MXene and Their Composites for Oxygen Evolution Reactions

Open AccessRenewablesREVIEWS24 Jan 2023Two-dimensional materials for high-performance oxygen evolution reaction: fundamentals, recent progresses and improving strategies Xiong Yin, Yani Hua and Zhan Gao Xiong Yin Google Scholar More articles by this author , Yani Hua Google Scholar More articles by this author and Zhan Gao Google Scholar More articles by this author https://doi.org/10.31635/renewables.023.202200003 SectionsAboutPDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareFacebookTwitterLinked InEmail Oxygen evolution reaction (OER) has an essential role in many energy storage and conversion technologies, but its high overpotential and sluggish kinetics seriously astrict the energy efficiency. The development of efficient and inexpensive OER electrocatalysts is still a grand challenge. Two-dimensional (2D) materials with unique structure and electronic properties have wide application prospects toward OER. In this review, firstly introducing OER electrocatalytic mechanisms and some crucial parameters for evaluating OER electrocatalysts, the latest progresses in the design and construction of 2D materials for OER is systematically reviewed, including layered double hydroxides, 2D carbon materials, transition metal dichalcogenides, metal oxide and phosphide nanosheets, metal-organic frameworks, covalent-organic frameworks and MXenes. Emphatically, some effective design and optimization strategies to improve electrocatalytic activity and durability of 2D materials as OER electrocatalysts are comprehensively generalized. The advantages and shortcomings of these 2D materials are analyzed in detail and their practical applications are deeply understood, which is crucial for the rational design of high-performance OER electrocatalysts. Finally, the challenges and future development opportunities of 2D materials for enhanced OER are discussed. Our review is expected to provide certain guidance for the development of new low-cost 2D materials as advanced OER electrocatalysts. Download figure Download PowerPoint Previous articleNext article FiguresReferencesRelatedDetails Issue AssignmentNot Yet Assigned Copyright & Permissions© 2023 Chinese Chemical Society Downloaded 0 times PDF downloadLoading ...

Silica-derived nanostructured catalysts (SDNCs) are a class of materials synthesized using nanocasting and templating techniques, which involve the sacrificial removal of a silica template to generate highly porous nanostructured materials. The surface of these nanostructures is functionalized with a variety of electrocatalytically active metal and non-metal atoms. SDNCs have attracted considerable attention due to their unique physicochemical properties, tunable electronic configuration, and microstructure. These properties make them highly efficient catalysts and promising electrode materials for next generation electrocatalysis, energy conversion, and energy storage technologies. The continued development of SDNCs is likely to lead to new and improved electrocatalysts and electrode materials. This review article provides a comprehensive overview of the recent advances in the development of SDNCs for electrocatalysis and energy storage applications. It analyzes 337,061 research articles published in the Web of Science (WoS) database up to December 2022 using the keywords "silica", "electrocatalysts", "ORR", "OER", "HER", "HOR", "CO2RR", "batteries", and "supercapacitors". The review discusses the application of SDNCs for oxygen reduction reaction (ORR), oxygen evolution reaction (OER), hydrogen evolution reaction (HER), carbon dioxide reduction reaction (CO2RR), supercapacitors, lithium-ion batteries, and thermal energy storage applications. It concludes by discussing the advantages and limitations of SDNCs for energy applications.

The development of renewable energy conversion and storage has triggered the development of electrode materials for oxygen evolution reaction (OER) and supercapacitors. Here we report a highly active Cu doped NiFe nanosheets hydroxide electrode with rich oxygen vacancies (OVs) (denoted as H-NiFeCuO/NF) prepared by in situ anodic electrodeposition on the three-dimensional macroporous nickel foam (NF) substrate followed by heat treatment with H2. The as-prepared H-NiFeCuO/NF electrode showed the initial potential of 1.44 V (versus RHE) for OER and 980 F g−1 specific capacity as supercapacitor in 1 M KOH. Further investigation suggested that the tuning of composition and structure by doping copper ions and creating OVs helped accelerate the electrochemical reactions. This practice provides an efficient approach for the fabrication of heteromultimetallic hydroxide monolithic electrode with high performance in OER or supercapacitor application.

