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1.
J Colloid Interface Sci ; 677(Pt A): 1005-1015, 2025 Jan.
Article in English | MEDLINE | ID: mdl-39128284

ABSTRACT

Heterostructures endow electrochemical hybrids with promising energy storage properties owing to synergistic effects and interfacial interaction. However, developing a facile but effective approach to maximize interface effects is crucial but challenging. Herein, a bimetallic sulfide/carbon heterostructure is realized in a confined carbon network via a high-throughput template-assisted strategy to induce highly active and stable electrode architecture. The designed heterostructures not only yield abundant interconnected Co9S8/MoS2/N-doped carbon (Co9S8/MoS2/NC) heterojunctions with continuous channels for ion/electron transfer but maintain excellent conversion reversibility. Serving as anode for sodium storage, the Co9S8/MoS2/NC framework displayed excellent sodium storage properties (reversible capacity of 480 mAh/g after 100 cycles at 0.2 A/g and 286.2 mAh/g after 500 cycles at 2 A/g). Given this, this study can guide future design protocols for interface engineering by forming dynamic channels of conversion reaction kinetics for potential applications in high-performance electrodes.

2.
J Colloid Interface Sci ; 677(Pt A): 974-982, 2025 Jan.
Article in English | MEDLINE | ID: mdl-39128291

ABSTRACT

Heterostructures and the introduction of heterogeneous elements have been regarded as effective strategies to promote electrochemical performance. Herein, sulfur species are introduced by a simple hydrothermal vulcanization method, which constructs the open heterostructure Fe7S8/Mn(OH)2 as a bifunctional material. The open cordyceps-like morphology can make the material contact more sufficiently with the electrolyte, exposing a large number of reaction sites. Furthermore, the introduction of the heterogeneous element S successfully constructs a heterogeneous interface, the interface-modulated composite material consists of Mn atoms contributing the main density of states (DOS) near the Fermi energy level from the density functional theory (DFT) calculations, which optimizes the adsorption energy of oxygen-containing intermediates during the oxygen evolution reaction (OER) process and reduces the reaction energy barrier, being conducive to the improvement of the material's electrochemical properties. As predicted, the Fe7S8/Mn(OH)2 material exhibits remarkable electrochemical properties, such as an overpotential of 202 mV at 10 mA cm-2 for the oxygen evolution reaction and even a specific capacitance of 2198 F g-1 at 1 A g-1. This work provides new insights into the role of introducing sulfur species and controlling the structure of the material, and exemplifies novel design ideas for developing bifunctional materials for energy storage and conversion.

3.
J Colloid Interface Sci ; 677(Pt A): 1069-1079, 2025 Jan.
Article in English | MEDLINE | ID: mdl-39137609

ABSTRACT

Designing inexpensive, high-efficiency and durable bifunctional catalysts for urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) is an encouraging tactic to produce hydrogen with reduced energy expenditure. Herein, oxygen vacancy-rich cobalt hydroxide/aluminum oxyhydroxide heterostructure on nickel foam (denoted as Co(OH)2/AlOOH/NF-100) has been fabricated using one step hydrothermal process. Theoretical calculation and experimental results indicate the electrons transfer from Co(OH)2 to highly active AlOOH results in the interfacial charge redistribution and optimization of electronic structure. Abundant oxygen vacancies in the heterostructure could improve the conductivity and simultaneously serve as the active sites for catalytic reaction. Consequently, the optimal Co(OH)2/AlOOH/NF-100 demonstrates excellent electrocatalytic performance for HER (62.9 mV@10 mA cm-2) and UOR (1.36 V@10 mA cm-2) due to the synergy between heterointerface and oxygen vacancies. Additionally, the in situ electrochemical impedance spectrum (EIS) for UOR suggests that the heterostructured catalyst exhibits rapid reaction kinetics, mass transfer and current response. Importantly, the urea-assisted electrolysis composed of the Co(OH)2/AlOOH/NF-100 manifests a low cell voltage (1.48 V @ 10 mA cm-2) in 1 M KOH containing 0.5 M urea. This work presents a promising avenue to the development of HER/UOR bifunctional electrocatalysts.

