High-Entropy Alloy Electrocatalysts Bidirectionally Promote Lithium Polysulfide Conversions for Long-Cycle-Life Lithium-Sulfur Batteries.

High-entropy alloys (HEAs) have attracted considerable attention, owing to their exceptional characteristics and high configurational entropy. Recent findings demonstrated that incorporating HEAs into sulfur cathodes can alleviate the shuttling effect of lithium polysulfides (LiPSs) and accelerate their redox reactions. Herein, we synthesized nano Pt0.25Cu0.25Fe0.15Co0.15Ni0.2 HEAs on hollow carbons (HCs; denoted as HEA/HC) by a facile pyrolysis strategy. The HEA/HC nanostructures were further integrated into hypha carbon nanobelts (HCNBs). The solid-solution phase formed by the uniform mixture of the five metal elements, i.e., Pt0.25Cu0.25Fe0.15Co0.15Ni0.2 HEAs, gave rise to a strong interaction between neighboring atoms in different metals, resulting in their adsorption energy transformation across a wide, multipeak, and nearly continuous spectrum. Meanwhile, the HEAs exhibited numerous active sites on their surface, which is beneficial to catalyzing the cascade conversion of LiPSs. Combining density functional theory (DFT) calculations with detailed experimental investigations, the prepared HEAs bidirectionally catalyze the cascade reactions of LiPSs and boost their conversion reaction rates. S/HEA@HC/HCNB cathodes achieved a low 0.034% decay rate for 2000 cycles at 1.0 C. Notably, the S/HEA@HC/HCNB cathode delivered a high initial areal capacity of 10.2 mAh cm-2 with a sulfur loading of 9 mg cm-2 at 0.1 C. The assembled pouch cell exhibited a capacity of 1077.9 mAh g-1 at the first discharge at 0.1 C. The capacity declined to 71.3% after 43 cycles at 0.1 C. In this work, we propose to utilize HEAs as catalysts not only to improve the cycling stability of lithium-sulfur batteries, but also to promote HEAs in energy storage applications.

Oxygen-vacancy-reinforced perovskites promoting polysulfide conversion for lithium-sulfur batteries.

Lithium-sulfur batteries (LSBs) are considered to be one of the most promising energy storage systems because of the ultrahigh energy density. However, their shuttle effect and slow redox kinetics seriously hinder the development of LSBs. To solve these issues, the perovskite La1-xSrxMnO3-δ (x = 0-0.5) with different oxygen vacancy concentrations were prepared by a facile liquid-phase synthesis and followed by the thermal annealing. The La1-xSrxMnO3-δ can not only anchor lithium polysulfides (LiPSs), but also catalyze the conversion of LiPSs. The detailed kinetic analysis and density functional theory calculations reveal that the optimal level of oxygen vacancies can effectively increase the binding energy between perovskites and LiPSs, and effectively promote the LiPS conversion kinetics. The S/La0.6Sr0.4MnO3-δ cathode with a moderate oxygen vacancy concentration exhibits high rate performance and ultrahigh capacity retention of 93.2% after 150 cycles at 0.1 C, which provides a potential for practical applications of LSBs. This work reveals the application of perovskite materials in the development of advanced LSBs.

Exquisitely constructing hierarchical carbon nanoarchitectures decorated with sulfides for high-performance Li-S batteries.

The sluggish reaction kinetics and notorious shuttle effect of polysulfides significantly hinder the practical application of lithium-sulfur batteries (LSBs). Therefore, polysulfides are anchored and their conversion reactions are catalyzed to enhance the performance of LSBs. Herein, an exquisite hierarchical carbon nanoarchitecture decorated with sulfides is designed and introduced into LSBs. Systematic experiments show that the nanoarchitecture not only enables rapid electron/ion migration but also functions as an active catalyst to increase polysulfide conversion, thus effectively reducing the shuttle effect. As a result, LSBs with the nanoarchitecture modified separator exhibited outstanding rate capacity (724.9 mA h g-1 at 5C), low self-discharge capacity loss (4.1% capacity loss after 72 h), and exceptional reversible capacity (1518.3 mA h g-1 at 0.1C and 25.6% capacity loss after 100 cycles). Through the design of a multifunctional separator, this study offers an effective way to minimize the shuttle effect and speed up redox conversion. The strategy of constructing nanoarchitectures provides an innovative route for hierarchical heterocatalyst design for LSBs.

