Synthesis and properties of morphology controllable copper sulphide nanosheets for supercapacitor application

Enhanced Wire-Shaped Micro-Supercapacitor Treated with a Continuous Surface Atmospheric Pressure Plasma Jet Approach

Microscale, wire-shaped flexible supercapacitors are gaining significant attention due to the growing demand for wearable electronics and microrobotic technologies. Among various materials, copper sulfide stands out as an ideal candidate because of its superior electrochemical properties, which can be attributed to its nanostructured composition. This structure enhances the surface area, reduces ion transport distances, and improves charge-discharge kinetics. However, conventional electrode synthesis methods-such as annealing and hydrothermal processes-are limited by long production times and scalability issues, making them unsuitable for wire-shaped supercapacitor development. In this study, an innovative fabrication technique using an atmospheric pressure plasma jet (APPJ) for both surface treatment and material synthesis is proposed. By integrating the APPJ with a winding mechanism, roll-to-roll processing for continuous production is enabled, significantly enhancing the scalability of the manufacturing process. The fabricated wire-shaped microscale electrodes demonstrate high specific capacitance (153.39 mF cm-2), specific energy density (15.48 µWh cm-2), and excellent capacitance retention (91.32%) after 30 000 charge-discharge cycles. Furthermore, a wire-shaped solid-state flexible asymmetric supercapacitor is assembled using the fabricated electrodes in a coaxial configuration. The supercapacitor exhibits exceptional flexibility and energy storage performance, underscoring the practical applicability of the proposed method for advanced electronics.

Application of Copper-Sulfur Compound Electrode Materials in Supercapacitors

Supercapacitors (SCs) are a novel type of energy storage device that exhibit features such as a short charging time, a long service life, excellent temperature characteristics, energy saving, and environmental protection. The capacitance of SCs depends on the electrode materials. Currently, carbon-based materials, transition metal oxides/hydroxides, and conductive polymers are widely used as electrode materials. However, the low specific capacitance of carbon-based materials, high cost of transition metal oxides/hydroxides, and poor cycling performance of conductive polymers as electrodes limit their applications. Copper-sulfur compounds used as electrode materials exhibit excellent electrical conductivity, a wide voltage range, high specific capacitance, diverse structures, and abundant copper reserves, and have been widely studied in catalysis, sensors, supercapacitors, solar cells, and other fields. This review summarizes the application of copper-sulfur compounds in SCs, details the research directions and development strategies of copper-sulfur compounds in SCs, and analyses and summarizes the research hotspots and outlook, so as to provide a reference and guidance for the use of copper-sulfur compounds.

Emerging 2D Copper-Based Materials for Energy Storage and Conversion: A Review and Perspective

2D materials have shown great potential as electrode materials that determine the performance of a range of electrochemical energy technologies. Among these, 2D copper-based materials, such as Cu-O, Cu-S, Cu-Se, Cu-N, and Cu-P, have attracted tremendous research interest, because of the combination of remarkable properties, such as low cost, excellent chemical stability, facile fabrication, and significant electrochemical properties. Herein, the recent advances in the emerging 2D copper-based materials are summarized. A brief summary of the crystal structures and synthetic methods is started, and innovative strategies for improving electrochemical performances of 2D copper-based materials are described in detail through defect engineering, heterostructure construction, and surface functionalization. Furthermore, their state-of-the-art applications in electrochemical energy storage including supercapacitors (SCs), alkali (Li, Na, and K)-ion batteries, multivalent metal (Mg and Al)-ion batteries, and hybrid Mg/Li-ion batteries are described. In addition, the electrocatalysis applications of 2D copper-based materials in metal-air batteries, water-splitting, and CO₂ reduction reaction (CO₂ RR) are also discussed. This review also discusses the charge storage mechanisms of 2D copper-based materials by various advanced characterization techniques. The review with a perspective of the current challenges and research outlook of such 2D copper-based materials for high-performance energy storage and conversion applications is concluded.

