A nickel-functionalized copper metal–organic framework (Ni@Cu-MOF) was prepared by a facile volatilization method and a post-modification synthesis method at room temperature. The obtained Ni@Cu-MOF electrode delivered a high capacitance of 526 F/g at 1 A/g and had a long-term cycling stability (80% retention after 1200 cycles at 1 A/g) in a 6 M KOH aqueous solution. Furthermore, an asymmetric supercapacitor device was assembled from this Ni@Cu-MOF and activated carbon electrodes. The fabricated supercapacitor delivered a high capacitance of 48.7 F/g at 1 A/g and a high energy density of 17.3 Wh/kg at a power density of 798.5 kW/kg. This study indicates that the Ni@Cu-MOF has great potential for supercapacitor applications.

In this study, a lanthanide metal organic framework based on the ligand of terephthalic acid derived from waste polyethylene terephthalate (PET) bottles was designed and synthesized. The structure and morphology of the Tb-BDC was investigated by X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The Tb-BDC displays a high selectivity and sensitivity towards picric acid (TNP). The luminescence intensities exhibit a linear relation, with a concentration of TNP over the range of 1 × 10⁻⁵–1 × 10⁻⁴ M, with a limit of detection of 1 × 10⁻⁵ M. The sensing mechanism is also discussed. This is the first time that waste PET materials have been used as the starting precursor of terephthalic acid (BDC) for the fabrication of lanthanide MOF (metal organic framework), which is applied in sensing TNP.

Supercapacitors are widely used in many fields owing to their advantages, such as high power, good cycle performance, and fast charging speed. Among the many metal-oxide cathode materials reported for supercapacitors, NiMoO₄ is currently the most promising electrode material for high-specific-energy supercapacitors. We have employed a rational design approach to create a nanorod-like NiMoO₄ structure, which serves as a conductive scaffold for supercapacitors; the straightforward layout has led to outstanding results, with nanorod-shaped NiMoO₄ exhibiting a remarkable capacity of 424.8 F g^-1 at 1 A g^-1 and an impressive stability of 80.2% capacity preservation even after 3500 cycles, which surpasses those of the majority of previously reported NiMoO₄ materials. NiMoO₄//AC supercapacitors demonstrate a remarkable energy density of 46.31 W h kg^-1 and a power density of 0.75 kW kg^-1. This synthesis strategy provides a facile method for the fabrication of bimetallic oxide materials for high-performance supercapacitors.

Zn-ion batteries (ZIBs) are considered as a viable candidate for grid-scale energy storage with admirable capacity, high safety and low cost, but are severely hampered by the undesirable dendrite growth and parasitic reactions at the Zn anode side. The compositions of the electrolytes are critical to the performance enhancement of ZIBs. Conventional electrolytes are unable to meet the ever-growing requirements for fast-charging and wide-temperature operation of ZIBs. Despite the great achievements of (localized) highly concentrated electrolytes and low concentrated electrolytes with high donor number additives, they still face challenges of low ionic conductivity, high cost and sluggish de-solvation kinetics of Zn²⁺. Therefore, weakly solvating electrolytes (WSEs) are proposed to improve the aforementioned shortcomings, which have attracted intensive research enthusiasm in recent years. This review analyzes the functions, design criteria, and recent progress of WSEs and then a vision on future directions in this field is also presented. The insights will benefit the development of next-generation high-performance ZIBs.

Electrochemical water splitting is considered to be an important method for efficient hydrogen production to alleviate energy shortage and environmental pollution, but its development is currently limited by the slow oxygen evolution reaction (OER). To solve the sluggish reaction kinetics of OER, the focus is on the exploration of low-cost and efficient electrocatalysts, which is quite significant for the development of electrochemical water splitting. Herein, a NiFe layered double hydroxides (LDH) electrocatalyst (denoted as FNH) is achieved by a simple one-step hydrothermal method. The experimental results show that due to the synergistic interaction of introduced Fe species, the FNH possesses a special three-dimensional (3D) vertical nanosheet array structure, which results in efficient ion access. More importantly, the strong electronic interaction between Fe and Ni sites results in the optimized electronic structure of the Ni sites, which not only generates abundant Ni³⁺ sites as optimized active sites for OER, but also decrease the charge transfer resistance. Thus, the FNH catalyst exhibits an extraordinary overpotential of 386.8 mV to deliver 100 mA cm⁻², showing better activity than that of RuO₂, and satisfactory cycling stability after continuous operation for 28 h. Our work provides an easy-to-implement method to obtain high-efficiency OER electrocatalysts.

Emerging Zinc-ion hybrid supercapacitors (ZHSCs) are being vigorously pursued due to their sustainability, economic efficiency, high safety and excellent theoretical electrochemical properties. As a significant element in the advancement of ZHSCs, carbonaceous materials can be utilized for fabricating the cathode and electrolyte and protecting the Zinc anode. Despite advancements, challenges notably persist in the form of unsatisfactory rate performance, scarcity of active sites, and undesirable cycling stability within carbonaceous cathodes. Here, this mini-review thoroughly expounds on the recent progress of carbonaceous materials with different dimensions and the corresponding synthesis strategies. The complexity of the structure, morphology, and relevant properties of sophisticated carbonaceous materials employed in contemporary devices is discussed. Besides, we elaborate on the strategies for modifying these materials to achieve optimal characteristics. Finally, the assessment of the existing challenges and prospects for carbonaceous materials within ZHSCs is explored. We anticipate that the insights presented herein can pave the way for developing carbonaceous materials, heading toward future-generation energy storage devices.