Designing and constructing bimetallic organic framework nanostructures is an effective method to improve supercapacitor materials. In this paper, metal–organic frameworks (MOFs) are generated from different carboxylic acid ligands with nickel nitrate. The nickel 1,3,5-benzenetricarboxylate (Ni BTC) MOF electrode material exhibits excellent electrochemical performance. A series of bimetallic (Ni/Co) MOFs was synthesized by incorporating cobalt ions. Among them, Ni/Co-MOF-7:1 (with an optimal Ni/Co ratio of 7:1) demonstrates the best performance. Consequently, the optimized Ni/Co-MOF-7:1 exhibits a remarkable capacitive property of 755 F·g⁻¹ at 0.5 A·g⁻¹, and the material retains 81.6% of its initial capacity after 5000 cycles. Asymmetric supercapacitors assembled with Ni/Co-MOF-7:1 and activated carbon demonstrate an exceptional capacitive behavior of 235.7 F·g⁻¹ at 0.5 A·g⁻¹, and maintain 97.9% of their initial capacitance after the 5000 cycles at 5 A·g⁻¹.

Hydrogen, as a promising alternative to traditional fossil fuels, is crucial for addressing global energy shortage and environmental pollution. Remarkably, the hydrogen can be efficiently conversed and utilized by hydrogen electrocatalysis, consisting of hydrogen evolution reaction (HER) and hydrogen oxidation reaction (HOR). Nevertheless, even for the platinum group metal (PGM) catalysts, there exists the orders-of-magnitude kinetic gap between the HER/HOR in acidic and alkaline electrolytes, which severely restricts the advance of alkaline hydrogen energy technologies. Consequently, developing cost-effective and efficient alkaline HER/HOR electrocatalysts is of great significance. Remarkably, the introduction of p-block elements into PGM can induce the p-d orbital hybridization, electron structure regulation, intermediate behavior optimization, and so on, thus greatly enhancing the catalytic performance. Herein, the recent progress in alkaline HER/HOR on PGM-based electrocatalysts modified by p-block elements is summarized. Firstly, the detailed discussions on alkaline HER/HOR mechanism are conducted. Then, the design strategies for p-block non-metal and metal element modified PGM-based catalysts are summarized, respectively. Notably, the inherent correlation between the distinct catalytic component (p-block elements and PGM elements) and corresponding catalytic performance is emphatically explored. Finally, in view of the challenges in alkaline HER/HOR, the research directions in the future are proposed.

The practical application of metal–organic frameworks (MOFs) for energy storage is faced with great challenges, such as poor structural stability and limited active sites. Herein, we have co-designed a three-dimensional (3D) self-assembled hexagonal zeolitic imidazolate framework-L (ZIF-L) structure with a 3D conformation that greatly reduces the self-aggregation of two-dimensional (2D) layered materials. Due to the rational design of the specific morphology and atomically different coordination abilities of Ni²⁺ and Co²⁺ in the framework, the micro-nano electric field is constructed, and the structural stability and electrochemistry reaction activity of ZIF-L are obviously improved. Moreover, the consecutive hollow structure is also formed by regulating the Ni–Co ratio, which can significantly enhance the specific capacitance and cycling stability of the Ni-ZIF-L electrode through the formation of fast electrolyte ions transfer channels. Consequently, the Ni-ZIF-L-40 electrode exhibits a high specific capacity (568.9 F·g⁻¹ at 0.5 A·g⁻¹) and long cycle stability (89.5% retention after 5000 cycles at 5 A·g⁻¹). In addition, the Ni-ZIF-L-40//activated carbon (AC) asymmetric supercapacitor assembled using AC also shows an excellent cycling stability (91.1% retention after 4000 cycles at 5 A·g⁻¹). This study may open a new window for the practical application of intrinsic MOFs-based electrodes for energy storage and conversion.

