Hybrid Nanosheets Research Articles

Corrigendum: Synthesis of Graphite Oxide/Cobalt Molybdenum Oxide Hybrid Nanosheets for Enhanced Electrochemical Performance in Supercapacitors and the Oxygen Evolution Reaction

Corrigendum: Synthesis of Graphite Oxide/Cobalt Molybdenum Oxide Hybrid Nanosheets for Enhanced Electrochemical Performance in Supercapacitors and the Oxygen Evolution Reaction

Scalable Construction of Gel-like g-C3N4 Nanosheet Hybrids as High-Performance Water-Based Additives

Scalable Construction of Gel-like <i>g</i>-C₃N₄ Nanosheet Hybrids as High-Performance Water-Based Additives

Oxalic Acid-Assisted Vacancy Engineering Promotes Iron-Copper Sulfide Nanosheets for High-Current Density Water Oxidation.

The effective defect and interface coupling are pivotal for the promotion of the catalytic activity for the oxygen evolution reaction. Herein, we report novel hybrid nanosheets with sulfur vacancies composed of FeS2 and Cu39S28 grown on Cu foam (Vs-FeS2/Cu39S28). The optimal Vs-FeS2/Cu39S28 exhibits a high current output of 500 mA cm-2 at a low overpotential of 370 mV and robust stability for 60 h at 100 mA cm-2, surpassing the values of most previously reported Cu-based catalysts. Furthermore, a two-electrode electrolyzer made by pairing the prepared catalyst with commercial Pt/C requires a low cell voltage of 1.75 V at 100 mA cm-2 and is retained over 80 h. Key to its excellent performance is the synergism between intertwined FeS2 and Cu39S28 domains, enriched by the deliberate introduction of sulfur vacancies, thus optimizing the electronic structure and causing the proliferation of catalytic active sites. This work presents a potent Cu-based electrocatalyst and emphasizes the leveraging of non-precious metals for efficient water oxidation.

Surface modification of GO/PVDF composite membrane by MXene/protonated g‐C₃N₄ nanosheets hybrids with improved dye separation and antifouling properties

AbstractGraphene oxide‐polyvinylidene composite membranes were fabricated via the phase inversion technique. Then, GO‐PVDF membrane with highest water flux was achieved via surface modification with 2‐D MXene and 2‐D MXene /protonated 2‐D g‐C₃N₄ nanosheets hybrid via vacuum filtration of an aqueous dispersion of MXene and MXene‐protonated g‐C₃N₄ nanosheets hybrid, respectively, on GO‐PVDF membrane support to improve filtration efficiency and antifouling properties. The membranes were designated as MXene/GO‐PVDF (M2) and MXene‐protonated g‐C₃N₄/GO‐PVDF(M3). XRD, SEM, and FTIR analysis were used for characterization. The results showed that the performance of both MXene /GO‐PVDF and MXene‐ Pg‐C₃N₄/GO‐PVDF membranes was improved significantly in removing cationic dyes, unlike anionic pigments. Also, the resistance of these membranes against fouling has improved. The MXene‐ Pg‐C₃N₄/GO‐PVDF shows a significant enhancement in the removal of crystal violet (CV) cationic dye (100%) compared to the pristine membrane (84%) after 4 h of the filtration process. Tests also were performed to remove another two cationic dyes Methylene blue (MB), Rhodamine B (RB), and an anionic dye Methyl‐orange. The anionic dye separation rate from the stream did not show significant improvement while cationic dyes show significant enhancement in separation efficiencies. Modified membranes exhibit an enhancement of fouling resistance properties compared to pristine membranes.Highlights The water contact angle decreased from 71 to 45, which means hydrophilicity improved successfully. Membrane fouling resistance was improved around 15%–20%. PVDF membrane was prepared and graphene oxide was added to the matrix to modify the bulk properties. MXene and C3N4 were synthesized successfully. Surface modification of the PVDF membrane was successful by MXene and C3N4.

