Strong Coupling Effects Research Articles

Single-mode selection in a non-strongly coupled whispering gallery mode cavity

Mode selection through coupling multiple cavities has proven to be an effective method for constructing single-mode lasers. In coupled Fabry–Perot cavities, it is well accepted that mode selection relies on the strong coupling effect of closely contacted component structures. However, in coupled whispering gallery mode (WGM) cavities, the mode-selection mechanism remains under debate due to the inconsistent characteristics of the selected mode. Herein, we elucidate that the inconsistency can be attributed to varied selection mechanisms led by the trade-off between coupling strength and field distortion. Particularly, it is demonstrated that except for a traditional strong-coupling configuration, single-mode selection can also be achieved in an intermediate-coupling WGM configuration, where two component cavities depart from each other. This study addresses the gap in understanding mode selection in WGM cavity structures and explains the varied characteristics of single-mode lasing reported in the literature, thereby offering new insights into the development of miniaturized, low-threshold, single-mode laser devices.

Atomically Asymmetrical Ir-O-Co Sites Enable Efficient Chloride-mediated Ethylene Electrooxidation in Neutral Seawater.

The chloride-mediated ethylene oxidation reaction (EOR) of ethylene chlorohydrin (ECH) via electrocatalysis is practically attractive because of its sustainability and mild reaction conditions. However, the chlorine oxidation reaction (COR), which is essential for the above process, is commonly catalyzed by dimensionally stable anodes (DSAs) with high contents of precious Ru and/or Ir. The development of highly efficient COR electrocatalysts composed of nonprecious metals or decreased amounts of precious metals is highly desirable. Herein, we report a modified Co3O4 with a single-atom Ir substitution (Ir1/Co3O4) as a highly efficient COR electrocatalyst for chloride-mediated EOR to ECH in neutral seawater. Ir1/Co3O4 achieves a Faradaic efficiency (FE) of up to 94.8% for ECH generation and remarkable stability. Combining experimental results and density functional theory (DFT) calculations, the unique atomically asymmetrical Ir-O-Co configuration with a strong electron coupling effect in Ir1/Co3O4 can accelerate electron transfer to increase the reaction kinetics and maintain the structural stability of Co3O4 during COR. Moreover, a coupling reaction system integrating the anodic chloride-mediated and cathodic H2O2-mediated EOR show a total FE of ~170% for paired electrosynthesis of ECH and ethylene glycol (EG) using ethylene as the raw material. The technoeconomic analysis highlights the promising application prospects of this system.

Bifunctional MoO3-x/CuS Heterojunction Nanozyme-Driven "Turn-On" SERS Signal for the Sensitive Detection of Cerebral Infarction Biomarker S100B.

The use of nanozymes has become a promising auxiliary approach to "turn on" surface-enhanced Raman scattering (SERS) signals for the label-free detection of disease markers. Nevertheless, there are still major challenges to develop bifunctional nanomaterials with both excellent enzyme-like activity and high SERS performance. To this end, a novel Z-scheme MoO3-x/CuS heterojunction was first constructed as a powerful "two-in-one" substrate, which can not only catalyze leucomalachite green (LMG) to SERS-active malachite green (MG) but also serve as an efficient substrate to amplify the SERS signal of catalysate. Due to the strong interfacial coupling effect between the MoO3-x and CuS nanomaterial, which promoted the separation and transport of carriers in the heterojunction, the MoO3-x/CuS heterojunction showed higher peroxidase-like activity compared to individual components and the previously reported heterojunction nanozymes. Inspired by these results, a sandwich-type SERS immunoassay for the detection of the cerebral infarction biomarker S100 calcium-binding protein (S100B) was proposed based on the output signal of MG at 1620 cm-1. Furthermore, introducing the antifouling material chitosan on the surface of the MoO3-x/CuS heterojunction can effectively resist nonspecific protein adsorption and significantly improve the detection accuracy of the immunoassay. Therefore, the SERS immunoassay based on the MoO3-x/CuS heterojunction realized highly sensitive and selective detection of S100B in the concentration range of 0.001 to 100 ng/mL, with a low limit of detection of 0.47 pg/mL. The developed method has been successfully used for the accurate detection of S100B in clinical serum. The results showed that the level of S100B in the serum of cerebral infarction patients can be distinguished from those of healthy individuals and intracranial tumor patient controls. In addition, the acquired values of S100B in the serum of cerebral infarction patients based this strategy were well consistent with the results of electrochemiluminescence (ECL) detection with a relative error of less than ±7.3. It is expected that this work may open up a paradigm for improving detection sensitivity and accuracy for the early diagnosis and treatment monitoring of cerebral infarction in the clinic.