Nitrogen and Sulfur Co-Doped Carbon-Coated Ni3 S2 /MoO2 Nanowires as Bifunctional Catalysts for Alkaline Seawater Electrolysis.

Bifunctional catalysts have inherent advantages in simplifying electrolysis devices and reducing electrolysis costs. Developing efficient and stable bifunctional catalysts is of great significance for industrial hydrogen production. Herein, a bifunctional catalyst, composed of nitrogen and sulfur co-doped carbon-coated trinickel disulfide (Ni3 S2 )/molybdenum dioxide (MoO2 ) nanowires (NiMoS@NSC NWs), is developed for seawater electrolysis. The designed NiMoS@NSC exhibited high activity in alkaline electrolyte with only 52 and 191 mV overpotential to attain 10 mA cm-2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. Significantly, the electrolyzer (NiMoS@NSC||NiMoS@NSC) based on this bifunctional catalyst drove 100 mA cm-2 at only 1.71 V along with a robust stability over 100 h in alkaline seawater, which is superior to a platinum/nickel-iron layered double hydroxide couple (Pt||NiFe LDH). Theoretical calculations indicated that interfacial interactions between Ni3 S2 and MoO2 rearranged the charge at interfaces and endowed Mo sites at the interfaces with Pt-like HER activity, while Ni sites on Ni3 S2 surfaces at non-interfaces are the active centers for OER. Meanwhile, theoretical calculations and experimental results also demonstrated that interfacial interactions improved the electrical conductivity, boosting reaction kinetics for both HER and OER. This study presented a novel insight into the design of high-performance bifunctional electrocatalysts for seawater splitting.

In-situ reconstruction of rock-like 3D hierarchical MIL-53(Fe) self-supporting electrode with oxygen vacancy induced ultra-long stable and efficient water oxidation.

The exploitation of efficient, stable and cheap electrocatalyst for oxygen evolution reaction (OER) is very significant to the development of energy technology. In this study, Fe-based metal-organic frameworks (MIL-53(Fe)) self-supporting electrode with a 3D hierarchical open structure was developed through a semi-sacrificial strategy. The self-supporting electrode exhibits an excellent OER performance with an overpotential of 328 mV at 100 mA cm-2 in 1 M KOH, which is superior than that of IrO2 catalyst. Importantly, the optimized self-supporting electrode could operate at 100 mA cm-2 for 520 h without visible decrease in activity. It was also found that the structure of MIL-53(Fe) was in-situ self-reconstructed into oxyhydroxides during OER process. However, the 3D hierarchical open structure assembled with nano-microstructures kept well, which ensured the long-term stability of our self-supporting electrode for OER. Furthermore, density functional theory (DFT) calculations reveal that the FeOOH with rich oxygen vacancy transformed from MIL-53(Fe) plays a key role for the OER catalytic activity. And, the uninterrupted formation of oxygen vacancy during OER process ensures the continuous OER catalytic activity, which is the original source for the ultra-long stability of the self-supporting electrode toward OER. This work explores the way for the construction of efficient self-supporting oxygen electrodes based on MOFs.

Platinum Electrocatalyst Promoting Redox Kinetics of Li2S and Regulating Li2S Nucleation for Lithium-Sulfur Batteries.

The development of lithium-sulfur batteries (LSBs) is impeded by the shuttle effect of polysulfides (LiPSs) and the sluggish nucleation of Li2S. To address these challenges, incorporating electrocatalysts into sulfur host materials represents an effective strategy for promoting polysulfide conversion, in tandem with the rational design of multifunctional sulfur host materials. In this study, Pt nanoparticles are integrated into biomass-derived carbon materials by solution deposition method. Pt, as an electrocatalyst, not only enhances the electrical conductivity of sulfur cathodes and effectively immobilizes LiPSs but also catalyzes the redox reactions of sulfur species bidirectionally. Additionally, Pt helps regulate the 3D deposition and growth of Li2S while reducing the reaction energy barrier. Consequently, this accelerates the conversion of LiPSs in LSBs. Furthermore, the catalytic ability of Pt for the redox reactions of sulfur species, along with its influence on the 3D deposition and growth of Li2S, is elucidated using electrochemical kinetic analyses and classical models of electrochemical deposition. The cathodes exhibit a high initial specific capacity of 1019.1 mAh g-1 at 1 C and a low decay rate of 0.045% over 1500 cycles. This study presents an effective strategy to regulate Li2S nucleation and enhance the kinetics of polysulfide conversion in LSBs.