Assembling highly efficient X-ray and UV-visible light detectors using a VS2–MoS2 and VS2–WS2 hybrid composite-embedded perovskite layer

A facile hydrothermal reaction was employed to form VS2–XS2 hybrid nanosheets. Superior photoresponsivity and X-ray sensitivity were realized by the photodetectors composed of Cs0.1MA0.9PbI3-VS2–WS2.

Two-dimensional covalent organic framework-based hybrid nanosheets for electrochemical detection of 5-fluorouracil and uracil in biofluids

A 2D covalent organic framework (COF), supramolecule cucurbit[8]uril, and an AuNP-based electrochemical sensor for simultaneous detection of 5-fluorouracil and uracil, in concentrated biofluids, holding promise for practical sensing.

1D hollow tubular/2D nanosheet hybrid dimensional porous carbon prepared by one-step carbonization using natural minerals as templates for supercapacitors.

The reasonable construction of one-dimensional (1D)/two-dimensional (2D) hybrid dimensional porous carbon materials with complementary advantages and disadvantages is an important approach to addressing the structural and performance deficiencies of single carbon materials, while also significantly improving the electrochemical performance of super-capacitors. In this study, 1D hollow tubular/2D nanosheet hybrid dimensional porous carbon was synthesized through one-step carbonization using 1D fibrous brucite and 2D layered magnesium carbonate hydroxide as templates. By adjusting the feed ratio of 1D fibrous and 2D layered templates, the morphology, pore structure and specific surface area (SSA) of the prepared 1D hollow tubular/2D nanosheet hybrid dimensional porous carbon were controlled. The prepared hybrid dimensional porous carbons were characterized using scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and nitrogen adsorption-desorption. And their electrochemical performance was also studied by cyclic voltammograms (CV), galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS). The results show that the use of templates with different dimensions significantly influences the morphology, pore structure, SSA and electrochemical performance of the synthesized hybrid dimensional porous carbon. The hybrid dimensional porous carbon (3F) exhibits a high specific capacitance and excellent cycling stability. 3F demonstrates the specific capacitance of 245.3 F g-1 at 1 A g-1. Furthermore, the capacity retention rate remains as high as 93.4% after 8000 cycles at 10 A g-1. This work reveals that hybrid dimensional porous carbon composed of 1D hollow carbon tubes and 2D carbon nanosheets has great potential for use in supercapacitor electrode materials.

A Grafted Hybrid Nanosheet Array Architecture Enables Efficient Bifunctional Oxygen Catalytic Electrodes for Rechargeable Lithium−Oxygen Batteries

AbstractTo fully manifest the high energy densities of lithium−oxygen (Li−O2) batteries, bifunctional catalytic cathodes that efficiently facilitate both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) are mandatorily required. However, catalysts with intrinsic bifunctional catalytic activities are limited in practice. In addition, the practical utilization rate of oxygen catalytic cathodes is usually lower due to the deposition of insoluble discharge product Li2O2. To address these issues, this work proposes a grafted hybrid nanosheet array architecture to enable efficient bifunctional oxygen catalytic cathodes for Li−O2 batteries. As a demonstration, Co3O4 nanosheet arrays (MnO2−Co3O4@CC) grafted with MnO2 nanosheets are prepared on carbon cloth by facile electrodeposition followed by calcination in air. The mutually perpendicular Co3O4 and MnO2 nanosheets in the grafted architecture enable both the ORR catalytically active site of MnO2 and the OER catalytically active site of Co3O4 easily accessible during repeated cycling. Thus, the synergistic bifunctional catalysis of hybrid MnO2−Co3O4@CC is effectively realized to deliver a high specific capacity of 8115 mA h g−1 and a low overall overpotential of 0.64 V. This work provides a universal and effective approach for fabricating various efficient catalytic electrodes via the facile integration of different nanomaterials on nanoarray architectures.