Atomically Asymmetrical Ir–O–Co Sites Enable Efficient Chloride‐mediated Ethylene Electrooxidation in Neutral Seawater

The chloride‐mediated ethylene oxidation reaction (EOR) of ethylene chlorohydrin (ECH) via electrocatalysis is practically attractive because of its sustainability and mild reaction conditions. However, the chlorine oxidation reaction (COR), which is essential for the above process, is commonly catalyzed by dimensionally stable anodes (DSAs) with high contents of precious Ru and/or Ir. The development of highly efficient COR electrocatalysts composed of nonprecious metals or decreased amounts of precious metals is highly desirable. Herein, we report a modified Co3O4 with a single‐atom Ir substitution (Ir1/Co3O4) as a highly efficient COR electrocatalyst for chloride‐mediated EOR to ECH in neutral seawater. Ir1/Co3O4 achieves a Faradaic efficiency (FE) of up to 94.8% for ECH generation and remarkable stability. Combining experimental results and density functional theory (DFT) calculations, the unique atomically asymmetrical Ir‐O‐Co configuration with a strong electron coupling effect in Ir1/Co3O4 can accelerate electron transfer to increase the reaction kinetics and maintain the structural stability of Co3O4 during COR. Moreover, a coupling reaction system integrating the anodic chloride‐mediated and cathodic H2O2‐mediated EOR show a total FE of ~170% for paired electrosynthesis of ECH and ethylene glycol (EG) using ethylene as the raw material. The technoeconomic analysis highlights the promising application prospects of this system.

Enhancement of NIR-II Emission of Er3+ by Doping Fe3+ in Double Perovskites: Multimode Luminescence for Versatile Optoelectronic Applications.

Erbium ions are commonly used to extend the photoelectric properties of metal halide perovskites from visible to near-infrared (NIR) range. However, achieving high-efficiency multi-mode luminescence in a single system is difficult due to the weak absorption associated with forbidden 4f-4f transitions. In this study, a unique strategy is proposed to adjust multi-mode luminescence and enhance NIR-II emission in Cs2NaBiCl6 by incorporating Fe3+ ions. The as-prepared material demonstrates reversible thermochromism, driven by strong electron-phonon coupling effect, and exhibits tunable luminescence that can be adjusted by altering excitation energy and temperature. Notably, benefitting from the charge transfer transition of Fe3+-Cl- along with the influence of Fe3+ doping on the geometrical and electronic structures, the blue-excitable (450 nm) NIR-II emission around 1541 nm from Er3+ is realized for the first time, achieving an intensity 16.7 times higher and a maximum photoluminescence quantum yield of 22.5%. This enhancement enables innovative applications such as two-dimensional information encryption by the multi-channel cooperative responses and improved NIR imaging. The study highlights the potential of Fe3+ doping in optimizing absorption and multi-mode luminescence in perovskites, opening avenues for advanced applications in blue-excitable NIR light emitting diodes, thermometer, anti-counterfeiting, and NIR imaging.