CoS2@C catalyzes polysulfide conversion to promote the rate and cycling performances of lithium-sulfur batteries.

Lithium-sulfur (Li-S) batteries have been considered one of the most promising candidates for next-generation energy storage devices due to their high theoretical energy density and low cost. Nonetheless, the practical application of Li-S batteries is still inhibited by their lithium polysulfide (LiPS) shuttling and sluggish redox kinetics, which cause rapid capacity decay and inferior rate performance. Hence, anchoring LiPSs and catalyzing their conversion reactions are imperative to enhance the performance of Li-S batteries. In this work, one-dimensional (1D) porous carbon-encapsulated CoS2 (CoS2@C) fiber structures were prepared through a simple two-step hydrothermal reaction and they exhibited a robust LiPS trapping ability and rapid catalytic conversion of LiPSs. The formed three-dimensional (3D) architecture (CoS2@C/MWCNT) facilitates the physical adsorption of LiPSs and rapid ion transport. The electrode exhibited a high initial capacity of 1329.5 mA h g-1 at a current density of 0.1 C and a reversible capacity of 1060.6 mA h g-1 after 100 cycles, with an 80% capacity retention rate. Meanwhile, the decay rate of the electrode is 0.048% per cycle at 1 C and after 500 cycles. With a sulfur loading of 3 mg cm-2, the capacity retention rate is approximately 83.7% after 80 cycles.

Dual-Functional Z-Scheme TiO2 @MoS2 @NC Multi-Heterostructures for Photo-Driving Ultrafast Sodium Ion Storage.

Exploiting dual-functional photoelectrodes to harvest and store solar energy is a challenging but efficient way for achieving renewable energy utilization. Herein, multi-heterostructures consisting of N-doped carbon coated MoS2 nanosheets supported by tubular TiO2 with photoelectric conversion and electronic transfer interfaces are designed. When a photo sodium ion battery (photo-SIB) is assembled based on the heterostructures, its capacity increases to 399.3 mAh g-1 with a high photo-conversion efficiency of 0.71 % switching from dark to visible light at 2.0 A g-1 . Remarkably, the photo-SIB can be recharged by light only, with a striking capacity of 231.4 mAh g-1 . Experimental and theoretical results suggest that the proposed multi-heterostructures can enhance charge transfer kinetics, maintain structural stability, and facilitate the separation of photo-excited carriers. This work presents a new strategy to design dual-functional photoelectrodes for efficient use of solar energy.

In situ artificial solid electrolyte interface engineering on an anode for prolonging the cycle life of lithium-metal batteries.

Lithium, with its high theoretical capacity and low potential, has been widely investigated as the anode in energy storage/conversion devices. However, their commercial applications always suffer from undesired dendrite growth, which forms in the charging process and may puncture the separator, leading to short cycle lives and even security problems. Herein, by an in situ displacement reaction using SnF2 at room temperature, we constructed an artificial solid electrolyte interface (ASEI) of LiF/Li-Sn outside the Li anode. This hybrid strategy can induce a synergy between the high Li+ conductivity of the Li-Sn alloy and good electrical insulation of LiF. Moreover, extreme synergy can be achieved by moderating the thickness of the LiF/Li-Sn ASEI, guiding dendrite-free lithium plating and stripping. As a result, a Li//LiFePO4 battery that is assembled from the LiF/Li-Sn ASEI-engineered Li anode can obtain 1000 cycled lives with 86.3% capacity retention under a charge/discharge rate of 5 C. This work provides an alternative way to construct dendrite-free lithium metal anodes, which significantly benefit the cycle lives of LMBs.

A High-Rate and Long-Life Aqueous Rechargeable Mg-Ion Battery Based on an Organic Anode Integrating Diimide and Triazine.