4.
J Colloid Interface Sci ; 677(Pt B): 140-150, 2025 Jan.
Article in English | MEDLINE | ID: mdl-39142155

ABSTRACT

The explorations of efficient electrocatalysts to accelerate oxygen reactions in a wide temperature range is a crucial issue to the development of zinc-air batteries (ZAB) for all-climate applications. Herein, the Co-CoSe heterogeneous furry fibers (Co-CoSe@NHF) are developed as a bifunctional oxygen electrocatalyst for ZAB towards wide-temperature range applications. The Co-CoSe heterostructure with large work function difference (ΔWF) endows interfacial electron redistribution, which builds strong interfacial built-in electric field (BIEF) and improves the oxygen reactions. Meanwhile, the Co-CoSe heterostructure is encapsulated by in-situ grown carbon nanotubes, and forms the hollow fiber (NHF) with furry surface and beads-on-string configuration. The highly porous and conductive NHF configuration facilitates the fast kinetics and favors to accommodates volume change during cycling. As a result, the Co-CoSe@NHF achieves the superior bifunctional properties and good reliability for oxygen reactions. Integrated with the Co-CoSe@NHF fiber, the ZAB cell delivers the superior power density (301 mW cm-2) and long-term cycling stability over 280 h at 25 °C, and maintains the power densities of 126 mW cm-2 even the temperature decreases to -25 °C. Moreover, the solid-state ZAB exhibits significant flexibility and superior properties in a wide temperature range. Therefore, this work not only proposes a new strategy to design the high-performance bifunctional electrocatalysts, but also propels the development of flexible power sources for all-climate applications.

5.
J Colloid Interface Sci ; 677(Pt B): 541-550, 2025 Jan.
Article in English | MEDLINE | ID: mdl-39154446

ABSTRACT

The advancement of interface engineering has demonstrated remarkable efficacy in overcoming the primary impediment associated with sluggish reaction kinetics in supercapacitor electrodes. In this investigation, we employed a facile co-precipitation method to synthesize NiCoMoO4/MXene heterostructures utilizing Ti3C2Tx MXene nanosheets as carriers. This heterostructure inhibits the restacking of MXene nanosheets and simultaneously enhances the exposure of electrochemically active sites in NiCoMoO4 nanorods, thereby mitigating the reduction in specific capacitance resulting from volumetric fluctuations. The NiCoMoO4/MXene electrode, possessing pseudo-capacitance properties, demonstrates an impressive level of specific capacitance, exceptional performance across various charging rates, and consistent behavior throughout repeated cycles. By optimizing the mass ratio, this electrode achieves a specific capacity of 1900 F/g under a current density of 1 A/g. Even after enduring 10,000 cycles at a significantly higher current density of 5 A/g, it still maintains an impressive retention rate of 94.73 %. Our density functional theory (DFT) calculations indicate that the enhanced electrochemical performance can be attributed to the improved electronic coupling within the NiCoMoO4/MXene heterostructure. The integration of NiCoMoO4/MXene cathode and activated carbon (AC) anode with an alkaline gel electrolyte containing potassium ferricyanide in flexible quasi-solid-state supercapacitors (FSSCs) results in exceptional electrochemical performance and flexibility. These FSSCs demonstrate a maximum energy density of 72.89 Wh kg-1 at a power density of 850 W kg-1, while maintaining an impressive power output of 16,780 W kg-1 with an energy density of 37.28 Wh kg-1. Based on these outstanding properties, it is evident that the NiCoMoO4/MXene heterojunction possesses significant advantages as electrode material for supercapacitors, and the fabricated FSSCs devices pave a new pathway for flexible electronic devices.