Rational design of MnCoGe alloys for enhanced magnetocaloric performance and reduced thermal hysteresis

MnCoGe alloys are widely recognized as an important family of rare-earth-free magnetocaloric materials by engineering its magnetostructural coupling for giant entropy changes. However, its practicability for magnetic refrigeration is largely hindered by the large thermal hysteresis. In this work, we show that the co-doped MnCoGe compound, namely Mn0.95Cu0.03CoGe with 2 both mol% Mn vacancies and 3 mol% Cu-doping for Mn, displays a maximum entropy change of 29.0 J kg-1K-1 at 295 K under a magnetic field of 5 T, together with a relative cooling power as high as 314.5 J kg-1 and a record low thermal hysteresis of 16 K. The co-doping strategy in MnCoGe finely tunes the structural transition temperature within the range of Curie temperature window, leading to a strong magnetostructural coupling and giant magnetocaloric effect. Meanwhile, Mn-deficiency and Cu-doping considerably reduce the energy difference between martensitic and austenitic MnCoGe, rendering a minimal thermal hysteresis. Our co-doped MnCoGe alloys are robust candidates for near-room-temperature magnetic refrigeration.

First-principles investigation of electronic, magnetic, and optical properties of FeMnSb/GaZ (Z = As or P) interfaces

We systematically investigated the electronic, magnetic, and optical properties of the FeMnSb half-Heusler alloy, its (001) surface, and its interfaces with GaAs and GaP semiconductors by using first-principles calculations based on density functional theory. The bulk FeMnSb reveals its half-metallic ferrimagnetism with 100% spin-polarization. Extending this study to the (001) surface, we uncover distinct electronic and magnetic behaviors for Fe- and MnSb-terminated surfaces, the MnSb-terminated surface preserving the half-metallicity observed in the bulk material. Our evaluation of the interfaces exhibits positive work of separation, indicating that these interfaces are energetically favorable. The density of states analysis reveals that all interfaces exhibit a metallic nature. High spin-polarization values, particularly 97.316% for the Fe-Ga interface, suggest a substantial degree of spin-polarized current. Notably, the absorption coefficient peaks shift from the ultraviolet (UV) region in the bulk alloy to the visible region at the (001) surfaces. However, at the FeMnSb/GaAs and FeMnSb/GaP interfaces, the highest absorption peaks revert to the UV region, highlighting strong interfacial coupling effects. These results suggest the tunability of FeMnSb optical properties via surface termination and interface engineering, making it a promising candidate for spintronic and optoelectronic applications.

Theoretical design of molecular diode based on thiol- and amino- terminated molecules

Utilizing density functional theory (DFT) and non-equilibrium Green’s function, we systematically studied the electrical transport and rectification properties of thiol- and amino-terminated molecules embedded in graphene nanoribbons. We firstly found the thiol-terminated molecules show better electron transport properties compared to the amino-terminated, which can be attributed to the strong electronwithdrawing ability and favorable coupling effects. Secondly, the symmetrical molecules show almost symmetrical current-voltage (I-V) curves and exhibit negligible rectification effects. On the other hand, the asymmetrical molecules exhibit asymmetrical I-V curves and better rectification performance. The rectification effect is closely related to molecular asymmetry degrees. For example, the rectification ratio of asymmetric N6 ((E)-Nl-(3-aminopropyl)-but-2-ene-1,4-diamine) molecule is much smaller than the N4 (5-phenylthiazole-2,4-diamine) and N5 (2,6-diaminohexane-1,1,5-triol) molecules. Furthermore, we found the rectification ratio of the asymmetrical amino-terminated molecules can reach 400, while the biggest rectification ratio of the thiol-terminated molecule can only reach 45. These findings offer crucial insights for future graphene molecular electronic device design.

Investigation of Coupling Effect for Adjacent Orthopedic Implants on MRI Radio-Frequency Heating

This paper investigates the mechanism of radio-frequency (RF) heating that occurs when two adjacent orthopedic implants are present together under magnetic resonance imaging (MRI) at 1.5 Tesla and 3.0 Tesla. When a patient has multiple implants close to each other, interactions between the implants may increase RF heating. Typical generic interlocking plate and antibiotic nail implants are adopted as examples. To analyze the effect of adjacent implants, the amplitude and direction of incident and scattering vector electric fields at the hot spot position are calculated and extracted using numerical simulation based on Huygens principle. It is shown that a strong coupling effect occurs due to the existence of both the incident field and a strong scattering field. Huygens principle can be used to obtain the first and second order scattering fields generated between implants. If the first- and second-order electric field terms are summed within a certain region, the RF-induced heating of this dual-implant system increases.

