Reaction Packaging CoSe2 Nanoparticles in N-Doped Carbon Polyhedra with Bifunctionality for Overall Water Splitting

Local electronic structure engineering of vanadium-doped nickel phosphide nanosheet arrays for efficient hydrogen evolution

Local electronic structure engineering is an effective approach for optimizing the catalytic performance of electrocatalysts. Herein, a dual-phase vanadium-doped nickel phosphide (NiVxP) catalyst supported on nickel foam (NF) was synthesized via a successive hydrothermal and phosphorization process with interconnected nanosheet structures and homogeneous distributions. The catalyst's stable phase and strong adhesion to the substrate ensure good electrochemical stability. The incorporation of V effectively promotes initial H2O adsorption and H* formation, leading to a lower overpotential. As a result, the fabricated NiVxP@NF demonstrates favorable hydrogen evolution reaction (HER) activity and stability, with only 85 mV overpotential needed to reach 10 mA·cm-2 and showing no significant increase in the overpotential during the long-term 78-hour stability test.

Interfacial Electronic Engineering of NiSe–Anchored Ni–N–C Composite Electrocatalyst for Efficient Hydrogen Evolution

Rational design and construction of cost–effective electrocatalysts for efficient hydrogen production has attracted extensive research attention worldwide. Herein, we report the construction of a transition metal selenide/carbon composite catalyst featuring uniform NiSe nanoparticles anchored to single Ni atom doped porous carbon structure (NiSe/Ni–N–C) via a facile one–pot pyrolysis of low–cost solid mixtures. NiSe/Ni–N–C exhibits remarkable catalytic performance towards hydrogen evolution reaction (HER) in 1.0 M KOH, requiring a low overpotential of 146 mV to reach a current density of 10 mA cm−2. The unique carbon layer encapsulation derived from the enwrapping of fluid catalytic cracking slurry further renders NiSe/Ni–N–C excellent for long–term durability in electrolyte corrosion and nanostructure aggregation. This work paves the way for the design and synthesis of highly efficient composite HER electrocatalysts.

Zeolite Imidazolate Frameworks (ZIFs) Derived Nanomaterials and their Hybrids for Advanced Secondary Batteries and Electrocatalysis

Zeolite imidazolate frameworks (ZIFs), as a typical class of metal-organic frameworks (MOFs), have attracted a great deal of attention in the field of energy storage and conversation due to their chemical structure stability, facile synthesis and environmental friendliness. Among of ZIFs family, the zinc-based imidazolate framework (ZIF-8) and cobalt-based imidazolate framework (ZIF-67) have considered as promising ZIFs materials, which attributed to their tunable porosity, stable structure, and desirable electrical conductivity. To date, various ZIF-8 and ZIF67 derived materials, including carbon materials, metal oxides, sulfides, selenides, carbides and phosphides, have been successfully synthesized using ZIFs as templates and evaluated as promising electrode materials for secondary batteries and electrocatalysis. This review provides an effective guide for the comprehension of the performance optimization and application prospects of ZIFs derivatives, specifically focusing on the optimization of structure and their application in secondary batteries and electrocatalysis. In detail, we present recent advances in the improvement of electrochemical performance of ZIF-8, ZIF-67 and ZIF-8@ZIF-67 derived nanomaterials and their hybrids, including carbon materials, metal oxides, carbides, oxides, sulfides, selenides, and phosphides for high-performance secondary batteries and electrocatalysis.

In Situ Growth of NiSe2-MoSe2 Heterostructures on Graphene Nanosheets as High-Performance Electrocatalyst for Hydrogen Evolution Reaction

Developing highly efficient and stable electrocatalysts for hydrogen evolution reaction (HER) is regarded as a crucial way to reduce energy loss in water splitting. Herein, NiSe2/MoSe2 heterostructures grown on graphene nanosheets (NiSe2-MoSe2 HTs/G) have been in situ synthesized by a simple hydrothermal reaction. As an electrocatalyst for HER, NiSe2-MoSe2 HTs/G delivers superior performance with a low Tafel slope of 65 mV dec−1, a small overpotential of 144 mV at 10 mA cm−2, and long-term stability up to 24 h. The superior performance for HER can be mainly ascribed to the synergistic effects of NiSe2-MoSe2 heterostructures, which can facilitate the rapid electron transfer from the electrode to the exposed MoSe2 edges to take part in the HER reaction, thus boosting the HER kinetics. Moreover, the graphene matrix with high conductivity can not only improve the overall conductivity of the composite but also greatly increase the exposed active sites, therefore further promoting the HER performance. This study provides a simple route for fabricating bimetallic selenides-based heterostructures on graphene as an efficient and stable electrocatalyst for HER.