6.
J Colloid Interface Sci ; 677(Pt B): 804-815, 2025 Jan.
Article in English | MEDLINE | ID: mdl-39173513

ABSTRACT

Carbon aerogel has gained intense attention as one of the most promising microwave absorption materials. It can overcome severe electromagnetic pollution, thanks to its 3D macroscopic structure and superb conductive loss capacity. However, there is still a big challenge to endow multifunctionality to carbon aerogel while maintaining its good electromagnetic wave absorption (EWA) so as to adapt wide practical application. Herein, a novel carbon-based aerogel consisting of Cu and TiO2 nanoparticles dispersed on carbon nanofiber framework was derived from carbonized bacterial cellulose (CBC) decorated with its mother bacteria via freeze-drying, in situ growth and carbonization strategies. The synthesized carbon-based CBC/Cu/TiO2 aerogel achieved an excellent EWA performance with a broad effective absorption bandwidth (EAB) of 8.32 GHz. It is attributed to the synergistic loss mechanism from multiple scattering, conductive network loss, interfacial polarization loss and dipolar polarization relaxation. Meanwhile, the obtained aerogel also shows an excellent thermal insulation with a 3-mm-thick sample generating a temperature gradient of over 42 °C at 85 °C and a maximum radar cross-section (RCS) reduction of 23.88 dB m2 owing to the cellular structure and synergistic effects of multi-components. Therefore, this study proposes a feasible design approach for creating lightweight, effective, and multifunctional CBC-based EWA materials, which offer a new platform to develop ultrabroad electromagnetic wave absorber under the guidance of RCS simulation.


Subject(s)
Carbon , Cellulose , Gels , Microwaves , Titanium , Cellulose/chemistry , Carbon/chemistry , Gels/chemistry , Titanium/chemistry , Copper/chemistry , Particle Size , Surface Properties
7.
J Environ Sci (China) ; 149: 221-233, 2025 Mar.
Article in English | MEDLINE | ID: mdl-39181637

ABSTRACT

Catalytic reduction of nitrate over bimetallic catalysts has emerged as a technology for sustainable treatment of nitrate-containing groundwater. However, the structure of bimetallic has been much less investigated for catalyst optimization. Herein, two main types of Pd-Cu bimetallic nanocrystal structures, heterostructure and intermetallic, were prepared and characterized using high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results show that two individual Pd and Cu nanocrystals with a mixed interface exist in the heterostructure nanocrystals, while Pd and Cu atoms are uniformly distributed across the intermetallic Pd-Cu nanocrystals. The catalytic nitrate reduction experiments were carried out in a semibatch reactor under constant hydrogen flow. The nitrate conversion rate of the heterostructure Pd-Cu nanocrystals supported on α-Al2O3, γ-Al2O3, SBA-15, and XC-72R exhibited 3.82-, 6.76-, 4.28-, 2.44-fold enhancements relative to the intermetallic nanocrystals, and the nitrogen and nitrite were the main products for the heterostructure and intermetallic Pd-Cu nanocrystals, respectively. This indicates that the catalytic nitrate reduction over Pd-Cu catalyst is sensitive to the bimetallic structures of the catalysts, and heterostructure bimetallic nanocrystals exhibit better catalytic performances on both the activity and selectivity, which may provide new insights into the design and optimization of catalysts to improve catalytic activity and selectivity for nitrate reduction in water.


Subject(s)
Copper , Nitrates , Oxidation-Reduction , Palladium , Catalysis , Copper/chemistry , Palladium/chemistry , Nitrates/chemistry , Metal Nanoparticles/chemistry , Nanoparticles/chemistry , Water Pollutants, Chemical/chemistry , Models, Chemical
8.
Small ; : e2407659, 2024 Sep 30.
Article in English | MEDLINE | ID: mdl-39350445

ABSTRACT

Photo-assisted electrocatalysis has arisen as a promising approach for hydrogen generation by incorporating photocatalysts into electrocatalysts. 2D SnS2 is a photocatalyst that absorbs visible light. However, the rapid recombination of photo-generated electron-hole pairs significantly reduces the overall photocatalytic efficiency of SnS2, limiting its practical application. Thus, this study prepares an in situ heterojunction SnS2@SnO2 using a one-step hydrothermal method. The degradation efficiency of methyl orange (MO) using SnS2@SnO2 is measured, achieving a degradation rate of 92.75% within 1 h, which is 1.9 times higher than that of pure SnS2. Additionally, FeNiS/SnS2@SnO2 is synthesized and exhibited significant improvements in the photo-assisted oxygen evolution reaction (OER). It achieves an overpotential of 260 mV and a Tafel slope of 65.1 mV dec-1 at 10 mA cm-2, showing reductions of 11.8% and 31.8%, respectively, compared to FeNiS alone. These enhancements highlight the strong photo-response capability of SnS2@SnO2. Under the internal electric field of SnS2@SnO2, the photogenerated electrons in the conduction band of SnS2 quickly move toward SnO2, facilitating efficient photocatalytic reactions. FeNiS, with a lower Fermi energy level (EF), facilitates electron transfer from SnS2@SnO2 and enhances OER performance by efficiently participating in the reaction. This study paves a new path for 2D photocatalyst materials.

