Heterostructure Electrocatalyst Research Articles

Novel Heterostructure-Based CoFe and Cobalt Oxysulfide Nanocubes for Effective Bifunctional Electrocatalytic Water and Urea Oxidation.

The development of effective oxygen evolution reaction (OER) and urea oxidation reaction (UOR) on heterostructure electrocatalysts with specific interfaces and characteristics provides a distinctive character. In this study, heterostructure nanocubes (NCs) comprising inner cobalt oxysulfide (CoOS) NCs and outer CoFe (CF) layered double hydroxide (LDH) are developed using a hydrothermal methodology. During the sulfidation process, the divalent sulfur ions (S2-) are released from the breakdown of the sulfur source and react with the Co-precursors on the surface leading to the transformation of CoOH nanorods into CoOS nanocubes. Further, X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) analyses reveal that the interactions at the interface of the CF@CoOS NCs significantly altered the electronic structure, thus enhancing the electrocatalytic performance. The optimal catalysts exhibited effective OER and UOR activities, the attained potentials are 1.51 and 1.36V. This remarkable performance is attributable to the induction of electron transfer from the CoFe LDH to CoOS, which reduces the energy barrier of the intermediates for the OER and UOR. Furthermore, an alkaline water and urea two-cell electrolyzer assembled using CF@CoOS-2 NCs and Pt/C as the anode and cathode requires a cell voltage of 1.63 and 1.56V along with a durability performance.

Heterostructure CoS2/MoS2 Nanosheets as a Dual-Active Electrocatalyst for the Oxygen Evolution Reaction.

Cost-effective and earth-abundant oxygen evolution reaction (OER) electrocatalysts are an incredible research hotspot in numerous energy storage and conversion technology fields. Herein, CoS2/MoS2 nanosheets supported by carbon cloth as a dual-active CC@CoS2/MoS2 heterostructure electrocatalyst is prepared through a simple solvothermal method. The catalyst demonstrates admirable OER performance in 1 M KOH solution with a low overpotential of 243 mV at a current density of 10 mA cm-2 and a minor Tafel slope of 109 mV dec-1, displaying honorable stability after 1000 cyclic voltammetry (CV) cycles and long-term robustness over 60 h. Theoretical calculations further ascertain that the rate-determining step of the electrocatalytic course of the CC@CoS2/MoS2 heterostructure is the conversion *O + OH- → *OOH + e- with a lower energy barrier of 1.49 eV due to the heterojunction established by CoS2 and MoS2, which can promote the OER performance of electrocatalysts. The actual identification of the catalytic mechanism in the heterostructure is conducive to the improvement of electrocatalysis applications in the OER.

In-situ electrochemical self-reconstruction of permeable Ni(OH)2/Pt hybrid for accelerating alkaline hydrogen evolution

Pt-based hybrid materials are demonstrated to be the most effective catalysts for alkaline hydrogen evolution reactions (HER) due to the synergy effect of heterogeneous interfaces. However, the heterogeneous interfaces are often constructed at the sacrifice of the electrochemical active surface area to cause relatively lower HER activity than expected. Herein, a permeable Ni(OH)2 layer and strained Pt atoms heterogeneous interface with enhanced electrocatalytic activity and minimal loss of active surface sites have been created by using an in-situ electrochemical self-reconstruction strategy. The permeable Ni(OH)2 layer promotes H2O dissociation without blocking proton contact with the active Pt sites. This unique design creates a favorable local acid-like environment that results in an ultra-high mass activity of 17.8 A mgPt−1 at an overpotential of 70 mV, which is 20.5 times superior to that of the commercial Pt/C catalyst and higher than those of the previously reported Pt-based catalysts. Meanwhile, the HER overpotential displays as low as 15 mV at 10 mA cm−2, showing superior HER efficiency and representing one of the optimal Pt-based HER catalysts in alkaline solution. In-situ Raman spectroscopy and DFT calculations prove that the interfacial synergistic interaction between permeable Ni(OH)2 layer and strained Pt atoms can significantly promote the H2O dissociation and the H2 formation. This electrochemical self-reconstruction method provides an effective and facile strategy for optimizing the electronic structure, electrocatalytic activity, and mass activity of active Pt atoms to develop efficient Pt-based heterostructure electrocatalysts.

Heterostructured electrocatalysts for the oxygen evolution reaction

This review focuses mainly on the overall facilitating effect of heterostructures on the OER process. The fabrication of heterostructured electrocatalysts and the relationship between their structures and electrocatalytic properties are discussed.

Hierarchical FeCo LDH/NiSe heterostructure electrocatalysts with rich heterointerfaces for robust water splitting at industrial-level current density

Sustainable hydrogen production by electrocatalytic water splitting is a promising energy storage technology yet challenging due to the sluggish kinetics of the oxygen evolution reaction (OER). Rationally designed robust and...