Increasing the global energy demand as well as the carbon dioxide (CO2) level in the atmosphere caused by burning fossil fuel as the main source of energy motivate the development of green energy technologies. However, the real activity improvement for these technologies is mainly impeded by intermittent nature of renewable energy technologies. One smart approach to overcome this issue is to store energy into the chemical bonds1–6 using inexpensive and efficient energy conversion and storage technologies. In these systems, energy can be converted or stored into chemical bonds as a form of fuels or electricity using renewable energy sources, e.g., solar and wind energy7–9. Despite recent progress, the development of these systems is advanced far more slowly due to the expensive and less efficient materials employed in these technologies. Here, I will present my aim to design, synthesis, and characterization of inexpensive earth-abundant transition metal dichalcogenide class of materials suitable for energy conversion and storage systems. I have tested the performance of this class of catalysts for the carbon dioxide (CO2) reduction reaction, oxygen reduction, oxygen evolution reactions. The results indicate (i) 100 times higher turn over frequency- per atom activity- far exceeding the performance of state-of-the-art catalysts for CO2 reduction reaction, and (ii) a highly efficient bi-functional catalyst for oxygen reduction and evolution reactions in the aprotic media compared to conventional noble metal catalysts used for the same application (e.g., Platinum and Gold). I also tested the performance of molybdenum disulfide nanoflakes (MoS2 NFs) -a versatile member of TMDCs- in lithium-air batteries known as a promising alternative to the conventional lithium-ion batteries. The results indicate that MoS2 NFs in the ionic liquid EMIM-BF4 electrolyte performs remarkably well in the actual air environment with a small discharge/charge potential gap as well as good stability and cyclability up to 550 cycles without any evidence of failure. I will discuss these and other results including the potential of our recent discovery to open a new route towards energy efficient, highly active and cost-effective energy storage and conversion systems to replace fossil fuels.

We present a controlled fabrication of selective ultrathin metal–organic framework (MOF) nanosheets as preassembling platforms, yolk–shell structured with a few-layered N-doped carbon (NC) shell-en...

2D metal–organic frameworks and their derivatives for the oxygen evolution reaction

In this chapter, recent research progress in engineered 2D material electrocatalysts for improved OER performance is summarized. Initially, we have outlined the sequential events that took place in an alkaline and an acidic medium in order to provide knowledge about the evolution of oxygen. The key points related to these mechanisms were also addressed. Next, various material designing strategies for improving OER performance, including defects, doping, alloying, strain, edge engineering, morphological tuning, and heterostructure generation used for enhancing OER performance are described. These approaches will contribute to increasing the availability of active sites and their exposure to catalytic reactions, which will help to improve the performance of 2D materials. Finally, we highlight a number of challenges and possibilities that may present design opportunities for 2D material electrocatalysts of the future.

Green hydrogen production from renewable energy can help overcome difficult energy challenges worldwide. It can help decarbonize hard-to-abate sectors such as steel, chemicals, and ammonia fertilizer. Polymer Electrolyte Membrane (PEM) water electrolyzer serves as a promising technology when coupled with the fluctuating renewable energies for hydrogen production, with the advantages of fast response, dynamic operation, and excellent overload capacity. However, the only technically feasible anode catalysts for PEM are built on scarce iridium and require more than 40 years of annual production for 1 TW-scale. The scarce metal iridium has become a bottleneck limiting the scale development of PEM water electrolysis technology. Therefore, identifying earth-abundant catalysts with high activity and acid tolerance is essential to realizing large-scale hydrogen production via water electrolysis. Various 3d transition metals have been investigated as potential OER catalysts. In 2019, we reported how manganese oxide shows exceptional stability among earth-abundant materials for oxygen evolution reaction (OER) in acid. At the time, non-precious metal catalysts had difficulty maintaining activity for more than a week at 10 mA cm-2. In comparison, manganese oxide (γ-MnO2) was able to electrolyze water for over 11 months at 10 mA cm-2. This was made possible by identifying a stable potential window for γ-MnO2 in which the OER can be catalyzed efficiently while simultaneously suppressing deactivation pathways. After that, a binary spinel oxide catalyst (Co2MnO4) was synthesized by mixing stable manganese with active cobalt using a thermal decomposition method. Cobalt oxides were shown to be active for the OER but unstable in acid. By incorporating Mn into the Co3O4 spinel lattice, the lifetime was extended by two orders of magnitude while maintaining the activity. The water electrolysis with Co2MnO4 in acid can be sustained over 1500 hours at 200 mA cm-2. The activation barrier of the obtained spinel Co2MnO4 is comparable to state-of-the-art iridium oxides, which are reported to have activation energies of 25-30 kJ mol-1 in acidic conditions. The catalyst dissolution was experimentally analyzed by spectroscopy methods. It is clarified that the tetrahedral Co is the preferable dissolution site and the dissolution rate is suppressed in Co2MnO4 compared to Co3O4, resulting in outstanding stability. The active working time of Co2MnO4 as a function of current density for the OER reaction and other earth-abundant electrocatalysts reported in the literature were summarized. The marked improvement of the activity and stability in acid makes cobalt manganese spinel materials an intriguing candidate for non-noble metal water electrolysis. Acknowledgments: This work was supported by the New Energy and Industrial Technology Development Organization (NEDO). Figure caption: Long-term stability of Co2MnO4 during the OER in acid. a, Time dependence of the electrochemical potential necessary to perform OER at 100, 200, 500 and 1,000 mA cm-2 geo in H2SO4 (pH 1) and H3PO4 (pH 1), respectively. The stabilities of Co3O4 and γ-MnO2 in H2SO4 (pH 1) are shown for comparison. All the experiments were performed at 25 °C using an FTO substrate except for curve IX, for which a Pt/Ti mesh was used. b, A comparison of the stability of Co2MnO4 with Co3O4 and other Earth-abundant OER catalysts reported in the literature12-28 (Please refer Nat Catal 5, 109–118 (2022)) (upwards and downwards triangles represent lifetime and operation time, respectively). The measurements were performed under acidic conditions. Data points with roman numerals (I to XI) correspond to curves I to XI in a. Diagonal lines indicate the total amount of charge transferred before deactivation. Only studies that report stability at pH < 3 were included in the literature survey. Figure 1