9.
J Colloid Interface Sci ; 679(Pt A): 75-89, 2024 Sep 27.
Article in English | MEDLINE | ID: mdl-39357228

ABSTRACT

Transition metal alloys can exhibit synergistic intermetallic effects to obtain high activities for oxygen reduction/evolution reactions (ORR/OER). However, due to the insufficient stability of active sites in alkaline electrolytes, conventional alloy catalysts still do not meet practical needs. Herein, by using polypyrrole tubes and cobalt-iron (CoFe) Prussian blue analogs as precursors, CoFe sulfides is in-situ formed on CoFe alloys to construct (CoFe)(S2)2/CoFe heterostructure in sulfur (S) and nitrogen (N) co-doped carbon nanotubes (CoFe@NCNTs-nS) via a low-temperature sulfidation strategy. The as-marked CoFe@NCNTs-12.5S exhibits a comparable ORR activity (half-wave potential of 0.901 V) to Pt/C (0.903 V) and a superior OER activity (overpotential of 272 mV at 10 mA cm-2) to RuO2 (299 mV). CoFe@NCNTs-12.5S also exhibits ultralow charge transfer resistances (ORR-6.36 Ω and OER-0.21 Ω) and an excellent potential difference of 0.617 V. The sulfidation-induced (CoFe)(S2)2/CoFe heterojunctions can accelerate interfacial charge transfer process. Tubular structure not only disperses the (CoFe)(S2)2/CoFe heterostructure, but also reduces the corrosion of active-sites to enhance catalysis stability. Zinc-air battery with CoFe@NCNTs-12.5S achieves a high specific capacity (718.1 mAh g-1), maintaining a voltage gap of 0.957 V after 400 h. This work reveals the potential of interface engineering for boosting ORR/OER activities of alloys via in-situ heterogenization.

10.
Article in English | MEDLINE | ID: mdl-39357780

ABSTRACT

Heterostructures, such as van der Waals (vdW) heterostructures, provide a versatile platform for engineering the physical properties of two-dimensional (2D) layered materials, spanning electronics, mechanics, optics, as well as electron-phonon couplings. Furthermore, vdW heterostructures, which are composed of metal/semiconductor or semiconductor/semiconductor combinations, not only maintain the unique properties of their individual constituents but also exhibit tunable physical and chemical properties that can be externally adjusted through strain, heat, and electric fields. These externally tunable properties offer significant advances in the fields of solid-state devices and renewable energy applications. Additionally, 2D material-based heterostructures, such as those composed of 0D clusters or quantum dots, as well as 1D nanotubes/wires in combination with 2D materials, also show immense potential for advancing next-generation nanodevices. The vast design space of vdW heterostructures enables their versatile applications spanning numerous fields, such as light-emitting diodes, field-effect transistors, photocatalysis, solar cells, photodetectors, and so on. In the Special Issue of Journal of Physics: Condensed Matter, entitled "Two-dimensional Materials-based Heterostructures for Next-generation Nanodevices", we have gathered a comprehensive collection of 14 articles, presenting the latest achievements in the fields of designing novel 2D materials and 2D heterostructures. Below, we have briefly condensed the essential research findings from these studies. .