An ultra-stable and sensitive Ag-HP-β-CD/GO/NCF SERS substrate combine with the coffee-ring effect strategy for trace PAHs detection

This study proposes an ultra-stable and highly sensitive SERS substrate based on Ag nanoparticles/graphene oxide nanosheets hybrids decorated nanocellulose fiber (Ag/GO/NCF), which was further functionalized with hydroxypropyl-β-cyclodextrin (Ag-HP-β-CD/GO/NCF) for the trace detection of polycyclic aromatic hydrocarbons (PAHs). The Ag/GO hybrid structure enables the substrate to exhibit high SERS activity through the synergistic effect of electromagnetic and chemical enhancement. Simultaneously, the three-dimensional skeleton structure of NCF serves as a support matrix, ensuring the exceptional stability of the substrate. Furthermore, this study introduces a SERS measurement strategy utilizing the coffee-ring effect and explores parameters optimization to further enhance the detection sensitivity while maintaining the homogeneity and reproducibility. With the affinity effect of HP-β-CD and the enrichment effect of the delocalized π-electron system in GO, the hydrophobic PAHs could easily approach the SERS hotspots and achieve their trace detection. The limit of detection (LOD) for four representative PAHs, including pyrene, fluoranthene, phenanthrene and fluorene, are found to be 3.32 ug/L, 3.65 ug/L, 40.97 ug/L and 56.24 ug/L, respectively. These results highlight the potential application of this highly efficient SERS platform in environmental monitoring.

In Situ Metal-Oxygen-Hydrogen Modified B-Tio2 @Co2 P-X S-Scheme Heterojunction Effectively Enhanced Charge Separation for Photo-assisted Uranium Reduction.

Photo-assisted uranium reduction from uranium mine wastewater is expected to overcome the competition between impurity ions and U(VI) in the traditional process. Here, B-TiO2 @Co2 P-X S-scheme heterojunction with metal-oxygen-hydrogen (M-O-H) is developed insitu modification for photo-assisted U(VI) (hexavalent uranium) reduction. Relying on the DFT calculation and Hard-Soft-Acid-Base (HSAB) theory, the introduction of metal-oxygen-hydrogen (M-O-H, hard base) metallic bonds in the B-TiO2 @Co2 P-X is found to enhance the hydrophilicity and the capture capability for uranyl ion (hard acid). Accordingly, B-TiO2 @Co2 P-500 hybrid nanosheets exhibit excellent U(VI) reduction ability (>98%) in the presence of competing ions. By self-consistent energy band calculations and in-situ KPFM spectral analysis, the formation of the internal electric field between B-TiO2 and Co2 P at the heterojunction is proven, offering a strong driving force and atomic transportation highway for accelerating the S-scheme charge carriers directed migration and promoting the photocatalytic reduction of uranium. This work provides a valuable route to explore the functionally modified photocatalyst with high-efficiency photoelectron separation for U(VI) reduction.

Constructing In2S3/CdS/N-rGO Hybrid Nanosheets via One-Pot Pyrolysis for Boosting and Stabilizing Visible Light-Driven Hydrogen Evolution

The construction of hybrid junctions remains challenging for the rational design of visible light-driven photocatalysts. Herein, In2S3/CdS/N-rGO hybrid nanosheets were successfully prepared via a one-step pyrolysis method using deep eutectic solvents as precursors. Benefiting from the surfactant-free pyrolysis method, the obtained ultrathin hybrid nanosheets assemble into stable three-dimensional self-standing superstructures. The tremella-like structure of hybrid In2S3/N-rGO exhibits excellent photocatalytic hydrogen production performance. The hydrogen evolution rate is 10.9 mmol·g−1·h−1, which is greatly superior to CdS/N-rGO (3.7 mmol·g−1·h−1) and In2S3/N-rGO (2.6 mmol·g−1·h−1). This work provides more opportunities for the rational design and fabrication of hybrid ultrathin nanosheets for broad catalytic applications in sustainable energy and the environment.

Interlayer Engineering of VS2 Nanosheets via In Situ Aniline Intercalative Polymerization toward Long-Cycling Magnesium-Ion Batteries.