Recent advances in transition metal phosphide-based heterostructure electrocatalysts for the oxygen evolution reaction

This paper reviews the recent advances in transition metal phosphide-based heterostructure electrocatalysts for the oxygen evolution reaction.

CoP/CoN heterostructural active centers supported on nitrogen carbon nanorod arrays as freestanding high-performance trifunctional electrocatalysts

Freestanding CoP/CoN heterostructure electrocatalysts for zinc–air batteries and water splitting, and the catalytic mechanism was verified based on DFT and experiments.

Co-doped MnS/NiS/Ni3S2 grown in situ on hydrophilic nickel foam for energy-efficient urea-assisted alkaline hydrogen production

The Co-MnS/NiS/Ni3S2/HNF heterostructure electrocatalyst exhibits remarkable catalytic activity and catalytic stability as a self-supported bifunctional electrode for UOR and HER.

Construction of triple heterogeneous interfaces optimizing electronic structure with B-doped amorphous CoP deposited on crystalline Cu2S/Ni3S2 nanosheets to enhance water electrolysis

Triple heterostructure electrocatalysts CoPB@Cu2S/Ni3S2 with optimized electronic structure and geometry, showing competitive catalytic performance for the HER and OER.

Ir nanoparticles decorated NiFe metal–organic framework as a highly efficient and stable heterostructure electrocatalyst for overall seawater splitting

Ir nanoparticle decorated NiFe metal–organic framework on Ni foam (Ir@NiFe-MOF/NF) acts as a bifunctional catalyst for the oxygen evolution reaction and the hydrogen evolution reaction in alkaline seawater with excellent performance and stability.

Synergistic construction of an iron nitride embedded graphitic carbon nitride heterostructure electrocatalyst as a potential candidate to accelerate overall water electrolysis

A synergistic construction of an iron nitride embedded graphitic carbon nitride heterostructured electrocatalyst via the solid-state pyrolysis method explores potential bifunctional activity towards overall water splitting.

Three-dimensional self-supporting micro-nanostructured MoS2/CoS2/CC heterojunction derived from ZIF-67 for high efficiency electrocatalytic hydrogen evolution in both acid and alkali electrolytes

In this paper, a novel three-dimensional (3D) MoS2/CoS2 micro-nano heterostructured electrocatalyst has been successfully derived from ZIF-67 on carbon cloth (CC) by a simple method of low temperature vulcanization. The metal-organic framework (MOFs) of ZIF-67 on CC was obtained at room temperature and used as both the precursor of Co and structure template to construct the 3D self-supporting spindle CoS2 nanodiscs on CC. Large amounts of 2D MoS2 nanosheets were subsequently grown on the surface of spindle-shaped CoS2 nanodiscs to form 3D self-supporting MoS2/CoS2/CC heterostructural electrocatalyst. This 3D self-supporting heterostructural electrocatalyst showed good hydrogen evolution reaction (HER) performance in both acid and alkali electrolytes. At 10 mA/cm2, the HER overpotentials of the MoS2/CoS2/CC heterostructural electrocatalyst in the alkali and acid electrolyte were 147 mV and 119 mV, and their corresponding Tafel slopes were 90.5 mV dec−1 and 111.4 mV dec−1, respectively, indicating that this MoS2/CoS2/CC heterostructural electrocatalyst had a good application prospect in the electrolysis of water to produce hydrogen. Moreover, this work provides a new idea for low-cost, scale fabrication of 3D self-supporting heterostructured transition metal sulfide catalysts.

An efficient heterostructure MoP2-CoMoP-NC electrocatalyst derived from ZIF-67 for hydrogen evolution reaction

The fabrication of heterostructure electrocatalysts is an effective method for optimizing catalytic activity and improving electrocatalytic performance. Herein, we designed a novel MoP2-CoMoP-NC heterostructure electrocatalyst derived from ZIF-67. The prepared MoP2-CoMoP-NC displays wheat-spike nanorods cross-linked with each other for providing a large electrochemically active surface area. Furthermore, the nitrogen-doped carbon framework derived from ZIF-67 successfully wrapped nanoparticles, which is advantageous for enhancing the stability and conductivity of the catalyst. The heterointerface between MoP2 and CoMoP facilitates mass transport and charge transfer. The MoP2-CoMoP-NC/NF heterostructure electrocatalyst shows enhanced electrocatalytic activity, with a relatively low overpotential of 88.2 mV at 10 mA cm−2 for the hydrogen evolution in alkaline conditions and a Tafel slope of only 65.9 mV dec−1. Furthermore, long-term measurements showed that MoP2-CoMoP-NC/NF has superior durability in alkaline solutions.