11.
Article in English | MEDLINE | ID: mdl-39361426

ABSTRACT

Heterostructures formed by transition metal dichalcogenides (TMDs) and two-dimensional layered halide perovskites (2D-LHPs) have attracted significant attention due to their unique optoelectronic properties. However, theoretical studies face challenges due to the large number of atoms and the need for lattice matching. With the discovery of more 2D-LHPs, there is an urgent need for methods to rapidly predict and screen TMDs/2D-LHPs heterostructures. This study employs first-principles calculations to perform high-throughput computations on 602 TMDs/2D-LHPs heterostructures. Results show that different combinations exhibit diverse band alignments, with MoS2 and WS2 more likely to form type-II heterostructures with 2D-LHPs. The highest photoelectric conversion efficiency of type-II structures reaches 23.26%, demonstrating potential applications in solar cells. Notably, some MoS2/2D-LHPs form type-S structures, showing promise in photocatalysis. Furthermore, we found that TMDs can significantly affect the conformation of organic molecules in 2D-LHPs, thus modulating the electronic properties of the heterostructures. To overcome computational cost limitations, we constructed a crystal graph convolutional neural network model based on the calculated data to predict the electronic properties of TMDs/2D-LHPs heterostructures. Using this model, we predicted the bandgaps and band alignment types of 9,360 TMDs/2D-LHPs heterostructures, providing a comprehensive theoretical reference for research in this field.

12.
Nano Lett ; 2024 Oct 03.
Article in English | MEDLINE | ID: mdl-39361493

ABSTRACT

Time reversal symmetry breaking in superconductors, resulting from external magnetic fields or spontaneous magnetization, often leads to unconventional superconducting properties. In this way, an intrinsic phenomenon called the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state may be realized by the Zeeman effect. Here, we construct the FFLO state in an artificial CrOCl/NbSe2 van der Waals (vdW) heterostructure by utilizing the superconducting proximity effect of NbSe2 flakes. The proximity-induced superconductivity demonstrates a considerably weak gap of about 0.12 meV, and the in-plane upper critical field reveals the behavior of the FFLO state. First-principles calculations uncover the origin of the proximitized superconductivity, which indicates the importance of Cr vacancies or line defects in CrOCl. Moreover, the FFLO state could be induced by the inherent large spin splitting in CrOCl. Our findings not only provide a practical scheme for constructing the FFLO state but also inspire the discovery of an exotic FFLO state in other two-dimensional vdW heterostructures.

13.
Nano Lett ; 2024 Oct 09.
Article in English | MEDLINE | ID: mdl-39382966

ABSTRACT

Some van der Waals (vdW) materials exhibit ferroelectricity, making them promising for novel nonvolatile memories (NVMs) such as ferroelectric diodes (FeDs). CuInP2S6 (CIPS) is a well-known vdW ferroelectric that has been integrated with graphene for memory devices. Here we demonstrate FeDs with self-rectifying, hysteretic current-voltage characteristics based on vertical heterostructures of 10 nm thick CIPS and graphene. By using vdW indium-cobalt top electrodes and graphene bottom electrodes, we achieve a high electroresistance (on- and off-state resistance ratios) of ∼106, an on-state rectification ratio of 2500 for read/write voltages of 2 V/0.5 V, and a maximum output current density of 100 A/cm2. These metrics compare favorably with state-of-the-art FeDs. Piezoresponse force microscopy measurements show that stabilization of intermediate net polarization states in CIPS leads to stable multibit data retention at room temperature. The combination of two-terminal design, multibit memory, and low-power operation in CIPS-based FeDs is potentially interesting for compute-in-memory and neuromorphic computing applications.

14.
J Colloid Interface Sci ; 679(Pt A): 578-585, 2024 Oct 05.
Article in English | MEDLINE | ID: mdl-39383836

ABSTRACT

The sluggish kinetics and inherent instability over the Ru/RuO2 clusters are still enormous challenges in proton exchange membrane (PEM) water electrolyzer. Herein, we innovatively report synergistic modulation of dynamic electron modification and strong metal-support interaction (SMSI) to activate and stabilize bifunctional fluorine doped Ru/RuO2 clusters anchored on carbon nanotube (CNT), thus achieving efficient and stable acidic overall water splitting. Theoretical and experimental studies found that surface metal-fluorine modification layer could dynamically regulate the interfacial electronic environment to stabilize and activate multiple active Ru species; and the SMSI between Ru/RuO2 cluster and CNT maintains stable electronic environment for dynamic electron modification and avoids migrating or shedding of active species in acidic environment. Therefore, the PEM electrolyzer assembled with optimal F5.5-Ru/RuO2@CNT can operate stably for 100 h at a high current density of 100 mA cm-2, which is the first time that bifunctional Ru-based nanocatalysts applied to PEM device at a high current density.