Rechargeable magnesium batteries (RMBs) show great potential in large-scale energy storage systems, due to Mg2+ with high polarity leading to strong interactions within the cathode lattice, and the limited discovery of functional cathode materials with rapid kinetics of Mg2+ diffusion and desirable cyclability retards their development. Herein, we innovatively report the confined synthesis of VS2/polyaniline (VS2/PANI) hybrid nanosheets. The VS2/PANI hybrids with expanded interlayer spacing are successfully prepared through the exfoliation of VS2 and in situ polymerization between VS2 nanosheets and aniline. The intercalated PANI increases the interlayer spacing of VS2 from 0.57 to 0.95 nm and improves its electronic conductivity, leading to rapid Mg-ion diffusivity of 10-10-10-12 cm2 s-1. Besides, the PANI sandwiched between layers of VS2 is conducive to maintaining the structural integrity of electrode materials. Benefiting from the above advantages, the VS2/PANI-1 hybrids present remarkable performance for Mg2+ storage, showing high reversible discharge capacity (245 mA h g-1 at 100 mA g-1) and impressive long lifespan (91 mA h g-1 after 2000 cycles at 500 mA g-1). This work provides new perspectives for designing high-performance cathode materials based on layered materials for RMBs.

Interfacial engineering of hierarchical MoNi4/NiO heterostructure nanosheet arrays as bifunctional electrocatalysts for urea-assisted energy-saving hydrogen production

Employing urea oxidation reaction (UOR) to substitute slow oxygen evolution reaction (OER) is an effective technique to accomplish high-efficiency hydrogen production. The exploitation of inexpensive and highly active bifunctional catalyst still remains a considerable challenge. We report the hybrid nanosheet arrays constructed of MoNi4/NiO heterojunction with hierarchically crosslinked network architecture by hydrothermal reaction and subsequent annealing process under H2/Ar atmosphere. The special heterostructure with neoteric morphology can promote electron shift and interface interaction through the powerful coupling interface between MoNi4 and NiO, increasing charge transfer speed, intrinsic activity and electrolyte transport. Only 31 mV overpotential and 1.37 V potential are needed to arrive 10 mA cm−2 for hydrogen evolution reaction (HER) and UOR, respectively. For the two-electrode urea-assisted electrolyzer, the lower potential of 1.41 V is required to reach 10 mA cm−2. Moreover, it displays superior stability with unceasing working for 54 h at the cell voltage of 1.41 V without obvious activity degeneration. This research provides an insight on the construct of high-efficiently bifunctional catalyst by synergistic coupling of NiMo-based alloys with metal oxides.

Determination of Cholesterol by Colorimetry and Surface-Enhanced Raman Spectroscopy Using Gold Nanoparticles Decorated with a Fe(III)-Tetra(4-Carboxyphenyl)-Porphine Metal-Organic Framework

A simple and facile hydrothermal method was developed for the synthesis of gold nanoparticles (AuNPs) adorned with two-dimensional (2D) heme-like Fe(III)-tetra(4-carboxyphenyl)-porphine (TCPP-Fe) metal-organic framework (MOF) nanocomposite. Notably, the synthesized hybrid nanomaterial (AuNPs/TCPP-Fe hybrid nanosheets) exhibited excellent peroxidase (POD)-like nanoenzymes activity and Raman activity under ultrasound (US) and near-infrared (NIR) irradiation at physiological pH conditions. A cascade colorimetric-SERS dual-mode method was developed for sensitive and rapid cholesterol determination based on the excellent POD-like properties and surface-enhanced Raman spectroscopy (SERS) activity of AuNPs/TCPP-Fe nanoenzymes. The TCPP-Fe nanoenzymes combined with cholesterol oxidase catalyze a cascade reaction to convert cholesterol to H2O2, which then oxidizes colorless, low Raman-activity 3,3′,5,5′-tetramethylbenzidine (TMB) to a blue, high-Raman-activity oxidation product (ox-TMB). The cholesterol in human serum of colorimetric-SERS was successfully assayed with good recovery from 97.8 to 103.7%. The study paves a new method for designing a nanocomposite-based SERS for biochemistry analysis.