Hydrogen generation from electrochemical water‐splitting is an attractive technology for clean and efficient energy conversion and storage, but it requires efficient and robust non‐noble electrocatalysts for hydrogen and oxygen evolution reactions (HER and OER). Nonprecious transition metal–organic frameworks (MOFs) are one of the most promising precursors for developing advanced functional catalysts with high porosity and structural rigidity. Herein, a new transition metal‐based hollow multivoid nanocuboidal catalyst synthesized from a ternary Ni–Co–Fe (NCF)‐MOF precursor is rationally designed to produce dual‐functionality toward OER and HER. Differing ion exchanging rates of the ternary transition metals within the prussian blue analog MOF precursor are exploited to produce interconnected internal voids, heteroatom doping, and a favorably tuned electronic structure. This design strategy significantly increases active surface area and pathways for mass transport, resulting in excellent electroactivities toward OER and HER, which are competitive with recently reported single‐function nonprecious catalysts. Moreover, outstanding electrochemical durability is realized due to the unique rigid and interconnected porous structure which considerably retains initial rapid charge transfer and mass transport of active species. The MOF‐based material design strategy demonstrated here exemplifies a novel and versatile approach to developing non‐noble electrocatalysts with high activity and durability for advanced electrochemical water‐splitting systems.

The active phase and catalytic mechanisms of Ni-based layered double hydroxide (LDH) materials for oxygen evolution reaction (OER) have no common consensus and remain controversial. Moreover, engineering the site activity and the number of active sites of LDHs is an efficient approach to advance the OER activity, as the thickness and stacking structure of the LDHs layer limit the catalytic activity. This work presents an interesting in situ approach of tuning the site activity and number of active sites of NiMn-LDHs, which exhibit the superior OER performance (onset overpotential of 0.17 V and overpotential of 0.24 V at 10 mA cm-2). The fundamental mechanistic insights and active phases during the OER process are characterized by in operando techniques along with the computational density functional theory calculations, revealing that the Ni site constitutes the OER activity and the dynamically generated NiOOH moiety is the active phase. We also prove that Ni sites undergo a reversible oxidation state under the working conditions to create active NiOOH species which catalyze the water to generate oxygen. These findings suggest that the Ni(III) phase in NiMn-LDHs is the OER active site and Mn promotes the electronic properties of Ni sites. Utilizing in situ/in operando techniques and theoretical calculation, we find that the in situ intercalation of guest anions allows the expansion of the LDH layers and keeps the active NiOOH species under the oxidation state of +3 via electron coupling, which ultimately tunes the site populations and site activity toward the superior OER activity, respectively. This work thus targets to provide insight into strategies to design the next generation of highly active catalysts for water electrolysis and fuel cell technologies.