Construction of core‐shell heterostructured MnO@Co/NC for enhancing the oxygen electrocatalytic performance

AbstractThe development of non‐precious metal electrocatalysts for efficient oxygen reduction reaction (ORR) is a significant research field vital for the progress of zinc−air battery technology. Here, we purposely constructed a core‐shell heterostructured electrocatalyst consisting of MnO nanotubes covered by Co nanoparticles anchored on N‐doped carbon substrate. MnO@Co/NC displayed superior ORR capability with a half‐wave potential of 0.85 V and almost no potential decay after 10,000 cycles CV test, outform that of commercial Pt/C catalysts. Employing MnO@Co/NC as the air electrode catalyst in primary Zn−air batteries leads to a top power density of 145 mW cm−2 and an enhanced specific capacity of 869 mAh g−1 as compared to commercial noble metal catalysts. Such superb ORR performance outcomes primarily stem from the synergistic effect between Co/NC shell and MnO core since the coupling structure not only regulates the inherent electronic structure but also accelerates electron transfer speed and boosts the active sites. Besides, the Co/NC outer layer can also help to improve the corrosion resistance of MnO@Co/NC in the electrolyte. This work demonstrated that the core‐shell heterostructured non‐precious catalysts open up a new avenue for obtaining sufficiently effective ORR catalysts in Zn−air batteries and other related applications.

Manganese-Doped Bimetallic (Co,Ni)2P Integrated CoP in N,S Co-Doped Carbon: Unveiling a Compatible Hybrid Electrocatalyst for Overall Water Splitting.

Rational design of highly efficient noble-metal-unbound electrodes for hydrogen and oxygen production at increased current density is crucial for robust water-splitting. A facile hydrothermal and room-temperature aging method is presented, followed by chemical vapor deposition (CVD), to create a self-sacrificed hybrid heterostructure electrocatalyst. This hybrid material, (Mn-(Co,Ni)2P/CoP/(N,S)-C), comprises manganese-doped cobalt nickel phosphide (Mn-(Co,Ni)2P) nanofeathers and cobalt phosphide (CoP) nanocubes embedded in a nitrogen and sulfur co-doped carbon matrix (N,S)-C on nickel foam. The catalyst exhibits excellent performance in both the hydrogen evolution reaction (HER; η10 = 61mV) and oxygen evolution reaction (OER; η10 = 213mV) due to abundant active sites, high porosity, and enhanced hetero-interface interaction between Mn-(Co2P-Ni2P) CoP, and (N,S)-C supported by significant synergistic effects observed among different phases through density functional theory (DFT) calculations. Impressively, (Mn-(Co,Ni)2P/CoP/(N,S)-C (+,-) shows an extra low cell voltage of 1.49 V@10mA cm-2. Moreover, the catalyst exhibits remarkable stability at 100 and 300mA cm-2 when operating as a single stack cell electrolyzer. The superior electrochemical activity is attributed to the enhanced electrode-electrolyte interface among the multiple phases of the hybrid structure.

Hydrothermal synthesis of Er2O3–NiO material for oxidation of water in alkaline media

Developing heterostructure electrocatalysts is a possible route to discovering cost-effective and effectual catalysts for the oxygen evolution reaction. Er2O3–NiO nanoparticles have been created by successive drop cost method on nickel form. The produced Er2O3, NiO, and Er2O3–NiO electrocatalytic performances have been assessed, showing increased OER (185 mV@10 mA/cm2) activities compared to the single component. Furthermore, the three-electrode system (Er2O3–NiO) has remarkable OER properties, requiring only 1.37 V to reach 10 mA/cm2. Er2O3–NiO ‘s synergistic effect, which helps to cause lattice change into the fine structure of the crystal, activates the evolution of surface partial oxygen atoms and enables the lattice oxygen process, is principally responsible for its excellent catalytic performance and stability. This research contributes to a more profound knowledge of the synergistic interaction between various material oxides in heterostructure catalysts. It offers recommendations for future research and development of nanomaterials in sustainable energy conversion technologies.

In-situ construction defect-rich CuNiCoS4 /1T-MoS2 heterostructures as superior electrocatalysts for water splitting

Rational design and construction of bifunctional heterostructure electrocatalysts with high-conductivity and more active sites is imperative for water splitting. Herein, based on the tunable property of layered double hydroxide laminates cations, topological transformation technology and template confine method, a series of high-performance bifunctional catalysts composed of transition metal doping NiCo2S4 (MNiCoS4, M = Cu, Fe, Zn, Mn) and 1T-MoS2 were in-situ fabricated on nickel foam. In particular, CuNiCoS4/1T-MoS2 exhibits an ultralow overpotential of 163 mV at 50 mA cm−2 for oxygen evolution reaction (OER) and favorable hydrogen evolution reaction activity. The two-electrode system requires only 1.52 V to attain a current density of 10 mA cm−2. To the best of our knowledge, its OER electrocatalytic activity far exceed state-of-art catalysts reported. The outstanding performance of this series of catalysts can be attributed to two aspects. First, the highly conductive 1T-MoS2 can facilitate electron transfer, and second, the defect-rich heterostructure can effectively regulate the electronic structure of the active metal and expose abundant active sites. This work provides a valuable strategy for developing high activity electrocatalysts for efficient water splitting.