In situ synthesis copper phosphate-protein hybrid nanoflower on nickel foam for the sensitive detection of glucose in body fluids

We have synthesized copper phosphate-protein hybrid heterostructure nanoflowers (Cu(II)-HNFs) in situ on nickel foam for the first time. The interaction between protein and copper ions facilitated the nucleation growth of copper phosphate crystals and self-assembly of hybrid nanosheets into exquisite flower-like nanostructures. The unique high-specific surface structure of Cu(II)-HNFs provided high-density catalytically active sites for copper phosphate. Also, the direct growth of Cu(II)-HNFs on the NiF surface enhanced the electron transfer efficiency during catalysis. As a result, Cu(II)-HNFs exhibit an excellent electrocatalytic efficacy in glucose sensing. Including wide linear range of 0.1-3000 μM, high sensitivity of 2497.1 μA mM−1 cm−2, ultra-low detection limit of 0.03 μM, good selectivity, and stability. Moreover, Cu(II)-HNFs@NiF has been validated as a reliable tool for detecting glucose in urine samples, with recoveries ranging from 92.9 % to 101.9 %. These findings demonstrate that the developed Cu(II)-HNFs@NiF has immense potential for non-invasive glucose monitoring through body fluids.

Stacked ZnS multilayers of ZnS(en)0.5 hybrids with enhancing photocatalytic performance for H2 production

Zinc sulfide hybrids with different stacked ZnS multilayers were prepared using a chemical precipitation method in a solvent mixture of Ethylenediamine:Water:Butanol via two routes - nitrate and acetate salt precursors. The impact of butanol solvent contents (30 and 60 vol%) on the formation of orthorhombic-ZnS(en)0.5 hybrid with different stacking of ZnS layers was comprehensively analyzed using X-ray diffraction, Fourier Transform Infrared, X-ray photoelectron spectroscopy, and diffuse reflectance spectroscopy. Scanning electron microscopy was employed to study the influence of the mixture solvent on particle size and morphology of the resulting ZnS(en)0.5 hybrid micro flakes or nanosheets. The photocatalytic response was evaluated through hydrogen production reactions using low photocatalyst load under UV light irradiation, conducted over four reaction cycles. A significant increase in hydrogen production rate (4.6 and 4.0 times more active) was achieved for the exfoliated ultrathin nanosheet ZnS(en)0.5 hybrid prepared with lower butanol contents from the nitrate and acetate route, respectively. This enhancement was attributed to the reduced size of the nanosheets of stacked ZnS multilayers, which resulted from the incorporation of 30 vol% of butanol during the synthesis. Overall, the findings indicate that the Ethylenediamine:Butanol solvent system plays a crucial role in tuning the degree of ZnS stacking layers, the particle size, and morphology of ZnS(en)0.5 hybrids, leading to improved photocatalytic performance in hydrogen production reactions.

Enhancement of the thermal conductivity of a near room temperature magnetocaloric composite using graphene-like hybrid nanosheets derived from organic waste

Polymer matrix composites, fabricated to counter the inherent brittleness of magnetocaloric Heusler alloys, suffer from low thermal conductivity. Here, we demonstrate a low-cost, scalable route towards developing thermally conductive, mechanically robust near-room-temperature magnetocaloric composites by incorporating graphene-like hybrid nanostructures chemically synthesized from discarded sugarcane. Micron-sized particles obtained by manually grinding Ni50.2Mn36.7Sn13 ribbons possessing a strong magnetostructural transformation near room-temperature were chosen as the active magnetocaloric fillers. Both the functional fillers were incorporated into a polysulfone matrix by solution casting. Large values of isothermal entropy change ∼ 0.43 and -0.46 J/kg.K were observed for a ΔH = 2T, driven by two successive first and second-order transformations within the alloy fillers. Additionally, an enhanced value of the in-plane thermal conductivity ∼ 3.06 ± 0.4 W/m.K was observed in the composites owing to the formation of efficient thermal bridges/pathways by the graphene-like hybrid nanostructures, rendering them promising candidates for magnetic refrigeration applications.

