Metal Selenides Research Articles

Recent Progress of Transition Metal Selenides for Electrochemical Oxygen Reduction to Hydrogen Peroxide: From Catalyst Design to Electrolyzers Application.

Hydrogen peroxide (H2O2) is a highly value-added and environmental-friendly chemical with various applications. The production of H2O2 by electrocatalytic 2e- oxygen reduction reaction (ORR) has emerged as a promising alternative to the energy-intensive anthraquinone process. High selectivity Catalysts combining with superior activity are critical for the efficient electrosynthesis of H2O2. Earth-abundant transition metal selenides (TMSs) being discovered as a classic of stable, low-cost, highly active and selective catalysts for electrochemical 2e- ORR. These features come from the relatively large atomic radius of selenium element, the metal-like properties and the abundant reserves. Moreover, compared with the advanced noble metal or single-atom catalysts, the kinetic current density of TMSs for H2O2 generation is higher in acidic solution, which enable them to become suitable catalyst candidates. Herein, the recent progress of TMSs for ORR to H2O2 is systematically reviewed. The effects of TMSs electrocatalysts on the activity, selectivity and stability of ORR to H2O2 are summarized. It is intended to provide an insight from catalyst design and corresponding reaction mechanisms to the device setup, and to discuss the relationship between structure and activity.

Comparative performance of single and binary metal selenides in dye-sensitized solar cells

Comparative performance of single and binary metal selenides in dye-sensitized solar cells

Copper–Iron Selenides Nanoflakes and Carbon Nanotubes Composites as an Advanced Anode Material for High‐Performance Lithium‐Ion Batteries

Metal selenides are widely considered as an emerging anode electrode material for lithium‐ion batteries (LIBs). Hence, the present study uses a conductive carbon materials matrix such as carbon nanotubes (CNTs) with copper–iron selenide (CuFeSe2). The composites (CuFeSe2@CNTs) are synthesized by a hydrothermal method and examined for electrochemical performance as anode applications in LIBs. Herein, the CuFeSe2@CNTs show excellent specific capacity of 783.7 and 720.6 mA h g−1 at 0.1 and 1 A g−1, respectively. This composite further exhibits a high‐capacity value compared to only FeSe2 and CuFeSe2 and a reversible capacity of 691 mA h g−1 after 200 cycles at 1 A g−1 current density. Moreover, the homogeneous combination of CuFeSe2 nanoflakes and CNTs provides structural stability that reduces the volume change during lithium‐ion interactions and successively improves the conductivity of the complex, which is advantageous for better ion and electron kinetics during the reaction.

MOF-Derived Bimetallic Selenide CoNiSe2 Nanododecahedrons Encapsulated in Porous Carbon Matrix as Advanced Anodes for Lithium-Ion Batteries.

Transition metal selenides have received considerable attention as promising candidates for lithium-ion battery (LIB) anode materials due to their high theoretical capacity and safety characteristics. However, their commercial viability is hampered by insufficient conductivity and volumetric fluctuations during cycling. To address these issues, we have utilized bimetallic metal-organic frameworks to fabricate CoNiSe2/C nanodecahedral composites with a high specific surface area, abundant pore structures, and a surface-coated layer of the carbon-based matrix. The optimized material, CoNiSe2/C-700, exhibited impressive Li+ storage performance with an initial discharge specific capacity of 2125.5 mA h g-1 at 0.1 A g-1 and a Coulombic efficiency of 98% over cycles. Even after 1000 cycles at 1.0 A g-1, a reversible discharge specific capacity of 549.9 mA h g-1 was achieved. The research highlights the synergistic effect of bimetallic selenides, well-defined nanodecahedral structures, stable carbon networks, and the formation of smaller particles during initial cycling, all of which contribute to improved electronic performance, reduced volume change, increased Li+ storage active sites, and shorter Li+ diffusion paths. In addition, the pseudocapacitance behavior contributes significantly to the high energy storage of Li+. These features facilitate rapid charge transfer and help maintain a stable solid-electrolyte interphase layer, which ultimately leads to an excellent electrochemical performance. This work provides a viable approach for fabricating bimetallic selenides as anode materials for high-performance LIBs through architectural engineering and compositional tailoring.