15.
Chemosphere ; : 143505, 2024 Oct 07.
Article in English | MEDLINE | ID: mdl-39384136

ABSTRACT

In this study, heterostructures based on Bismuth molybdite/iron oxide (Bi2MoO6/Fe2O3) thin films were fabricated by a dip-coating technique using precursor solutions. The heterostructures were deposited on fluorine-doped tin oxide glass substrates. From a detailed characterization using X-ray diffraction and X-ray photoelectron spectroscopy, the formation of the orthorhombic phase for Bi2MoO6 and the co-existence of hematite and maghemite in Fe2O3 was demonstrated. Meanwhile, the field emission scanning electron microscopy cross-section images confirm the formation of well-defined Bi2MoO6 film under the Fe2O3 deposition. The optical band gap energies for the heterostructure obtained were estimated from the diffuse reflectance spectra and ranged from 2.3 to 3.5 eV. Photoluminescence analysis revealed an improved separation and faster transfer of photogenerated electrons and holes for the Bi2MoO6/Fe2O3 (Het) film. The best oxytetracycline (OTC) removal percentage through photoelectrocatalytic treatment was 96.85% using the Het. Besides, were carried out the variation of parameters which affect the OTC photoelectrocatalytic degradation as pH, potential applied, and scavenger assay. The 1O2 was the oxidant predominate, which attack the OTC ring to initiate and accelerate the degradation process. Based on the analysis of degradation intermediates and characteristics of Bi2MoO6/Fe2O3, possible degradation pathways and mechanisms of OTC were displayed. An enhancement of oxytetracycline degradation efficiency of Het fabricated compared to pristine oxides was achieved mainly due to avoid the charge recombination of photogenerated electron-hole pairs provided by Direct Z-scheme heterostructure. Finally, the Het fabricated represents a promising material for efficient and sustainable pharmaceutical removal applications.

16.
J Colloid Interface Sci ; 679(Pt A): 420-429, 2024 Sep 21.
Article in English | MEDLINE | ID: mdl-39368161

ABSTRACT

How to achieve controllable preparation of heterostructure and in-situ optimize the interface and internal electron transfer by a fast and economic synthesis method has become a big challenge in the practical application of photocatalysis. Herein, an island-shaped SrTiO3 (STO) perovskite nanodots and TiO2 (T) compounded S-scheme SrTiO3/TiO2 (ST) heterostructure was successfully developed. During the millisecond reaction process, the decomposed Sr2+ penetrated into the TiO2 lattice causing the lattice expansion and inducing local atomic rearrangements, resulting in the generation of STO phase. Owing to the synergy of the efficient electron transport at the perovskite nanodots interface and the stronger reduction capacity, the performance of the optimized ST1 sample is greatly improved to 86.90 µmol g-1 for CO2-to-CO and 21.31 µmol g-1 for CO2-to-CH4. The utilization of electrons reached up to 119.74 µmol g-1 h-1, which was 3.13 times higher than that of T. Detailed characterizations and density functional theory (DFT) calculations proof that the formation of intermediates HCOO- and CO32- is the key to the performance improvement critically. Overall, this work originally reports a feasible strategy for flame synthesis of S-scheme heterostructure photocatalyst.

17.
Nanotechnology ; 2024 Oct 08.
Article in English | MEDLINE | ID: mdl-39378893

ABSTRACT

Using a first-principles approach, this study delves into the effects of strain and electrostatic doping on the electronic and magnetic properties of the GaN/VTe2van der Waals heterostructure. The results reveal that when the GaN/VTe2van der Waals heterostructure is doped with 0.1h/0.2hof electrostatic charge, its magnetization direction undergoes a remarkable reversal, shifting from out-of-plane orientation to in-plane direction. Therefore, we conduct a thorough investigation into the influence of electron orbitals on magnetic anisotropy energy. In addition, as the strain changes from -1% to 1%, the 100% spin polarization region of the GaN/VTe2vdW heterostructure becomes smaller. It is worth noting that at a doping concentration of 0.1h, the GaN/VTe2vdW heterostructure has a Curie temperature of 30 K above room temperature. This comprehensive study provides valuable insights and provides a reference for analyzing the electronic and magnetic properties of low-dimensional systems.