Fe regulating Ni3S2/ZrCoFe-LDH@NF heterojunction catalysts for overall water splitting

With the continuous depletion of traditional energy sources, the development of sustainable energy sources has become one of the important tasks today. A two-step synthesis method was employed to construct Ni3S2/ZrCoFe-LDH@NF heterostructured electrocatalysts on nickel foam (NF) in situ. X-ray diffractometer, scanning electron microscope, transmission electron microscope, and X-ray electron spectroscopy were employed to characterize the Ni3S2/ZrCoFe-LDH@NF heterostructure, and the hydrogen-extraction reaction (HER), oxygen-extraction reaction (OER) and total hydrolysis properties of this electrocatalyst were tested in 1 mol·L−1 KOH electrolyte. It is shown that Ni3S2/ZrCoFe-LDH@NF is a lamellar stacked heterostructure with an overpotential of 330 mV and a Tafel slope of 90.9 mV·dec−1 at a current density of 100 mA·cm−2 in the OER reaction and 159.2 mV at a current density of 10 mA·cm−2 in the HER reaction. The Tafel slope is 96 mV·dec−1, and the catalyst exhibits good structural stability in the 100 h total hydrolysis stability test. The successful construction of this heterostructured electrocatalyst provides a good idea and research basis for the subsequent heterojunction and its application in electrocatalysis.

Molten-Salt Electrochemical Preparation of Co2B/MoB2 Heterostructured Nanoclusters for Boosted pH-Universal Hydrogen Evolution.

Boosting the hydrogen evolution reaction (HER) activity of α-MoB2 at large current densities and in pH-universal medium is significant for efficient hydrogen production. In this work, Co2B/MoB2 heterostructured nanoclusters are prepared by molten-salt electrolysis (MSE) and then used as a HER catalyst. The composition, structure, and morphology of Co2B/MoB2 can be modulated by altering the stoichiometries of raw materials and synthesis temperatures. Impressively, the obtained Co2B/MoB2 at optimized conditions exhibits a low overpotential of 297 and 304mV at 500mA cm-2 in 0.5m H2SO4 and 1m KOH, respectively. Moreover, the Co2B/MoB2 catalyst possesses a long-term catalytic stability of over 190h in both acidic and alkaline medium. The excellent HER performance is due to the modified electronic structure at the Co2B/MoB2 heterointerface where electrons are accumulated at the Mo sites to strengthen the H adsorption. Density functional theory (DFT) calculations reveal that the formation of the Co2B/MoB2 heterointerface decreases the H adsorption and H2O dissociation free energies, contributing to the boosted HER intrinsic catalytic activity of Co2B/MoB2. Overall, this work provides an experimental and theoretical paradigm for the design of efficient pH-universal boride heterostructure electrocatalysts.

An oxygen-vacancy-boosted heterostructured catalyst with synergistically integrated dual transition-metal oxides for high-performance lithium-sulfur batteries

The practical use of high-energy–density Li–S batteries (LSBs) is significantly hampered by the severe dissolution of soluble Li polysulfides (LiPSs) and their sluggish redox kinetics. To address these issues, a novel heterostructured electrocatalyst comprising nano-RuO2-decorated hexagonal CeO2 (NRHC) was developed in this study. The hetero-growth of RuO2 on the plate-shaped HC induced beneficial oxygen vacancies (OVs), which provided positively charged sites and free electrons owing to the lattice disorder between RuO2 and CeO2, thereby boosting the ability of the NRHC to adsorb LiPSs, exhibit enhanced conversion kinetics, and facilitate Li+ transport. Moreover, the NRHC heterostructure comprising RuO2 (a polar but highly conductive material) and CeO2 (a polar and surface-OV-rich material) effectively improved the “trapping–diffusion–conversion” process to transform LiPSs into Li2S on its surface. Benefiting from the synergistic catalytic attributes of the NRHC, an LSB with the NRHC-modified separator exhibited superior cyclability (844.7 mAh/g after 1000 cycles with a low-capacity decay rate of 0.029% per cycle) at a high current density of 1 C. Even at a high sulfur loading (6.4 mg cm−2), the LSB achieved a high areal capacity of over 4.5 mAh cm−2 at 0.1 C, highlighting its practical applicability.