Rational design of metal selenides nanomaterials for alkali metal ion (Li+/Na+/K+) batteries: current status and perspectives

Rational design of metal selenides nanomaterials for alkali metal ion (Li+/Na+/K+) batteries: current status and perspectives

A hollow Double-Shell CoSe2@Carbon hybrid for High-Performance electrochemical sodium storage

Designing an intelligent metal selenides/carbon hybrid assembly is considered to be a very feasible strategy to maximize the potential of metal selenides and carbon materials for electrochemical Na+ storage. Herein, we prepare a hollow double-shell Co-MOF-74-derived CoSe2@carbon hybrid in which plenty of ultrafine CoSe2 nanoparticles are encapsulated within carbon matrix, and such a unique CoSe2@carbon hybrid is able to take advantages of both hollow double-shell structure and plum pudding-like structure, which facilitate fast electrochemical kinetics and high tolerance to volumetric strain. As a result, the prepared hollow double-shell CoSe2@carbon hybrid exhibits a reversible capacity of 223.4 mAh/g at a very high current density of 10 A/g for Na+ storage, and also holds 92.3 % of capacity retention after 5000 cycles at 2 A/g. This work has provided a useful enlightenment for developing high-efficiency electrode materials in the electrochemical Na+ storage field.

Interfacial-Confined Isochronous Conversion to Biphasic Selenide Heterostructure with Enhanced Adsorption Behaviors for Robust High-Rate Na-Ion Storage.

Sodium-ion batteries (SIBs) have gradually become one of the most promising energy storage techniques in the current era of post-lithium-ion batteries. For anodes, transitional metal selenides (TMSe) based materials are welcomed choices , owing to relatively higher specific capacities and enriched redox active sites. Nevertheless, current bottlenecks are blamed for their poor intrinsic electronic conductivities, and uncontrollable volume expansion during redox reactions. Given that, an interfacial-confined isochronous conversion strategy is proposed, to prepare orthorhombic/cubic biphasic TMSe heterostructure, namely CuSe/Cu3 VSe4 , through using MXene as the precursor, followed by Cu/Se dual anchorage. As-designed biphasic TMSe heterostructure endows unique hierarchical structure, which contains adequate insertion sites and diffusion spacing for Na ions, besides, the surficial pseudocapacitive storage behaviors can be also proceeded like 2D MXene. By further investigation on electronic structure, the theoretical calculations indicate that biphasic CuSe/Cu3 VSe4 anode exhibits well-enhanced properties, with smaller bandgap and thus greatly improves intrinsic poor conductivities. In addition, the dual redox centers can enhance the electrochemical Na ions storage abilities. As a result, the as-designed biphasic TMSe anode can deliver a reversible specific capacity of 576.8mAhg-1 at 0.1Ag-1 , favorable Na affinity, and reduced diffusion barriers. This work discloses a synchronous solution toward demerits in conductivities and lifespan, which is inspiring for TMSe-based anode development in SIBs systems.

NiSe-modified CoMoO4 nanosheets as bifunctional electrocatalysts for hydrogen and oxygen evolution reactions

Selecting self-supporting substrates with large specific surface areas is an effective strategy to avoid the agglomeration of nanomaterials and improve the structural stability of materials while increasing their electrical conductivity. In this study, CoMoO4 nanosheet structures were first grown on a nickel foam (NF) substrate by hydrothermal and calcination processes. Then, NiSe nanoparticles were deposited on NF/CoMoO4 by a constant potential method to construct NF/CoMoO4 @NiSe nanosheet electrode materials with graded layered structures. This nanosheet structure grown on NF substrates provided enough space for mass transfer and fully exposed the electrochemical active sites. Meanwhile, the self-supported electrode reduced the indirect contact resistance between the electrocatalyst and the substrate, which promoted the timely release of generated bubbles from the electrode. The NF/CoMoO4 @NiSe electrode exhibited excellent hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) electrocatalytic activities under alkaline conditions. Overpotentials of only 58 mV and 184 mV were needed to achieve a current density of 10 mA·cm−2 for the HER and OER, respectively. This study presents new ideas for the construction of nanosheet structures and the design of efficient HER and OER bifunctional electrocatalysts using transition metal selenides.