Construction of aptamers-modified plasmonic GO/urchin-like Au nanoparticles with enhanced photothermal performance and their efficient capture and elimination of Staphylococcus aureus

Here, aptamers-modified graphene oxide/urchin-like Au nanoparticles (Apt-GUANPs) were developed for efficient capture and photothermal therapy (PTT) of Staphylococcus aureus (S. aureus). Specifically, anisotropic UANPs were first prepared, and the excellent photothermal property was related to the localized surface plasmon resonance (LSPR) in the near infrared (NIR) region caused by sharp branching. Then GO, which was used to enhance the photothermal effect, was added and assembled into GUANPs by electrostatic action. Infrared images showed that GUANPs exhibited a stronger photothermal effect than UANPs. Under the irradiation of 808 nm laser, the photothermal conversion efficiency (η) of GUANPs was as high as 40.5 %, which was attributed to the enhanced optical response of GUANPs at 808 nm and the strong plasmonic coupling effect between tightly packed UANPs loaded on GO surfaces. Aptamers were modified on the surfaces of GUANPs for specific capture of S. aureus, with the capture efficiency of up to 72 %. Utilizing the specific capture ability of aptamers and the excellent photothermal property of GUANPs, Apt-GUANPs exhibited the strong photothermal killing ability against S. aureus. Therefore, Apt-GUANPs will be a promising and efficient photothermal agent, and will have a great application prospect in the treatment of bacterial infections in the future.

Strong Electron Coupling Effect of Prussian Blue Analogs Derived Ultrathin Nitrogen‐Doped Carbon Wrapped Fe‐CoP for Enhanced Wide Spectrum Photocatalytic H2 Evolution

AbstractWith the advantages of large specific surface area and high porosity of general metal‐organic frame materials, russian blue analogs have broad application prospects in catalysis. In this work, a series of ultra‐thin N‐doped carbon coated Fe‐CoP (Fe‐CoP@NC) are prepared by phosphating Fe‐Co‐Co Prussian blue analogs (Fe‐Co‐Co PBA) in different degrees for the broad‐spectrum photocatalytic hydrogen evolution. The results show that Fe‐CoP@NC‐3 has the highest photocatalytic hydrogen production rate of 16.6 mmol h−1 g−1, which is 83 times greater than that of Fe‐Co‐Co PBA. The excellent stability of Fe‐CoP@NC‐3 is proved by cyclic experiments. The outstanding photocatalytic H2 production activity of Fe‐CoP@NC‐3 can be ascribed to the strong electron coupling effect between Fe‐CoP and N‐doped carbon layer. The photogenerated electrons of Fe‐CoP are transferred to the N‐doped carbon layer, which is electron transport mediator accelerating the electron transfer and synergetic improving the hydrogen evolution efficiency. This work provides an effective strategy for designing an ultra‐thin N‐doped carbon layer coated phosphide photocatalyst with strong electron coupling effect.

Coupling effect of concrete cracks and stray current on chloride-induced corrosion of rebar

Either concrete cracking or stray current promotes the corrosion of rebars; however, the coupling effects of concrete cracking and stray current on the rebar corrosion are still unknown. In this work, the effect of concrete cracking patterns coupled with stray current on rebar corrosion is presented by both experimental and finite element simulation. Specifically, there is a strong coupling effect when crack width is less than 100 μm, which manifests that ion concentration and electric field intensity increase pronouncedly with decreasing crack width. Simulation shows that the coupling effect leads to an asymmetric distribution of ions and electric fields at the crack tip, which in turn causes the asymmetric corrosion of rebars. Under the coupling effect, the highest corrosion rate reaches 3 μA/cm2 and is more than three times higher than that in a natural environment. Our findings contribute to understanding and evaluating accurately rebar corrosion in practical application.