Engineering the novel two-dimensional MoCoFe hybrid nanoarray electrodes derived from metal-organic frameworks for highly efficient electrocatalytic oxygen evolution

The serious concern about energy shortage and environmental pollution requires the development of next-generation energy storage and conversion equipment. People have made tremendous efforts in developing alternative electrode materials (like metal oxides, hydroxides, or their compound materials) for water electrolysis. Among them, polymetallic organic framework nanostructures have attracted much attention. Metal-organic frameworks (MOFs) have undergone a topological transformation and surface reconstruction, and the multi-metal coupling effect could significantly improve the performance of oxygen evolution reaction (OER), providing another way to obtain effective catalysts. In this study, a highly active two-dimensional (2D) MoCoFe hybrid nanosheets derived from MOFs (MoCoFe@NC) was prepared as an electrocatalyst for OER. Given the synergistic effect between 2D nanosheet structure and polymetallic electronic modification, it provides highly dispersed and accessible active sites for electrochemical reactions. At the same time, nitrogen doping and the formation of metal sulfide hybrid products on the carbon substrate improve the conductivity, showing the potential of bifunctional electrocatalysts. In alkaline electrolytes, the electrocatalyst reveals an initial potential of 1.45 V and only requires an overpotential of 285 mV to reach a current density of 10 mA cm−2 and has good endurance. It still exhibits excellent activity after continuous operation for 20,000 s. These findings not only contribute theoretical support to the correlation between polymetallic coordination structure evolution and OER catalytic activity in compound materials but also offer prospects for the development of hybrid electrocatalysts.

Accordion-like polyoxometalate hybrid architectures for capacity-dense and flexible Zn-Ion battery cathodes

Polyoxometalates (POMs) have received significant attention as functional materials owing to their tunable structures and sizes, versatile electronic properties, and multiple electrochemical redox behaviours. However, the hierarchical architecture of POMs and their unique Zn storage mechanism have yet to be explored for Zn-ion battery (ZIB) applications. Herein, we demonstrate an accordion-like hierarchical architecture of POM-based hybrids (L-rGO/PPy@POM) via a redox-relay Heck reaction, where multi-layered reduced graphene oxide (rGO)/polypyrrole (PPy) hybrid nanosheets are assembled with ultrafine POM nanoparticles through specific interaction. As confirmed through in situ and ex situ spectroscopic methods, the Mo=O bond is more implicated in Zn2+ insertion than the two Mo–O single bonds and two edge-sharing and corner-sharing Mo–Mo bonds. Owing to a fast and facile redox kinetics, the ZIB cells with l-rGO/PPy@POM delivered high specific capacity of 269.3 mAh g−1 at 100 mA g−1, high-rate capacity of 68.0 mAh g−1 at 10,000 mA g−1, and 80.4% of capacity retention over 22,000 cycles in water-in-bisalt electrolytes. Furthermore, flexible quasi-solid-state ZIB full cells with l-rGO/PPy@POM cathode achieved the maximum volumetric energy and power densities of 51.1 mWh cmcell−3 and 1159.9 mW cmcell−3, demonstrating long-term cyclic stability and functional operation of various electronic devices.

Synergistic photocatalytic nanozymes to promote contaminant removal and hydrogen production

Photocatalytic nanozymes, which combine light-induced redox reactions and enzyme-like catalysis, have emerged as a promising class of nanomaterials. This alliance offers tremendous potential for light-enhanced enzyme-like activity and expands the applications of nanozymes in energy and environmental fields. In this study, a photocatalytic nanozyme OVs-TiO2/Pd hybrid nanosheets (HNSs) with abundant oxygen vacancies (OVs) and controllable Pd components was prepared by a one-step solid-phase reduction method. Benefiting from the synergistic effect and the strong metal-support interaction, OVs-TiO2/Pd HNSs exhibit remarkable light-enhanced oxidase-like and hydrogenase-like activity, they efficiently catalyze the degradation of antibiotics and the production of hydrogen, respectively. Electron spin resonance and transient photovoltage techniques elucidated that the enhanced enzyme-like activities are attributed to the increased generation of charge carriers and reactive oxygen species. This study builds a bridge between photocatalysis and enzyme-like catalysis, opening up a new avenue to explore the multiple functional nanomaterials for a myriad of applications.