Bimetallic NiCo2Se4/Fe2CoSe4 chrysanthemum flowers assembled by nanosheets: An efficient electrode material for hybrid supercapacitor applications

Transition metal selenides have excellent promise for high-performance electrode materials owing to their great electrical conductivity and theoretical capacity. Unfortunately, the electrochemical performance of single-metal selenides is undesirable because of their low energy density and poor cyclic stability, and one practical approach is to introduce heteroatoms to create bimetallic selenides. Herein, a novel bimetallic NiCo2Se4/Fe2CoSe4 chrysanthemum flower assembled by nanosheets on NiF was synthesized via a hydrothermal process as a binder-free electrode for a hybrid supercapacitor. Because of the presence of plentiful redox active sites, unique architecture with large surface area and mesoporous channels, desirable electrical conductivity, and synergistic effect of Ni, Co, and Fe, the bimetallic NiCo2Se4/Fe2CoSe4 electrode material shows significantly increased electrochemical performance. Interestingly, the bimetallic NiCo2Se4/Fe2CoSe4 electrode material shows an outstanding specific capacity of 323.66 mAhg−1 (1175.97 Cg−1) at 1 Ag−1, retaining 91.08% of the initial capacity at 20 Ag−1, with long-lasting cyclic stability of 91.08% after 10,000 GCD cycles at 20 Ag−1. A binder-free bimetallic NiCo2Se4/Fe2CoSe4 @NiF electrode's outstanding electrochemical efficiency can be related to the existence of two bimetallic selenides, and beneficial interaction, which yields quick charge transfer reactions. Moreover, the NiCo2Se4/Fe2CoSe4@NiF//AC@NiF hybrid supercapacitor by bimetallic NiCo2Se4/Fe2CoSe4@NiF (positive electrode) and activated carbon (AC@NiF, negative electrode) displayed specific energy which is 51.83 Whkg−1 at 749.83 Wkg−1 and 34.2 Whkg−1 at 14996.34 Wkg−1 at 20 Ag−1 and superior stability of 92.33% after 10,000 GCD cycles. This research provides some insight into the design of an electrode material with a flower-like decorated with nanosheets morphology for hybrid supercapacitors.

Modulating electronic structure of nickel diselenide by vanadium doping toward highly efficient and stable bifunctional electrocatalysts for overall water splitting

Designing low-cost and high-efficiency bifunctional electrocatalysts is one of the challenges in the clean production of hydrogen energy in electrochemical water splitting. Transition metal selenides (TMSes) have been widely studied because of their low price, intrinsic metal properties, and high catalytic activity. In addition, the synergistic effect between bimetallic selenides exhibits better performance than monometallic selenides in the electrocatalytic process. Herein, we synthesized V-doped NiSe2 nanowire arrays on pretreated nickel foam by a convenient two-step hydrothermal synthesis method. In the alkaline electrolyte, V-NiSe2/NF exhibited excellent OER catalytic activity (293.6 mV@50 mA cm–2). In addition, the introduction of heteroatom V induces stronger electronic interactions between the structural atoms of the catalyst, altering the electronic structure and causing V-NiSe2/NF to demonstrate excellent OER performance. In the long-term OER test, V-NiSe2/NF was converted into NiOOH and SeOx2–, which may be the “real” active species during catalytic reactions, and we also successfully captured the formation of intermediate NiOOH and selenite as active centers in the OER process through in-situ Raman. The theoretical calculation shows that the electron transfer modulates the electron structure, changes the adsorption-desorption energy of the reaction intermediates, reduces the potential barrier of the rate-limiting step, and improves the OER activity. The V doping engineering strategy and the unique nanowire array structure make TMSes exhibit excellent OER performance. This study provides a new idea for the design of TMSe catalysts with excellent electrocatalytic performance.

