiO4 and Zn4Si2O7(OH)2 are responsible for the superior electrochemical performances of the ZSO/ZSOH@C anode. Finally, this work may inspire ideas for the preparation of high-performance Zn2SiO4 or other silicates for LIB anodes.

Congo red dye reduction mediated by the electron (e−) transfer route of BH4 − ions using synthesized NiCo2O4/rGO hybrid nanosheets

The treatment of toxic organic pollutants is extremely important for the conservation of clean air, soil, and water. In this study, (reduced graphene oxide) NiCo2O4/ rGO hybrid nanocomposite was prepared by a facile hydrothermal technique and employed for organic dye adsorption from wastewater. The synthesized NiCo2O4/rGO hybrid nanocomposite was studied using FTIR, XRD, SEM, TEM, BET, Raman spectroscopy, and UV–visible. The physical characterizations prove the deposition of NiCo2O4 particles on the rGO surface. The transmission electron microscope image demonstrated that the NiCo2O4 particles with an average size of ∼46 nm was dispersed on the rGO surface. The obtained nanoparticles show a higher specific surface area of 56.4 m2 g−1. Adsorption dynamics as investigated by time and concentration variation show that the adsorption data follows pseudosecond order kinetics and the Langmuir isotherm model, with a maximum adsorption capacity of 106.2 mg g−1, indicating homogeneous physiochemical adsorption of CR dye on the adsorbent surface. Besides, the catalytic effectiveness of synthesized nanocomposite towards Congo red (CR) dye reduction mediated by the electron (e−) transfer route of BH4 − ions was explained in detail. The electrostatic interaction used between the NiCo2O4/rGO hybrid composite and Congo red increased the adsorption ion effectiveness of the dye sample.

In-situ synthesis of Ni2P/Ti3C2Tx hybrid nanosheets for enhanced alkaline hydrogen evolution reaction

The development of efficient and low-cost electrocatalysts for hydrogen in alkaline media is crucial for green energy production. Herein, we report an in-situ synthesis strategy of Ni2P/Ti3C2Tx hybrid nanosheets on nickel foam (NF), which is effectively achieved by direct phosphorization of Ni-MOF/Ti3C2Tx. The Ni2P/Ti3C2Tx hybrid nanosheets not only inherit the morphology of the Ni-MOF/Ti3C2Tx precursor, but also possess electronic coupling effects, thereby exhibiting enhanced electrocatalytic performance toward alkaline hydrogen evolution reaction (HER).

Ultrathin TiS2@N,S-Doped Carbon Hybrid Nanosheets as Highly Efficient Photoresponsive Antibacterial Agents.

Nanobactericides are employed as a promising class of nanomaterials for eradicating microbial infections, considering the rapid resistance risks of conventional antibiotics. Herein, we present a pioneering approach, reporting the synthesis of two-dimensional titanium disulfide nanosheets coated by nitrogen/sulfur-codoped carbon nanosheets (2D-TiS2@NSCLAA hybrid NSs) using a rapid l-ascorbic acid-assisted sulfurization of Ti3C2Tx-MXene to achieve efficient alternative bactericides. The as-developed materials were systematically characterized using a suite of different spectroscopy and microscopy techniques, in which the X-ray diffraction/Raman spectroscopy/X-ray photoelectron spectroscopy data confirm the existence of TiS2 and C, while the morphological investigation reveals single- to few-layered TiS2 NSs confined by N,S-doped C, suggesting the successful synthesis of the ultrathin hybrid NSs. From in vitro evaluation, the resultant product demonstrates impressive bactericidal potential against both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria, achieving a substantial decrease in the bacterial viability under a 1.2 J dose of visible-light irradiation at the lowest concentration of 5 μg·mL-1 compared to Ti3C2Tx (15 μg·mL-1), TiS2-C (10 μg·mL-1), and standard antibiotic ciprofloxacin (15 μg·mL-1), respectively. The enhanced degradation efficiency is attributed to the ultrathin TiS2 NSs encapsulated within heteroatom N,S-doped C, facilitating effective photogenerated charge-carrier separation that generates multiple reactive oxygen species (ROS) and induced physical stress as well as piercing action due to its ultrathin structure, resulting in multimechanistic cytotoxicity and damage to bacterial cells. Furthermore, the obtained results from molecular docking studies conducted via computational simulation (in silico) of the as-synthesized materials against selected proteins (β-lactamasE.coli/DNA-GyrasE.coli) are well-consistent with the in vitro antibacterial results, providing strong and consistent validation. Thus, this sophisticated study presents a simple and effective synthesis technique for the structural engineering of metal sulfide-based hybrids as functionalized synthetic bactericides.