Electrochemical Performance and Hydrogen Storage of Ni-Pd-P-B Glassy Alloy

The search for hydrogen storage materials is a challenging task. In this work, we tried to test metallic glass-based pseudocapacitive material for electrochemical hydrogen storage potential. An alloy ingot with an atomic composition of Ni₆₀Pd₂₀P₁₆B₄ was prepared via arc melting of extremely pure elements in an Ar environment. A ribbon sample with a width of 2 mm and a thickness of 20 mm was produced via melt spinning of the prepared ingot. Electrochemical dealloying of the ribbon sample was conducted in 1 M H₂SO₄ to prepare a nanoporous glassy alloy. The Brunauer-Emmett-Teller (BET) and Langmuir methods were implemented to obtain the total surface area of the nanoporous glassy alloy ribbon. The obtained values were 6.486 m²/g and 15.082 m²/g, respectively. The Dubinin-Astakhov (DA) method was used to calculate pore radius and pore volume; those values were 1.07 nm and 0.09 cm³/g, respectively. Cyclic voltammetry of the dealloyed samples revealed the pseudocapacitive nature of this alloy. Impedance of the dealloying sample was measured at different frequencies through use of electrochemical impedance spectroscopy (EIS). A Cole-Cole plot established a semicircle with a radius of ~6 Ω at higher frequency, indicating low interfacial charge-transfer resistance, and an almost vertical Warburg slope at lower frequency, indicating fast diffusion of ions to the electrode surface. Charge-discharge experiments were performed at different constant currents (75, 100, 125, 150, and 200 mA/g) under a cutoff potential of 2.25 V vs. Ag/AgCl electrode in a 1 M KOH solution. The calculated maximum storage capacity was 950 mAh/g. High-rate dischargeability (HRD) and capacity retention (Sn) for the dealloyed glassy alloy ribbon sample were evaluated. The calculated capacity retention rate at the 40th cycle was 97%, which reveals high stability.

Enhanced Supercapacitor Performance and Electromagnetic Interference Shielding Effectiveness of CuS Quantum Dots Grown on Reduced Graphene Oxide Sheets

This study is focused on the preparation of the CuS/RGO nanocomposite via the hydrothermal method using GO and Cu-DTO complex as precursors. X-ray diffraction, Fourier-transform infrared spectroscopy, and Raman and X-ray photoelectron spectroscopy study revealed the formation of the CuS/RGO nanocomposite with improved crystallinity, defective nanostructure, and the presence of the residual functional group in the RGO sheet. The morphological study displayed the transformation of CuS from nanowire to quantum dots with the incorporation of RGO. The galvanostatic charge/discharge curve showed that the CuS/RGO nanocomposite (12 wt % Cu-DTO complex) has tremendous and outperforming specific capacitance of 3058 F g-1 at 1 A g-1 current density with moderate cycling stability (∼60.3% after 1000 cycles at 10 A g-1). The as-prepared nanocomposite revealed excellent improvement in specific capacitance, cycling stability, Warburg impedance, and interfacial charge transfer resistance compared to neat CuS. The fabricated nanocomposites were also investigated for their bulk DC electrical conductivity and EMI shielding ability. It was observed that the CuS/RGO nanocomposite (9 wt % Cu-DTO) exhibited a total electromagnetic shielding efficiency of 64 dB at 2.3 GHz following absorption as a dominant shielding mechanism. Such a performance is ascribed to the presence of interconnected networks and synergistic effects.

CuS nanoparticles decorated MoS2 sheets as an efficient nanozyme for selective detection and photocatalytic degradation of hydroquinone in water

Cost effective and efficient CuS–MoS₂ nanocomposite with enhanced peroxidase enzyme mimetics and photocatalytic activity was synthesized by simple hydrothermal method and successfully utilized for sensing and detection of toxic hydroquinone molecules in aqueous medium.