In situ construction of FeNi2Se4-FeNi LDH heterointerfaces with electron redistribution for enhanced overall water splitting

The abundant heterogeneous interfaces between the FeNi2Se4 and FeNi LDH can provide enriched active sites and accelerate reaction kinetics, which improves the overall water splitting performance.

Robust NiCoP@FeP derived from Prussian blue analog for efficient overall water splitting

The design of efficient, stable, and non-noble metal based bifunctional electrocatalysts remains a great challenge. The synergistic effect can adjust the local electronic structure to improve the catalytic performance. In...

Cobalt metal organic framework (Co-MOF) derived CoSe2/C hybrid nanostructures for the electrochemical hydrogen evolution reaction supported by DFT studies

Through a single step and facile approach, CoSe2/C is synthesized from a HER inactive pristine MOF without adding any external carbon source, which efficiently catalyses HER in acidic medium which was also supported by DFT studies.

Hierarchical CoFe LDH/MOF nanorods array with strong coupling effect grown on carbon cloth enables efficient oxidation of water and urea

Oxygen evolution reaction (OER) and urea oxidation reaction (UOR) play important roles in the fields of hydrogen energy production and pollution treatment. Herein, a facile one-step chemical etching strategy is provided for fabricating one-dimensional hierarchical nanorods array composed of CoFe layered double hydroxide (LDH)/metal-organic frameworks (MOFs) supported on carbon cloth as efficient and stable OER and UOR catalysts. By precisely controlling the etching rate, the ligands from Co-MOFs are partially removed, the corresponding metal centers then coordinate with hydroxyl ions to generate ultrathin amorphous CoFe LDH nanosheets. The resultant CoFe LDH/MOFs catalyst possesses large active surface area, enhanced conductivity and extended electron/mass transfer channels, which are beneficial for catalytic reactions. Additionally, the intimate contact between CoFe LDH and MOFs modulates the local electronic structure of the catalytic active site, leading to enhanced adsorption of oxygen-containing intermediates to facilitate fast electrocatalytic reaction. As a result, the optimized CoFe LDH/MOF-0.06 exhibits superior OER activity with a low overpotential of 276 at a current density of 10 mA cm^-2with long-term durability. Additionally, it merely requires a voltage of 1.45 V to obtain 10 mA cm^-2in 1 M KOH solution with 0.33 urea and is 56 mV lower than the one in pure KOH. The work presented here may hew out a brand-new route to construct multi-functional electrocatalysts for water splitting, CO₂reduction, nitrogen reduction reactions and so on.

Designing MOF Nanoarchitectures for Electrochemical Water Splitting

Electrochemical water splitting has attracted significant attention as a key pathway for the development of renewable energy systems. Fabricating efficient electrocatalysts for these processes is intensely desired to reduce their overpotentials and facilitate practical applications. Recently, metal-organic framework (MOF) nanoarchitectures featuring ultrahigh surface areas, tunable nanostructures, and excellent porosities have emerged as promising materials for the development of highly active catalysts for electrochemical water splitting. Herein, the most pivotal advances in recent research on engineering MOF nanoarchitectures for efficient electrochemical water splitting are presented. First, the design of catalytic centers for MOF-based/derived electrocatalysts is summarized and compared from the aspects of chemical composition optimization and structural functionalization at the atomic and molecular levels. Subsequently, the fast-growing breakthroughs in catalytic activities, identification of highly active sites, and fundamental mechanisms are thoroughly discussed. Finally, a comprehensive commentary on the current primary challenges and future perspectives in water splitting and its commercialization for hydrogen production is provided. Hereby, new insights into the synthetic principles and electrocatalysis for designing MOF nanoarchitectures for the practical utilization of water splitting are offered, thus further promoting their future prosperity for a wide range of applications.

Cobalt-Based Metal-Organic Frameworks and Their Derivatives for Hydrogen Evolution Reaction

Hydrogen has been considered as a promising alternative energy to replace fossil fuels. Electrochemical water splitting, as a green and renewable method for hydrogen production, has been drawing more and more attention. In order to improve hydrogen production efficiency and lower energy consumption, efficient catalysts are required to drive the hydrogen evolution reaction (HER). Cobalt (Co)-based metal-organic frameworks (MOFs) are porous materials with tunable structure, adjustable pores and large specific surface areas, which has attracted great attention in the field of electrocatalysis. In this review, we focus on the recent progress of Co-based metal-organic frameworks and their derivatives, including their compositions, morphologies, architectures and electrochemical performances. The challenges and development prospects related to Co-based metal-organic frameworks as HER electrocatalysts are also discussed, which might provide some insight in electrochemical water splitting for future development.