2D Perovskite Nanosheet‐Driven Polymeric Nanocomposites as Gate Dielectrics for Flexible Negative‐Capacitance Applications

AbstractDesigning composite gate dielectrics tailored by incorporating inorganic perovskite nanofillers into a polymer matrix to develop flexible low‐voltage transistors can be challenging because homogeneous dispersion of nanomaterials in the matrix is difficult to achieve; thus, degradation of the electrically insulating properties of nanocomposite layers is often observed. In this study, nanocomposite dielectrics are presented that consist of 2D Ba5Ta4O15 nanosheets (BTO NSs) for the first time. Perovskite BTO is introduced using the Langmuir–Blodgett method to construct a precise and pinhole‐free interface for the homogeneous assembly of 2D nanosheets. Its high k value and ferroelectric properties, which arise from the perovskite structure, can be harnessed to achieve attractive polarization and remarkable electronic properties. The 2D BTO NSs can also be utilized as phase crystallization fillers to enhance the ferroelectric properties of polyvinylidene fluoride (PVDF). Additionally, the multilayer PVDF/perovskite nanosheet hybrid dielectric, which reaches an unprecedentedly high dielectric constant of 22.4, exhibits effective dielectric relaxation related to the interfacial induced ferroelectric polarization and decisive negative‐capacitance response.

Different M-doped Ni3S2/FeS (M=Co, Cr, Cu, Zn) hybrid nanosheet arrays for overall urea splitting and seawater oxidation reaction

Hydrogen production by electrolysis of water is gradually becoming the main way to obtain green energy, but due to the scarcity of fresh water resources in the world, so the study of urea and seawater electrolysis has become an important work. In this experiment, different metal ions M (M=Co, Cr, Cu, Zn) doped Ni3S2/FeS were investigated as catalysts with good catalytic activity in hydrogen evolution reaction (HER) as well as in urea oxidation reaction (UOR) in urea electrolyte, and Co-Ni3S2/FeS and Cr-Ni3S2/FeS, which performed well in HER and UOR, were assembled into an electrolytic cell for the overall urea decomposition (1.50 V @ 10 mA cm−2). Density Functional Theory (DFT) calculations demonstrated that Co-Ni3S2 possesses a lower free energy for H, while FeS possesses a higher density of states (DOS) near the Fermi energy level, and such a composite structure promotes significantly the catalytic activity of HER. The catalytic effect of oxygen evolution reaction (OER) was further investigated in the seawater electrolyte, and the results showed that the performance of Co-Ni3S2/FeS catalyst was better, and certain ions in seawater affected durability of the catalyst. The electronic structure of the catalyst was investigated through the characterization of the catalyst and combined with the special morphology jointly promote the catalytic reaction in electrolysis experiments, which provides a candidate catalyst for electrolysis of urea and seawater oxidation reaction.

PH-sensitive release of nitric oxide gas using peptide-graphene co-assembled hybrid nanosheets

Nitric oxide (NO) donating drugs such as organic nitrates have been used to treat cardiovascular diseases for more than a century. These donors primarily produce NO systemically. It is however sometimes desirable to control the amount, location, and time of NO delivery. We present the design of a novel pH-sensitive NO release system that is achieved by the synthesis of dipeptide diphenylalanine (FF) and graphene oxide (GO) co-assembled hybrid nanosheets (termed as FF@GO) through weak molecular interactions. These hybrid nanosheets were characterised by using X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, zeta potential measurements, X-ray photoelectron spectroscopy, scanning and transmission electron microscopies. The weak molecular interactions, which include electrostatic, hydrogen bonding and π-π stacking, are pH sensitive due to the presence of carboxylic acid and amine functionalities on GO and the dipeptide building blocks. Herein, we demonstrate that this formulation can be loaded with NO gas with the dipeptide acting as an arresting agent to inhibit NO burst release at neutral pH; however, at acidic pH it is capable of releasing NO at the rate of up to 0.6 μM per minute, comparable to the amount of NO produced by healthy endothelium. In conclusion, the innovative conjugation of dipeptide with graphene can store and release NO gas under physiologically relevant concentrations in a pH-responsive manner. pH responsive NO-releasing organic-inorganic nanohybrids may prove useful for the treatment of cardiovascular diseases and other pathologies.