Structure based optical properties and catalytic activities of hydrothermally prepared CuS nanostructures

The nano-sized copper sulfides (CuS) with different morphologies were prepared by hydrothermal method without any surfactant or template. The morphology and structure of CuS were characterized by powder x-ray diffraction (XRD), Fourier transform infrared spectroscopy, x-ray photoelectron spectra (XPS), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), Brunauer-Emmett-Teller (BET) and ultraviolet-visible (UV-vis) absorption spectroscopy. FESEM results show that four morphologies of CuS (flower-like nanospheres, cross-linked nanodisks, cross-linked nanoplates and nanosheets) were prepared simply by changing the hydrothermal solvent. According to the XPS, XRD and HRTEM results the synthesized nano-sized structures are highly crystallized pure hexagonal covellite CuS. UV-vis spectra results show intense absorption peaks in the visible region, confirming that the resultant CuS has potential application in the field of solar cells. The catalytic activities of resultant CuS on model pollutant methylene blue (MB) in the dark were also investigated in detail. The small and flat crystallites show rapid degradation rate on MB, which is attributed to the numerous active sites on their large specific surface area. The as-synthesized CuS nanosheets took the shortest time (only 15 min) to degrade MB completely compared with the other nanostructural CuS in this work as well as previously reported ones. Total organic carbon removal of the samples approved mineralization of the MB pollutant. Thus, CuS is an excellent catalyst for degrading organic pollutants, which does not require light energy for its catalytic activities.

Diversified copper sulfide (Cu2-xS) micro-/nanostructures: a comprehensive review on synthesis, modifications and applications

As a significant metal chalcogenide, copper sulfide (Cu_2-xS, 0 < x < 1), with a unique semiconducting and nontoxic nature, has received significant attention over the past few decades. Extensive investigations have been employed to the various Cu_2-xS micro-/nanostructures owing to their excellent optoelectronic behavior, potential thermoelectric properties, and promising biomedical applications. As a result, micro-/nanostructured Cu_2-xS with well-controlled morphologies, sizes, crystalline phases, and compositions have been rationally synthesized and applied in the fields of photocatalysis, energy conversion, in vitro biosensing, and in vivo imaging and therapy. However, a comprehensive review on diversified Cu_2-xS micro-/nanostructures is still lacking; therefore, there is an imperative need to thoroughly highlight the new advances made in function-directed Cu_2-xS-based nanocomposites. In this review, we have summarized the important progress made in the diversified Cu_2-xS micro-/nanostructures, including that in the synthetic strategies for the preparation of 0D, 1D, 2D, and 3D micro-/nanostructures (including polyhedral, hierarchical, hollow architectures, and superlattices) and in the development of modified Cu_2-xS-based composites for enhanced performance, as well as their various applications. Furthermore, the present issues and promising research directions are briefly discussed.

MnS nanocomposites based on doped graphene: simple synthesis by a wet chemical route and improved electrochemical properties as an electrode material for supercapacitors

Nanocomposites of MnS anchored on graphene, nitrogen-doped graphene and boron-doped graphene have been prepared by a simple wet chemical process.

Facile synthesis of novel CuCo2S4 nanospheres for coaxial fiber supercapacitors

A flexible coaxial supercapacitor was designed using CuCo₂S₄ nanospheres on Ti wire, which exhibit satisfactory performances with high capacitance, excellent cycle stability and high energy density.

Simple synthesis of cobalt sulfide nanorods for efficient electrocatalytic oxidation of vanillin in food samples

Well-defined CoS nanorods (NR) were synthesized using a simple hydrothermal method, and were tested as an electrode material for electro-oxidation of vanillin. The NR material was characterized with regard to morphology, crystallinity, and electro-activity by use of appropriate analytical techniques. The resulting CoS NR@Nafion modified glassy carbon electrode (GCE) exhibited efficient electro-oxidation of vanillin with a considerable linear range of current-vs-concentration (0.5-56μM vanillin) and a detection limit of 0.07μM. Also, food samples containing vanillin were studied to test suitability for commercial applications.