Experimental and simulation study of energy loss mechanism of low pressure ratio radial turbine

Low-pressure ratio conditions are commonly encountered in radial turbines. When operating at low pressure ratio condition, a significant portion of the turbine energy loss occurs as residual velocity loss in the form of swirling flow at the outlet pipe. Typically, this energy can be recovered by the next stage turbine or reduced by the diffuser. However, there is a lack of experimental and simulation studies on the swirling flow at the outlet of turbines. The mechanism governing the changing pattern of swirling flow remains unclear, limiting the effective utilization and reduction of residual velocity loss. This study conducts theoretical and experimental research on turbine outlet swirling flow. Firstly, this paper introduces a novel two-dimensional hot-wire anemometry stepping mechanism for measuring swirling flow at a turbine outlet cross-section. Experimental results demonstrate that the proposed measurement method effectively captures the morphological changes of turbine outlet swirling flow. The results indicate a strong coupling relationship between axial and circumferential velocity. Subsequently, to elucidate the reasons for the coupling of velocity in two directions and the development of swirling flow in the outlet pipeline, simulations of turbine performance under different velocity ratio conditions were conducted. Results show that under a wide range of velocity ratios, not only does the direction of the turbine outlet swirling flow change, but it also leads to the swirl number exceeding the critical swirl ratio under high velocity ratio conditions, resulting in the formation of a central recirculation zone (CRZ) at the pipe outlet. The main cause of the strong coupling effect between velocities in two directions is attributed to the increased swirl intensity leading to enhanced adverse pressure gradients at the core of the vortex. Lastly, a model describing the variation of VGT turbine outlet swirling flow is established, indicating a linear relationship between the swirl number and the velocity ratio, with a steeper change as the pressure ratio decreases.

Preparation of hollow CoFe Prussian blue analogues and their derived CoP-FeP nanoboxes as efficient electrocatalysts as oxygen evolution reactions

Reasonably designing and constructing transition metal based compounds with controllable composition and structure is a promising option for obtaining economically efficient oxygen evolution reaction (OER) electrocatalysts. This paper presents a one-pot self-templated epitaxial growth, phase transition and self-dissolution strategy for constructing hollow nanoboxes/solid nanocubes of CoFe bimetallic Prussian blue analogues (PBAs). The CoFe mixed phosphide with a porous hollow nanoboxes structure obtained after subsequent phosphating heat treatment exhibite enhanced OER electrocatalytic activity in alkaline media, exhibiting a low overpotential of 230 mV and a Tafel slope of 35.5 dec−1 at 10 mA cm−2, as well as excellent stability for 48 h. The excellent OER activity of CoP-FeP nanoboxes (CoP-FeP NBs) can be attributed to the combination effect between their composition and structure. Structurally, the exquisite porous hollow nanoboxes structure greatly expands the surface area, reduces ion diffusion pathways, and reduces charge transfer resistance. Compositionally, the inner transition metal phosphide exhibits good conductivity and undergoes surface reconstruction during OER, forming high valence Co(Fe)OOH active substances in situ. The strong interface coupling effect of CoOOH/FeOOH optimizes the electronic structure. This work presents a facile and efficient strategy for the construction of PBAs hollow structural materials and the exploitation of low-cost and efficient electrocatalysts.

Fe3O4/Au@SiO2 nanocomposites with recyclable and wide spectral photo-thermal conversion for a direct absorption solar collector

The Fe3O4-based photothermal materials have been widely applied for the recycling of heavy metal nanoparticles to avoid secondary pollution in the utilization of solar energy owing to excellent magnetic properties. However, the narrow absorption band of Fe3O4 or metal nanoparticles limits their capacity for solar energy harvesting. In this paper, a recyclable and wide spectral photo-thermal conversion system (Fe3O4/Au@SiO2) based on Fe3O4 nanospheres and SiO2-modified Au nanorods (NRs) is prepared. Owing to the strong coupling effect between Fe3O4 and different Au NRs, the wide and strong absorption band from 400 nm to 1100 nm is obtained. Under the influence of magnetic field, the temperature change of nanofluids (NFs) at different positions can be controlled. When the concentration is 0.0467 vol%, the solar energy absorption fraction reaches 96.50 %. Besides, the photothermal performance of Fe3O4/Au@SiO2 NFs at different flow rates is investigated and the results show that temperature rise decreases as increasing flow rate. Finally, a water evaporator device based Fe3O4/Au@SiO2 NFs is developed. The maximum water evaporation rate of 2.6 kg m−2 h−1 can be reached and the movement of evaporator on water can be operated using magnetic field, showing great photothermal conversion performance and recovery potential in practical applications.