Metal-organic frameworks (MOFs), which are porous crystal materials with a large surface area and high porosity, have been extensively studied. MOF derivatives with complex structures, including hollow, porous, core–shell, yolk–shell, multi-shell, and array structures, have garnered significant attention in the fields of energy, environment, and other areas due to their exceptional stability, electrical conductivity, and abundant metal active centers. The synthesis strategies, chemical structures, and various potential applications of MOF derivatives with different special structures in recent years are summarized in this review. The formation mechanisms of MOF derivatives with complex structures are described in detail, including Ostwald ripening, soft/hard template, ion exchange, selective etching, and thermally induced strategies. The practical applications of MOF derivatives in Li/Na/K ion batteries, Li-S batteries, air batteries, supercapacitors, hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, hydrogen oxidation reaction, and photocatalysis are discussed and highlighted in detail. The challenges and improvement strategies for complex architectures in the future are also anticipated.

Metal-organic framework (MOF) nanoparticles are successfully confined in the hollow mesoporous carbon spheres (HMCSs) through space-confined synthesis methods. The prepared ZIF-67@HMCSs nanocomposites act as effective sacrificial templates, which can afford Co²⁺ sources. After a facile solvothermal reaction and sequential cation etching, yolk–shell-structured layered double hydroxide@HMCSs (LDH@HMCSs) have been synthesized. The LDH@HMCSs nanocomposite possesses a three-dimensional (3D) hollow nanocage superstructure that effectively blocks the self-stacking of LDH nanosheets and promotes ion transport. Compared to CoFe-LDH@HMCSs, and Co-LDH@HMCSs, CoNi-LDH@HMCSs exhibit superior electrochemical performance and desalination performance due to the remarkable synergistic effect between the CoNi-LDH nanosheets and mesoporous N-doped carbon shells. The resultant CoNi-LDH@HMCSs-0.4-based capacitive deionization (CDI) device exhibits excellent salt adsorption capacity (SAC, 36.41 mg·g^–1) and good cycle stability. This work will confirm the significance of constructing superstructure and open new avenues for the practical application of CDI technology in water treatment.

Energy shortage hinders the rapid development of today’s society, and the emergence of electronic travel equipment alleviates this phenomenon to a certain extent. The batteries are the energy storage part of electric equipment. Metal-organic frameworks (MOFs) are a fresh sort of porous crystal materials with controllable structure, large specific surface area, and adjustable pore size. MOFs are good electrode materials, which are used to make a variety of friendly environment, long cycling life and superior energy density of new batteries. Furthermore, MOFs are also used in separators and electrolytes, which have a lot of application space in batteries. In this review, the up-to-date research advance of MOF materials in various kinds of batteries (lithium-ion batteries, lithium oxygen batteries, lithium sulfur batteries, zinc-ion batteries, potassium-ion batteries, etc.) is reviewed. Moreover, concisely introduced several conventional synthesis approaches of MOFs. Finally, Perspectives and directions on the future improvement of MOF in energy storage devices are proposed for meeting the requirement of practical applications.

Over the past few decades, metal–organic frameworks (MOFs) have been recognized as the most attractive energy-involved materials due to their unique features, including ultrahigh specific surface area, superior porous structure, and excellent customizability. Nevertheless, most pristine MOFs suffer from low electronic conductivity and chemical instability, which severely hindered their large-scale applications. Recently, MXene with abundant surface terminations and high metallic conductivity have been suggested as a valid substrate to improve the stability and conductivity of pristine MOFs. Importantly, MXene/MOF composites with enhanced conductivity, rich surface chemistry, and hierarchical structure facilitate the rapid electron/ion transfer and deliver better electrochemical properties than that of original materials through synergistic effects. Moreover, MXene/MOF composites can be designed into various derivatives with desired architecture and enhanced electrochemical performance. Therefore, the elaborate synthesis of MXene/MOF hybrids and their derivatives for energy-involved devices are of great interest. Herein, we provided a state-of-the-art review on the progress of MXene/MOF composites and their derivatives in terms of synthesis strategies and electrochemical applications. Furthermore, we put forward current challenges and feasible research directions for future development.