Constructing delocalized electronic structures to motivate the oxygen reduction activity of zinc selenide for high-performance zinc-air battery

Rechargeable zinc-air battery (ZAB) typically necessitates highly efficient, durable, and cost-effective electrocatalysts to accelerate oxygen reduction reaction (ORR). Zinc selenide (ZnSe) has been demonstrated as a superior energy storage material due to its unique electronic structure for various energy-related applications but is still rarely developed in electrocatalysis field. Herein, the efficient interfacial engineering is reported to motivate and sufficiently boost the ORR performances of ZnSe to an unprecedented level. Density functional theory (DFT) calculations demonstrate that the introduction of robust Se-C interactions and N species regulation could efficiently modulate the local electronic structure of ZnSe and improve the interaction with oxygen-containing intermediate, thus producing lower reaction energy barrier of O2 → OOH* conversion. The optimized ZnSe@PNC catalyst manifests remarkable ORR activity with a half-wave potential of 0.905 VRHE in alkaline. Furthermore, the assembled Zn-air batteries with ZnSe@PNC cathodes show large peak power density (126 mW cm−2), high specific capacity (818 mAh/g) and long cycling life (200 h). This work provides more possibilities for the electrocatalytic applications of nonprecious metal selenide electrocatalyst for future energy storage.

Cubic CoSe2@carbon as polysulfides adsorption-catalytic mediator for fast redox kinetics and advanced stability lithium-sulfur batteries

Although lithium-sulfur batteries (LSBs) are an attractive next-generation rechargeable battery with high theoretical energy density (2600 Wh kg−1) and specific capacity (1675 mA h g−1), the shuttle of soluble lithium polysulfides (LiPSs) is still the protruding obstacle to accelerate the redox reaction of LSBs. Here, cubic cobalt diselenide@carbon (CoSe2@C) derived from zeolite imidazole framework-67 (ZIF-67) was employed as the functional coating of polypropylene (PP) separator to efficiently adsorb and catalyze polysulfides, inhibit “shuttle effect” and improve the electrochemical reaction kinetics of LSBs. The CoSe2@C offers larger mesopore proportion of 77.19 % and abundant active sites to ensure space as a secondary reaction region, and infiltration of electrolyte and rapid transport of Li+. The involved adsorption and catalysis effect are discussed by static adsorption experiment, XPS, and Li2S nucleation kinetics analysis. The results show that CoSe2@C exhibits strong adsorption effect and catalytic activity on LiPSs, and CoSe2@C/PP cells display fast Li+ diffusion and improved redox kinetics (high Li2S nucleation peak current of 0.27 mA and deposition capacity of 148.46 mA h g−1). Ascribe to these advantages, the CoSe2@C/PP cell provides an initial discharge specific capacity of 1335.01 mA h g−1 at 0.1 C and a fine reversible capacity at 5.0 C, and achieves stable and durable lifespan with an average capacity decay rate of 0.12 % over 400 cycles at 0.5 C. This work could promote the practical application of metal selenides in the key components and devices for LSBs.

ZnSe/SnSe Heterostructure Incorporated with Selenium/Nitrogen Co-Doped Carbon Nanofiber Skeleton for Sodium-Ion Batteries.