Aqueous Mg-ion batteries (MIBs) lack reliable anode materials. This study concerns the design and synthesis of a new anode material - a π-conjugate of 3D-poly(3,4,9,10-perylenetracarboxylic diimide-1,3,5-triazine-2,4,6-triamine) [3D-P(PDI-T)] - for aqueous MIBs. The increased aromatic structure inhibits solubility in aqueous electrolytes, enhancing its structural stability. The 3D-P(PDI-T) anode exhibits several notable characteristics, including an extremely high rate capacity of 358 mAh g-1 at 0.05 A g-1 , A 3D-P(PDI-T)‖Mg2 MnO4 full cell exhibits a reversible capacity of 148 mAh g-1 and a long cycle life of 5000 cycles at 0.5 A g-1 . The charge storage mechanism reveals a synergistic interaction of Mg2+ and H+ cations with C-N/C=O groups. The assembled 3D-P(PDI-T)‖Mg2 MnO4 full cell exhibits a capacity retention of around 95 % after 5000 cycles at 0.5 A g-1 . This 3D-P(PDI-T) anode sustained its framework structure during the charge-discharge cycling of Mg-ion batteries. The reported results provide a strong basis for a cutting-edge molecular engineering technique to afford improved organic materials that facilitate efficient charge-storage behavior of aqueous Mg-ion batteries.

Tuning Li Nucleation by a Hybrid Lithiophilic Protective Layer for High-Performance Lithium Metal Batteries.

Lithium (Li) metal has been recognized as the most promising anode material for next-generation rechargeable batteries. However, the practical application of Li anodes is hampered by the growth of Li dendrites. To address this issue, a robust and uniform Sb-based hybrid lithiophilic protective layer is designed and built by a facile in situ surface reaction approach. As evidenced theoretically and experimentally, the as-prepared hybrid protective layer provides outstanding wettability and fast charge-transfer kinetics. Moreover, the lithiophilic Sb embedded in the protective layer provides a rich site for Li nucleation, which effectively reduces the overpotential and induces uniform Li deposition. Consequently, the symmetric cell exhibits a long lifespan of over 1600 h at 1 mA cm-2 and 1 mAh cm-2 with a low voltage polarization. Furthermore, excellent cycling stability is also obtained in Li-S full cells (60% capacity retention in 800 cycles at 1 C) and Li||LFP full cells (74% capacity retention in 500 cycles at 5 C). This work proposed a facile but efficient strategy to stabilize the Li metal anode.

NiO/Ni Heterojunction on N-Doped Hollow Carbon Sphere with Balanced Dielectric Loss for Efficient Microwave Absorption.

Hollow carbon spheres are potential candidates for lightweight microwave absorbers. However, the skin effect of pure carbon-based materials frequently induces a terrible impedance mismatching issue. Herein, small-sized NiO/Ni particles with heterojunctions on the N-doped hollow carbon spheres (NHCS@NiO/Ni) are constructed using SiO2 as a sacrificing template. The fabricated NHCS@NiO/Ni displayed excellent microwave absorbability with a minimum reflection loss of -44.04 dB with the matching thickness of 2 mm and a wider efficient absorption bandwidth of 4.38 GHz with the thickness of 1.7 mm, superior to most previously reported hollow absorbers. Experimental results demonstrated that the excellent microwave absorption property of the NHCS@NiO/Ni are attributed to balanced dielectric loss and optimized impedance matching characteristic due to the presence of NiO/Ni heterojunctions. Theoretical calculations suggested that the redistribution of charge at the interfaces and formation of dipoles induced by N dopants and defects are responsible for the enhanced conduction and polarization losses of NHCS@NiO/Ni. The simulations for the surface current and power loss densities reveal that the NHCS@NiO/Ni has- applicable attenuation ability toward microwave under the practical application scenario. This work paves an efficient way for the reasonable design of small-sized particles with well-defined heterojunctions on hollow nanostructures for high-efficiency microwave absorption.

Role of introduced Se element and induced anion vacancies in Mo(SSe)2-x/G van der Waals heterostructure for enhanced hydrogen evolution reaction.

The Gibbs free energy of hydrogen adsorption at the edge of molybdenum disulfide (MoS2) is close to that of Pt, meaning that MoS2 is the best candidate to replace Pt-based materials. However, easy agglomeration between layers to mask active sites, lack of catalytic activity in the basal planes, and poor electronic conductivity make MoS2 exhibit dissatisfactory hydrogen evolution reaction (HER) catalytic performance. Here, we successfully construct a van der Waals heterostructure stacked alternately with Mo(SSe)2-x and graphene (Mo(SSe)2-x/G) to enhance its catalytic ability. The introduction of Se into MoS2 and the thermal treatment induce the sample to generate more anion vacancies. Theoretical and experimental results demonstrate the constructed van der Waals heterostructure, the introduced Se element, and the increased anion vacancies are in favor of promoting the number of active sites and improving the electronic conductivity of the catalyst. Therefore, Mo(SSe)2-x/G exhibits superior HER catalytic performance (the overpotentials of 137 mV and 136 mV at a current of 10 mA cm-2) and long-term stabilities (>90 h and 140 h at a current density of 20 mA cm-2) in both acidic and alkaline media.