A one-stone-three-birds strategy to construct Mo-FeS2/Ni3S2@C electrocatalyst with strong interfacial coupling effect to achieve efficient oxygen evolution reaction

The development of high-performance oxygen evolution reaction (OER) electrocatalysts is quite pivotal to facilitate hydrogen production. In this work, we integrate the synergistic effects of heterogeneous interface engineering, multiscale engineering and doping engineering to greatly improve the catalytic activity of the electrocatalyst. Specifically, with a Anderson-type polymetallic oxonate (NH4)3[NiMo6O24H6]·7H2O as a precursor, the Mo-FeS2/Ni3S2@C nanowire arrays that uniformly grown on nickel foam (NF) surfaces were prepared by a simple hydrothermal process followed by calcination. The as-prepared Mo-FeS2/Ni3S2@C exhibits excellent alkaline OER performance with a low overpotential of 196 mV to achieve a current density of 10 mA cm−2 and maintain high stability for over 100 h at 100 mA cm−2. Theoretical calculations and experimental results indicate that the high activity of Mo-FeS2/Ni3S2@C is mainly attributed to the charge interaction at the multiple interfaces of FeS2, Ni3S2 and porous carbon layers. The Mo facilitates inducing the formation of high-valent Ni, Fe, thus forming of the Ni(Fe)OOH phase that contributes to the intrinsic OER active site of the Mo-FeS2/Ni3S2@C electrode. In addition, the surface of Mo-FeS2/Ni3S2@C nanowire is composed of ordered nanosheets, exhibiting a unique hierarchical multi-scale structure, which is conducive to exposing more active sites. This hierarchical structure gives it superhydrophilic and superoxyphobic properties, ensuring the stability during continuous electrolysis. This study showcases the importance of multi-engineering synergies and foresees the avenue of designing novel OER electrocatalysts.

Interface enhanced magnetoelectric coupling effect of multiferroic liquids based on CoFe2O4@BaTiO3 core shell particles

A new type CoFe2O4@BaTiO3 (CFO@BTO) multiferroic liquid with different CoFe2O4 (CFO) particle sizes was constructed, and its magnetic properties, electrical properties, and magnetoelectric coupling effects were systematically studied. XRD results show that the CFO phase has a spinel structure, whereas the BaTiO3 (BTO) phase has a perovskite structure, with no obvious heterophase formation. It can be seen from the SEM diagram that the CFO powder has a cuboid shape, and the CFO particle size (1.56 × 0.58 × 0.48 µm, 3.16 × 1.04 × 0.66 µm, 6.47 × 1.53 × 1.40 µm, and 11.19 × 2.64 × 2.28 µm) gradually increased with increasing calcination temperature(T = 450 ℃, 550 ℃, 650 ℃, 750 ℃). TEM results show that the composite particles have obvious core-shell structure. From the hysteresis loop, it can be seen that the saturation magnetization (Ms) of the CFO@BTO powder gradually increases with increasing CFO size. The sedimentation stability of the multiferroic liquid gradually decreases, the dielectric constant and residual polarization (Pr) decrease first and then increase, and the magnetoelectric coefficient and magnetoelectric coupling coefficient increase first and then decrease. When the particle size of the CFO is 6.47 × 1.53 × 1.40 µm, the maximum magnetoelectric coupling coefficient is 210.76 V/(cm·Oe) under an applied magnetic field of 50 Oe, which realizes a strong magnetoelectric coupling effect at room temperature.