Effective strategies toward building exquisite nanostructures with enhanced structural integrity and improved reaction kinetics will carry forward the practical application of alloy-based materials as anodes in batteries. Herein, a free-standing 3D carbon nanofiber (CNF) skeleton incorporated with heterostructured binary metal selenides (ZnSe/SnSe) nanoboxes is developed for Na-ion storage anodes, which can facilitate Na+ ion migration, improve structure integrity, and enhance the electrochemical reaction kinetics. During the carbonization and selenization process, selenium/nitrogen (Se/N) is co-doped into the 3D CNF skeleton, which can improve the conductivity and wettability of the CNF matrices. More importantly, the ZnSe/SnSe heterostructures and the Se/N co-doping CNFs can have a synergistic interfacial coupling effect and built-in electric field in the heterogeneous interfaces of ZnSe/SnSe hetero-boundaries as well as the interfaces between the CNF matrix and the selenide heterostructures, which can enable fast ion/electron transport and accelerate surface/internal reaction kinetics for Na-ion storage. The ZnSe/SnSe@Se,N-CNFs exhibit superior Na-ion storage performance than the comparative ZnSe/SnSe, ZnSe and SnSe powders, which deliver an excellent rate performance (882.0, 773.6, 695.7, 634.2, and 559.0mAhg-1 at current rates of 0.1, 0.2, 0.5, 1, and 2Ag-1) and long-life cycling stability of 587.5mAhg-1 for 3500 cycles at 2Ag-1.

Revolutionizing energy storage with advanced reduced graphene oxide-wrapped MnSe@CoSe@FeSe2 nanowires.

Thanks to their good redox activity properties and exceptional conductivity, metal selenides (MSs) have attracted great attention as prospective positive electrodes for hybrid supercapacitors. However, they demonstrate low-rate capacities and poor endurance. Nanomaterials fabricated from MSs and reduced graphene oxide (rGO) with a porous skeleton can effectively mitigate the above-mentioned problems. Herein, porous MnSe@CoSe@FeSe2 nanowires wrapped with rGO on nickel foam (NF@MCFS-rGO) are manufactured as a binder-free electrode for a hybrid supercapacitor. The obtained NF@MCFS-rGO, acting as a positive electrode, has distinct advantages such as (1) the porous nanowires are helpful for fast electrolyte penetration, (2) the conductivity of the MCFS is further improved when combined with rGO, and (3) wrapping MCFS within the rGO endows the nanomaterial with much better structural durability. Capitalizing on the high conductivity of the rGO and the porous morphology, the fabricated NF@MCFS-rGO manifests impressive characteristics with a capacitance of 1830 F g-1 at 1 A g-1 and only 6.75% capacitance loss within 10 000 cycles. By matching NF@MCFS-rGO with activated carbon (AC), the fabricated apparatus (AC\\NF@MCFS-rGO) reveals an energy density (ED) of 64.6 W h kg-1 and a long lastingness of 90.55% after 10 000 cycles.

Design and construction of hollow metal sulfide/selenide core-shell heterostructure arrays for hybrid supercapacitor.

Transition metal sulfides and selenides are common electrode materials in supercapacitors. However, the slow redox kinetics and structural collapse during charge-discharge cycles of single-component materials have impeded their electrochemical performance. In this study, hollow Co9S8 nanotubes were synthesized through a rational morphology design approach. Subsequently, NiSe2 or Co0.85Se was electrodeposited onto the Co9S8 nanotubes, yielding two core-shell heterostructure arrays, namely, NiSe2@Co9S8 and Co0.85Se@Co9S8. By fully leveraging the advantages and synergistic effects of these dual-phase heterostructures, the NiSe2@Co9S8 and Co0.85Se@Co9S8 configurations demonstrated outstanding areal capacitances of 12.54 F cm-2 and 9.61 F cm-2, respectively, at 2 mA cm-2. When integrated with activated carbon in hybrid supercapacitors, the NiSe2@Co9S8//AC and Co0.85Se@Co9S8//AC devices exhibited excellent energy storage performance, with energy densities of 0.959 mW h at 1.681 mW and 0.745 mW h at 1.569 mW, respectively. Additionally, these hybrid supercapacitors demonstrated remarkable cycling stability, with capacitance retention of 87.5% and 89.5% after 5000 cycles for NiSe2@Co9S8//AC and Co0.85Se@Co9S8//AC, respectively. This study provides a novel approach to the synthesis of multiphase core-shell heterostructures based on metal sulfides and selenides, opening new avenues for future research.

Towards metal selenides: a promising anode for sodium-ion batteries.