Mott-Schottky electrocatalyst selectively mediates the sulfur species conversion in lithium-sulfur batteries.

The lithium sulfur (Li-S) battery is an active research area in the field of energy storage systems, but the shuttle effect is a serious obstacle hindering its application. Herein, a CoSe2/CoO Mott-Schottky catalyst is blended with carbon nanotubes (CNTs) and subsequently coated onto a commercial separator as a modifier, whereby the synergy between the high electrocatalytic activity of the CoSe2/CoO heterostructure and high conductivity of the CNTs selectively mediate the conversion of sulfur species. As a result, a cell with a CoSe2/CoO-CNTs modified separator displays a high initial discharge capacity of 1573 and 910 mAh/g at 0.1 and 2C, respectively. Furthermore, a low decay rate of 0.070% per cycle can be obtained over 500 cycles at 2C. The results of this study suggest that the as-prepared CoSe2/CoO-CNTs is an effective modifier that can improve the performance of Li-S batteries for use in next-generation energy storage systems. This study provides fundamental insights into the rational design of Mott-Schottky catalysts for practical high-performance Li-S batteries.

Boosted charge transfer in ReS2/Nb2O5 heterostructure by dual-electric field: Toward superior electrochemical reversibility for lithium-ion storage.

Heterostructures with the electric field effect can excite the charge transfer kinetics of materials due to the driving force of the electric field. Herein, we report a new ReS2/Nb2O5 heterostructure of rhenium disulfide coupled to niobium oxide with a mutually compatible band structure and enriched oxygen vacancies. The unique heterostructure can facilitate the redistribution of charges to induce built-in electric fields and microlocalized electric fields. As expected, the ReS2/Nb2O5 heterostructure shows a superior lithium-ion reversible capacity of 805 mAh g-1 after 2400 h at 0.10 A g-1, and 414 mAh g-1 at 2.00 A g-1. In addition, in situ X-ray diffraction and ex situ X-ray photoelectron spectroscopy analysis reveal the phase transition process of the ReS2/Nb2O5 heterostructure during the electrochemical reaction. This provides deeper insights into the construction of high-performance lithium-ion storage materials based on heterostructures with dual-electric field-driven charge transfer.

Modulating Electron Conducting Properties at Lithium Anode Interfaces for Durable Lithium-Sulfur Batteries.

The lithium (Li) ion and electron diffusion behaviors across the actual solid electrolyte interphase (SEI) play a critical role in regulating the Li nucleation and growth and improving the performance of lithium-sulfur (Li-S) batteries. To date, a number of researchers have pursued an SEI with high Li-ion conductivity while ignoring the Li dendrite growth caused by electron tunneling in the SEI. Herein, an artificial anti-electron tunneling layer with enriched lithium fluoride (LiF) and sodium fluoride (NaF) nanocrystals is constructed using a facile solution-soaking method. As evidenced theoretically and experimentally, the LiF/NaF artificial SEI exhibits an outstanding electron-blocking capability that can reduce electron tunneling, resulting in dendrite-free and dense Li deposition beneath the SEI, even with an ultrahigh areal capacity. In addition, the artificial anti-electron tunneling layer exhibits improved ionic conductivity and mechanical strength, compared to those of routine SEI. The symmetric cells with protected Li electrodes achieve a stable cycling of 1500 h. The LiF/NaF artificial SEI endows the Li-S full cells with long-term cyclability under conditions of high sulfur loading, lean electrolyte, and limited Li excess. This study provides a perspective on the design of the SEI for highly safe and practical Li-S batteries.

3D hierarchical Cu@Ag nanostructure as a current collector for dendrite-free lithium metal anode.