Metal-Organic Framework-Derived Fe-Doped Co1.11 Te2 Embedded in Nitrogen-Doped Carbon Nanotube for Water Splitting

A rational design is reported of Fe-doped cobalt telluride nanoparticles encapsulated in nitrogen-doped carbon nanotube frameworks (Fe-Co_1.11 Te₂ @NCNTF) by tellurization of Fe-etched ZIF-67 under a mixed H₂ /Ar atmosphere. Fe-doping was able to effectively modulate the electronic structure of Co_1.11 Te₂ , increase the reaction activity, and further improve the electrochemical performance. The optimized electrocatalyst exhibited superior hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performances in an alkaline electrolyte with low overpotentials of 107 and 297 mV with a current density of 10 mA cm^-2 , in contrast to the undoped Co_1.11 Te₂ @NCNTF (165 and 360 mV, respectively). The overall water splitting performance only required a voltage of 1.61 V to drive a current density of 10 mA cm^-2 . Density function theory (DFT) calculations indicated that the Fe-doping not only afforded abundant exposed active sites but also decreased the hydrogen binding free energy. This work provided a feasible way to study non-precious-metal catalysts for an efficient overall water splitting.

Cobalt-based heterogeneous catalysts in an electrolyzer system for sustainable energy storage

Nowadays, the production of hydrogen and oxygen focuses on renewable energy techniques and sustainable energy storage. A substantial challenge is to extend low-cost electrocatalysts consisting of earth-abundant resources, prepared by straightforward approaches that display high intrinsic activity compared to noble metals. The expansion of bifunctional catalysts in alkaline electrolytes for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) has become very crucial in recent times. Herein, the recent progress in cobalt-based HER-OER electrocatalysts has been are brushed up and numerous bifunctional cobalt-based catalysts such as cobalt-oxides, phosphides, sulfides, selenides, nitrides, borides, carbides, perovskites, and MOF-based cobalt analogs have been investigated in detail. Specifically, much more attention has been paid to their structural variation, bifunctional activity, overpotential of the overall system, and stability. Cobalt-based catalysts with lower cell voltage, remarkable durability, and unique electronic structures, offer a new perspective in energy-related fields. In recent years, cobalt-based analogs with diagnostic facilities have been introduced due to their electronic structures, tunable d band structures, and tailorable active sites. This perspective also elucidates the present issues, promising ideas, and future forecasts for cobalt-based catalysts. The critical aspects of cobalt-based catalysts and the numerous opportunities, as discussed at the end, can possibly enrich the sustainable energy field.

Solvent-Exchange Strategy toward Aqueous Dispersible MoS2 Nanosheets and Their Nitrogen-Rich Carbon Sphere Nanocomposites for Efficient Lithium/Sodium Ion Storage

Major challenges in developing 2D transition-metal disulfides (TMDs) as anode materials for lithium/sodium ion batteries (LIBs/SIBs) lie in rational design and targeted synthesis of TMD-based nanocomposite structures with precisely controlled ion and electron transport. Herein, a general and scalable solvent-exchange strategy is presented for uniform dispersion of few-layer MoS₂ (f-MoS₂ ) from high-boiling-point solvents (N-methyl-2-pyrrolidone (NMP), N,N-dimethyl formaldehyde (DMF), etc.) into low-boiling-point solvents (water, ethanol, etc.). The solvent-exchange strategy dramatically simplifies high-yield production of dispersible MoS₂ nanosheets as well as facilitates subsequent decoration of MoS₂ for various applications. As a demonstration, MoS₂ -decorated nitrogen-rich carbon spheres (MoS₂ -NCS) are prepared via in situ growth of polypyrrole and subsequent pyrolysis. Benefiting from its ultrathin feature, largely exposed active surface, highly conductive framework and excellent structural integrity, the 2D core-shell architecture of MoS₂ -NCS exhibits an outstanding reversible capacity and excellent cycling performance, achieving high initial discharge capacity of 1087.5 and 508.6 mA h g^-1 at 0.1 A g^-1 , capacity retentions of 95.6% and 94.2% after 500 and 250 charge/discharge cycles at 1 A g^-1 , for lithium/sodium ion storages, respectively.

CoSe2/porous carbon shell composites as high-performance catalysts toward tri-iodide reduction in dye-sensitized solar cells

CoSe₂/carbon shell composites with many active sites were developed as catalysts for I₃⁻ reduction in dye-sensitized solar cells with efficiency and stability exceeding those of Pt.