18.
Adv Mater ; : e2410186, 2024 Oct 09.
Article in English | MEDLINE | ID: mdl-39380425

ABSTRACT

The advancement of thin, lightweight, and high-power electronic devices has increasingly exacerbated issues related to electromagnetic interference and heat accumulation. To address these challenges, a spray-drying-sintering process is employed to assemble chain-like CoNi and flake boron nitride (BN) into hydrangea-like CoNi@BN heterostructure fillers. These fillers are then composited with polydimethylsiloxane (PDMS) to develop CoNi@BN/PDMS composites, which integrate low-frequency microwave absorption and thermal conductivity. When the volume fraction of CoNi@BN is 44 vol% and the mass ratio of CoNi to BN is 3:1, the CoNi@BN/PDMS composites exhibit optimal performance in both low-frequency microwave absorption and thermal conductivity. These composites achieve a minimum reflection loss of -49.9 dB and a low-frequency effective absorption bandwidth of 2.40 GHz (3.92-6.32 GHz) at a thickness of 4.4 mm, fully covering the n79 band (4.4-5.0 GHz) for 5G communications. Meanwhile, the in-plane thermal conductivity (λ∥) of the CoNi@BN/PDMS composites is 7.31 W m-1 K-1, which is ≈11.4 times of the λ∥ (0.64 W m-1 K-1) for pure PDMS, and 32% higher than that of the (CoNi/BN)/PDMS composites (5.52 W m-1 K-1) with the same volume fraction of CoNi and BN obtained through direct mixing.

19.
Small ; : e2405952, 2024 Oct 08.
Article in English | MEDLINE | ID: mdl-39377360

ABSTRACT

Enhancement of an alkaline water splitting reaction in Pt-based single-atom catalysts (SACs) relies on effective metal-support interactions. A Pt single atom (PtSA)-immobilized three-phased PtSA@VP-Ni3P-MoP heterostructure on nickel foam is presented, demonstrating high catalytic performance. The existence of PtSA on triphasic metal phosphides gives an outstanding performance toward overall water splitting. The PtSA@VP-Ni3P-MoP performs a low overpotential of 28 and 261 mV for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) at a current density of 10 and 25 mA cm-2, respectively. The PtSA@VP-Ni3P-MoP (+,-) alkaline electrolyzer achieves a minimum cell voltage of 1.48 V at a current density of 10 mA cm-2 for overall water splitting. Additionally, the electrocatalyst exhibits a substantial Faradaic yield of ≈98.12% for H2 and 98.47% for O2 at a current density of 50 mA cm-2. Consequently, this study establishes a connection for understanding the active role of single metal atoms in substrate configuration for catalytic performance. It also facilitates the successful synthesis of SACs, with a substantial loading on transition metal phosphides and maximal atomic utilization, providing more active sites and, thereby enhancing electrocatalytic activity.

20.
Small ; : e2406609, 2024 Sep 29.
Article in English | MEDLINE | ID: mdl-39344161

ABSTRACT

MoS2/ZnIn2S4 flower-like heterostructures into porous carbon (PC@MoS2/ZIS) are embedded. This ternary heterostructure demonstrates enhanced light absorption across a broad spectral range from 200 to 2500 nm. It features both Type-II and S-scheme dual heterojunction interfaces, which facilitate the generation, separation, and transfer of photoinduced carriers. The PC enveloped by MoS2/ZIS composite microspheres serves as a photothermal source, providing additional energy to the carriers. This process accelerates charge separation and migration, enhancing photothermal-assisted photocatalytic H2 evolution. The optimal H2 evolution rate for PC@MoS2/ZIS reaches an impressive 18.79 mmol g-1 h-1, with an apparent quantum efficiency of 14.1% at 400 nm. This work presents a promising approach for effectively integrating multicomponent heterostructures with photothermal effects, offering innovative strategies for efficient solar energy utilization and conversion.

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