Comparative study of interfacial charge transfer at the junction between CuInS2:In2S3/g-C3N4 photocatalysts for sacrificial hydrogen evolution activity

The quest for sustainable and efficient renewable energy sources has escalated in recent years, with photocatalytic hydrogen production gaining prominence due to its potential to harness solar energy for clean fuel generation. In this study, we design 2D/2D heterostructure CuInS2:In2S3/g-C3N4 nanosheets utilizing electrostatic interaction for hydrogen evolution reaction under visible light irradiation. Integrating CuInS2:In2S3 and g-C3N4 layers to form an interfacial 2D:2D heterostructure results in a broad light absorption range, effective charge separation, and excellent stability. The heterostructure ensures efficient interfacial charge transfer pathways, mitigating electron-hole recombination and promoting hydrogen evolution. The hybrid nanosheets prepared with the hydrothermal method exhibited ∼40-fold synergistic enhancement in hydrogen production and long-term stability. The synergistic boost in activity resulted from the formation of S-scheme heterojunctions (CuInS2/g-C3N4 and CuInS2/In2S3) within hybrid nanosheets.

Synthesis and Characterization of Modified Centrifuged-Electrospun Carbon Nanofibers for High-Performance Supercapacitor Electrodes

Background: Incorporating novel multifunctional effective materials into supercapacitors electrode is an ongoing requirement for hybrid supercapacitors with enhanced electrochemical performance. Methods: Herein, modified plasma-grafted multiwalled carbon nanotubes (CMS) with improved dispersion are embedded within centrifugal-spun carbon nanofibers as a hierarchical template (CNFs-CMS) to facilitate the growth of subsequent active materials. CNFs-CMS is then electroless plated with acicular nickel (Ni) balls, followed by one-step hydrothermal co-deposition to grow Ni(OH)2-MnO2 hybrid nanosheets. Significant findingsA binder-free, 3D interconnected nanostructures of CNFs-CMS@Ni@Ni(OH)2-MnO2 electrode material is employed for an all-in-one hybrid supercapacitor that exhibits excellent electric double layer (EDLC), battery-like and pseudocapacitance (PC) properties, along with a high surface area (665 m2 g−1) and conductivity (2.96 S cm−1). The as-fabricated electrode demonstrates specific capacitance (Cs) of 1063.33 F g−1 at a high current density of 20 A g−1 in 3M KOH electrolyte, maintaining capacitance retention of 92.5 % after 10,000 galvanostatic charge-discharge cycles. An asymmetric supercapacitor pairing CNFs-CMS@Ni@Ni(OH)2-MnO2 with CNFs-CMS is established, attributes comparably high energy density (52.54 Wh kg−1) and power density (59 kW kg−1) across a potential window of 1.2 V.

Conductive Nanosheets Fabricated from Au Nanoparticles on Aqueous Metal Solutions under UV Irradiation.

Highly transparent, conductive nanosheets are extremely attractive for advanced opto-electronic applications. Previously, we have demonstrated that transparent, conductive Au nanosheets can be prepared by UV irradiation of Au nanoparticle (AuNP) monolayers spread on water, which serves as the subphase. However, thick Au nanosheets cannot be fabricated because the method is not applicable to large Au NPs. Further, in order to fabricate nanosheets with different thicknesses and compositions, it is necessary to prepare the appropriate NPs. A strategy is needed to produce nanosheets with different thicknesses and compositions from a single type of metal NP monolayer. In this study, we show that this UV irradiation technique can easily be extended as a nanosheet modification method by using subphases containing metal ions. UV irradiation of 4.7 nm AuNP monolayers on 480 µM HAuCl4 solution increased the thickness of Au nanosheets from 3.5 nm to 36.5 nm, which improved conductivity, but reduced transparency. On the other hand, the use of aqueous AgNO3 and CH3COOAg solutions yielded Au-Ag hybrid nanosheets; however, their morphologies depended on the electrolytes used. In Au-Ag nanosheets prepared on aqueous 500 µM AgNO3, Au and Ag metals are homogeneously distributed throughout the nanosheet. On the other hand, in Au-Ag nanosheets prepared on aqueous 500 µM CH3COOAg, AuNPs still remained and these AuNPs were covered with a Ag nanosheet. Further, these Au-Ag hybrid nanosheets had high conductivity without reduced transparency. Therefore, this UV irradiation method, modified by adding metal ions, is quite effective at improving and diversifying properties of Au nanosheets.