Lithium metal is considered to be the best candidate for rechargeable batteries due to its unique advantages. But the instability and the uncontrollable dendrites of the lithium metal anode greatly limit its commercialization. In recent years, in order to obtain stable Li metal anodes, various three-dimensional (3D) current collectors have been proposed. However, for traditional 3D current collectors, its advantages in structure still need to be improved. Therefore, the 3D hierarchical Cu@Ag nanostructure consisting of Ag-decorated Cu nanowires grown on Cu foam as a current collector (denoted as 3D HCu@Ag) is well designed and successfully prepared. Cu nanowires were in situ grown on Cu foam to form a 3D hierarchical current collector to further increase the specific surface area and reduce the local current density, thus suppressing the formation of dendrites. Ag nanoparticles were in situ grown on the surface of Cu nanowires by displacement reaction, which can reduce the overpotential of lithium deposition. Under the synergistic effect of optimal structure and Ag surface modification, 3D HCu@Ag exhibits extremely excellent performance. As a result, the Li-3D HCu@Ag symmetrical cell exhibits a lifetime of 1500 h with a very low voltage hysteresis. More importantly, in practical application, the Li-3D HCu@Ag||LFP full cell can cycle stably for 200 cycles at 1C and maintain an extremely high-capacity retention rate of 78.5%. The experiment results show that this design provides a new idea for the lithiophilic 3D current collector for stable lithium metal anode.

Mixed-dimensional V2CTx/Ti3C2Tx composite interlayer to boost electrochemical performance of Li-S batteries.

A mixed-dimensional V2CTx/Ti3C2Tx composite interlayer was successfully prepared to tackle severe polysulfide (LiPS) shuttling and sluggish sulfur redox kinetics for high-performance lithium-sulfur batteries. In the unique nanoarchitecture, two-dimensional Ti3C2Tx nanosheets served as a stable skeleton with superb electronic conductivity, good mechanical strength, and high polysulfide adsorption, whereas one-dimensional V2CTx nanorods played a crucial role in chemisorbing LiPSs and catalyzing the conversion of LiPSs due to their high polarity and electrocatalysis. With the synergistic effect of V2CTx and Ti3C2Tx composite nanostructures, the cells with the mixed-dimensional V2CTx/Ti3C2Tx composite interlayer showed an impressive long-term cycling stability and small capacity decay rate of 0.062% per cycle over 600 cycles at 1 C and exhibited an outstanding rate capability of 935.3 mAh·g-1 at 2 C.

Shielding polysulfides enabled by a biomimetic artificial protective layer in lithium-sulfur batteries.

Lithium-sulfur (Li-S) batteries are widely considered to be next-generation storage technologies due to their high energy density, low cost and non-toxicity. However, the soluble lithium polysulfides (LiPS) migrating to the anode side inevitably causes side reactions with the Li anode, resulting in severe corrosion of the Li anode, loss of active materials, and rapid battery failure. Therefore, it is necessary to develop effective strategies to avoid LiPS exposure to Li anodes. Herein, a stable UiO-66-ClO4/PDMS (PDUO-Cl) biomimetic protective layer is rationally constructed by the drip coating method. The PDUO-Cl protective layer can effectively suppress the side reaction of Li metal with LiPSs/electrolyte and homogenize the Li+ flux, thus avoiding corrosion of the Li metal anode. As a result, the symmetric cell with the PDUO-Cl protective layer delivers a stable cycle performance greater than 1400 h under a current density of 0.5 mA cm-2. The Li-S batteries with a PDUO-Cl protective layer still show relatively better rate performance and cycling stability (69% after 100 cycles at 0.1 C). This work provides new insights into the design of protective strategies for Li anodes in Li-S batteries.

Metal-organic framework interface engineering for highly efficient oxygen evolution reaction.

Metal-organic frameworks (MOFs) with intrinsically porous structures and well-dispersed metal sites are promising candidates for the oxygen evolution reaction (OER). However, the practical applications of MOFs for OER are significantly constrained due to their poor charge transfer property and insufficient inherent activity. Herein, we utilized caffeic acid as a bridging agent to covalently bond FeNi-MOF with NiMoO4 in order to tune the charge transfer properties for efficient OER. The optimized organic-inorganic heterocatalyst demonstrates superior OER performance with a low overpotential of 256 mV at a current density of 10 mA cm-2 and long-term stability, outperforming the benchmark IrO2 catalyst and single counterparts. Both experimental and theoretical results indicate that electrons can be transferred from FeNi-MOF to NiMoO4 via a caffeic acid bridging agent, which improves not only the electrical conductivity but also the adsorption capacity of OH- intermediates on MOFs. Therefore, the enhanced OER activity of the heterocatalyst is attributed to the synergistic effects of the multi-components. This study paves the way for the rational design of MOFs-based heterostructures towards efficient electrocatalytic oxygen evolution.