Metal selenides have garnered significant attention as promising anode materials for sodium-ion batteries, thanks to their high theoretical capacity, excellent conductivity, and natural abundance. However, their potential is hampered by disappointing capacity retention and unsatisfactory lifespan, primarily attributed to volume expansion and unwanted structural collapse resulting from the insertion and extraction of relatively large Na+ ions during the charge and discharge processes. This feature article provides a brief overview of our endeavors to address the challenges associated with metal selenide-based anode materials, aiming to achieve high-performance electrode materials for sodium-ion batteries. Our strategy encompasses nanostructure design, materials composite engineering, heteroatoms doping, and topography and interface engineering. Additionally, future research directions are also outlined.

MOF-derived scaffolds as electrode materials: a mini-review.

Metal-organic frameworks (MOFs) have unique properties but suffer from low conductivity and poor stability, limiting their use in energy storage. Transforming MOFs into other materials, like porous carbon or metal oxides/chalcogenides has been explored to overcome these limitations. However, these approaches still face issues such as dead volume and poor attachment due to insulating binders, causing high resistance and detachment. To address this, MOFs and their derived scaffolds directly on conductive substrates without binders have emerged. These electrodes offer simplified preparation, enhanced electron transfer, and improved interface contact. This mini-review focuses on MOF-derived scaffold electrodes using transition metal oxides, sulfides, selenides, and tellurides, which show promise in energy storage applications. Valuable insights, identified opportunities, and future suggestions in the field of MOF-derived scaffold electrodes and their applications in energy storage applications have been discussed.

Unraveling the photocatalytic potential of transition metal sulfide and selenide monolayers for overall water splitting and photo-corrosion inhibition

A systematic study was carried out to identify transition metal sulfide and selenide (TMSS) monolayers, which resist both photo-degradation and photo-corrosion in a single electrolyte towards overall water splitting (OWS).

Rational design and application of electrocatalysts based on transition metal selenides for water splitting

This review has systematically summarized the recent progress (basic principles, synthetic methods and strategies for enhancing catalytic activity) in TMSe-based electrocatalysts for HER, OER, and overall water splitting.

Three-dimensional bimodal pore-rich G/MXene sponge amalgamated with vanadium diselenide nanosheets as a high-performance electrode for electrochemical water-oxidation/reduction reactions.

Exploring new strategies to design non-precious and efficient electrocatalysts can provide a solution for sluggish electrocatalytic kinetics and sustainable hydrogen energy. Transition metal selenides are potential contenders for bifunctional electrocatalysis owing to their unique layered structure, low band gap, and high intrinsic activities. However, insufficient access to active sites, lethargic water dissociation, and structural degradation of active materials during electrochemical reactions limit their activities, especially in alkaline media. In this article, we report a useful strategy to assemble vanadium diselenide (VSe2) into a 3D MXene/rGO-based sponge-like architecture (VSe2@G/MXe) using hydrothermal and freeze-drying approaches. The 3D hierarchical meso/macro-pore rich sponge-like morphology not only prevents aggregation of VSe2 nanosheets but also offers a kinetics-favorable framework and high robustness to the electrocatalyst. Synergistic coupling of VSe2 and a MXene/rGO matrix yields a heterostructure with a large specific surface area, high conductivity, and multi-dimensional anisotropic pore channels for uninterrupted mass transport and gas diffusion. Consequently, VSe2@G/MXe presented superior electrochemical activity for both the HER and OER compared to its counterparts (VSe2 and VSe2@G), in alkaline media. The overpotentials required to reach a cathodic and anodic current density of 10 mA cm-2 were 153 mV (Tafel slope = 84 mV dec-1) and 241 mV (Tafel slope = 87 mV dec-1), respectively. The Rct values at the open circuit voltage were as low as 9.1 Ω and 1.41 Ω for the HER and OER activity, respectively. Importantly, VSe2@G/MXe withstands a steady current output for a long 24 h operating time. Hence, this work presents a rational design for 3D microstructures with optimum characteristics for efficient bifunctional alkaline water-splitting.