Axial vibration characteristics analysis of transformer windings based on magnetic‐structural coupling correction model

AbstractDue to the strong coupling effect between the internal magnetic field and the structural field of the transformer, the magnetic‐structural coupling should be considered in axial vibration process of the winding short‐circuit impact. A 110 kV transformer is taken as the research object. Firstly, the vibration modal characteristics of the transformer are calculated using the classical axial vibration model, and the spatial distribution of the leakage magnetic flux density of the iron core window is obtained based on the image method, which is used as the basis for calculating the excitation electromagnetic force. With the consideration of the non‐linear mechanical characteristic of the pad, the dynamic stiffness equation is analysed and established and the magnetic‐structural coupling correction model is constructed. Finally, the winding vibration amplitudes obtained respectively by the classical model, the magnetic‐structural coupling model, and the magnetic‐structural coupling correction model considering the dynamic stiffness are compared. The results show that, compared with the classical model, the vibration amplitude increment with the magnetic‐structural coupling correction model is less. The dynamic stiffness will hinder the vibration intensification. The magnetic‐structural coupling correction model can provide a more accurate calculation scheme for the winding vibration characteristic analysis.

Strong electron coupling effect of non-precious metal Schottky junctions enhanced square meter level photocatalytic hydrogen evolution

Photocatalytic hydrogen production technology utilizes solar energy to decompose water into hydrogen, helping to alleviate the pressure of energy depletion. Engineering of non-precious metal nanomaterials as cocatalysts can play a significant role in low-cost, sustainable, and large-scale photocatalytic hydrogen production. Herein, MnCdS-Vs/NiCo2S4 (MCSN) Schottky junction nanomaterials with strong electron coupling effect were prepared by a two-step hydrothermal method and successfully applied to a square meter hydrogen evolution device. The optimized MCSN material demonstrated high hydrogen evolution activity of 34.28 mmol g−1 h−1, which is 9.34 and 685.60 times higher than that of pure MnCdS-Vs and NiCo2S4, respectively. More importantly, in a square meter (1 m2) flat-plate reactor, MCSN produced H2 evolution approximately 201 mmol in 5 h, showcasing its potential for large-scale applications. In-situ XPS and DFT calculations demonstrated that MnCdS-Vs interacts with NiCo2S4 to produce a strong electron coupling effect and form a Schottky junction. It promotes the facilitated the directional migration of photogenerated electrons from MnCdS-Vs to NiCo2S4, but also effectively suppressed electron backflow through the Schottky barrier. Furthermore, the abundance of sulfur vacancies enhanced visible light absorption capability, further improving photocatalytic hydrogen evolution performance. This work delves into the role of defect engineering and Schottky junction design in enhancing photocatalytic performance, providing new insights into transitioning photocatalytic hydrogen production technologies from small-scale laboratory experiments to large-scale practical applications.

Strong electron coupling between amorphous WP and MoSe2/ZnCdS S-scheme heterojunction for enhanced wide spectrum photocatalytic hydrogen production

The photogenerated carrier separation efficiency is a key factor for limiting the photocatalytic activity. In this work, an amorphous WP modified S-scheme MoSe2/ZnCdS (WP/MoSe2/ZCS) heterojunction was synthesized for wide spectrum photocatalytic hydrogen production. After initially forming an S-scheme heterojunction by compositing ZnCdS with nano flower-shaped MoSe2, the light absorption ability of the bimetallic sulfide was significantly enhanced, along with an improved photogenerated carrier separation efficiency. Additionally, the introduction of WP as a co-catalyst not only provides more active sites for photocatalytic reactions, but also enhances the photogenerated electrons transfer through the synergistic effect of strong electronic coupling and S-scheme MoSe2/ZCS heterojunction.The significant enhancement of photocatalytic hydrogen evolution activity of 7％WP/MoSe2/ZCS reached 47.7 mmol g−1 h−1, which is 4.72 times higher than that of ZnCdS (10.1 mmol g−1 h−1). The strong electron coupling effects and S-scheme electron ransfer mechanism was proved by in-situ XPS and Density functional theory (DFT) calculations. This work provides a new strategy for the construction of high-efficiency photocatalyst with strong electronic coupling.