Oxygen evolution reaction (OER) represents a highly important electrochemical transformation in energy storage and conversion technologies. Considering the low rate of this four-electron half-reaction, there is a demand for efficient, stable, and noble-metal-free electrocatalysts to improve the kinetic and economical parameters. In this work, a new pillared-MOF@NiV-LDH nanocomposite based on a CoII metal-organic framework (pillared-MOF) and heterometallic Ni/V-layered double hydroxide (NiV-LDH) was assembled via a simple protocol, characterized, and explored as an electrocatalyst in OER. A remarkable electrocatalytic efficiency of pillared-MOF@NiV-LDH in 1 M KOH is evidenced by a low overpotential (238 mV at 10 mA cm-2 current density) and a small value of the Tafel slope (62 mV dec-1). These parameters are very close to those of the reference IrO2 electrocatalyst and are superior to the majority of the LDH- and MOF-based systems previously applied for OER. Excellent stability of pillared-MOF@NiV-LDH was confirmed by the chronopotentiometry tests for 70 h and linear-sweep voltammetry after 7000 cycles. Features such as rich electroactive sites, porous structure, high surface area, and synergic effect between pillared-MOF and NiV-LDH are likely responsible for the remarkable electrocatalytic efficiency of this electrocatalyst in OER. Despite prior reports on the application of NiV-LDH in OER, the present study describes the first example where this type of LDH is blended with MOF to generate a nanocomposite material. The interface between the two components of the composite can improve the electronic structure and, in turn, the electrocatalytic behavior. The introduction of this composite paves the way toward the synthesis of other multicomponent materials with potential applications in different energy fields.

Exploring efficient and inexpensive oxygen evolution reaction (OER) electrocatalysts is of great importance for various electrochemical energy storage and conversion technologies. Ni-based electrocatalysts have been actively pursued because of their promising activity and earth abundance. However, the OER efficiency for most of the developed Ni-based electrocatalysts has been intrinsically limited due to their low electrical conductivity and poor active site exposure yield. Herein, we report metallic Ni3N nanosheets as an efficient OER electrocatalyst for the first time. The first-principles calculations and electrical transport property measurements unravel that the Ni3N is intrinsically metallic, and the carrier concentration can be remarkably improved with dimensional confinement. The EXAFS spectra provide solid evidence that the Ni3N nanosheets have disordered structure resultant of dimensional reduction, which then could provide more active sites for OER. Benefiting from enhanced electrical conductivity with metallic behavior and atomically disordered structure, the Ni3N nanosheets realize intrinsically improved OER activity compared with bulk Ni3N and NiO nanosheets. Our finding suggests that metallic nitride nanosheets could serve as a new group of OER electrocatalysts with excellent property.

Co9S8-porous carbon spheres as bifunctional electrocatalysts with high activity and stability for oxygen reduction and evolution reactions

Preparing high‐efficiency, durable and low overpotential electrocatalytic materials for oxygen evolution reaction (OER) plays a key role in water electrolysis. At present, electrochemical water separation technology has become the most promising sustainable hydrogen production process. The inherent hysteresis kinetics of oxygen evolution reaction (OER) is the key bottleneck of water electrolysis, which greatly restricts the energy conversion efficiency and practical large‐scale application. Herein, a facile method is developed to synthesize a series of trimetallic (Mo/Ni/Fe) metal‐organic frameworks (MOFs)‐derived carbon nanoparticles (CNPs) with various Fe content, and a Fe‐dependent volcano‐type plot can be drawn out for MoNiFex‐CNPs. The optimized MoNiFe0.4‐CNPs demonstrate superior electrocatalytic performance with a low overpotential of only 227 mV@10 mA cm−2 and excellent durability of 100 h. Its excellent OER performance is attributed to the synergistic effect of Fe/Ni bimetallic regulated by Mo. This work improved the catalytic performance of MOFs in the OER and proposed a new strategy for the structural design of MOFs.

Developing efficient and sustainable electrocatalysts for the oxygen evolution reaction (OER) is crucial for advancing energy conversion and storage technologies. 3d transition-metal (oxy)hydroxides and spinel-type oxides have emerged as promising candidates due to their structural flexibility, oxygen redox activity, and abundance in earth's crust. However, their OER performance can be changed dynamically during the reaction due to surface reconstruction and transformation. Essentially, multiple elementary processes occur simultaneously, whereby the electrocatalyst surfaces undergo substantial changes during OER. A better understanding of these elementary processes and how they affect the electrocatalytic performance is essential for the OER electrocatalyst design. This review aims to critically assess these processes, including oxidation, surface amorphization, transformation, cation dissolution, redeposition, and facet and electrolyte effects on the OER performance. The review begins with an overview of the electrocatalysts' structure, redox couples, and common issues associated with electrochemical measurements of 3d transition-metal (oxy)hydroxides and spinels, followed by recent advancements in understanding the elementary processes involved in OER. The challenges and new perspectives are presented at last, potentially shedding light on advancing the rational design of next-generation OER electrocatalysts for sustainable energy conversion and storage applications.