Binder-free 3D flower-like alkali doped- SnS2 electrodes for high-performance supercapacitors

Exploring the effect of oxygen plasma on SnS2-ZnFe2O4based supercapacitor electrodes

The present study focuses on the fabricate the SnS2-ZnFe2O4compound to be employed as electrode materials in pseudocapacitors and raise its capacitance via direct-current O2plasma (DCOP) treatment. To maximally increase the capacitance of the constructed electrodes, the best conditions concerning temperature, exposure time, and power, as features of DCOP, were initially determined. Using the three-electrode cyclic voltammetry measurements, the electrodes exhibited the highest specific capacitance (733 F g-1) when the exposure time, output power, and temperature were set to 25 min, 1700 W, and 25 °C, respectively. The energy and power densities of the fabricated symmetric supercapacitor were estimated to be 43.5 Wh kg-1, which is considered substantially high, and 750 W kg-1, respectively, at a highest operating voltage of 1.5 V. The functional groups of the created electrodes were also analyzed, and it was found that the reason for considerable increases in the capacitance was improvement of the functional groups comprising oxygen such as O-Sn-O, Sn-O-C, and Fe-O on the surface of the SnS2-ZnFe2O4electrodes.

Solvothermally Synthesized Nickel-Doped Marigold-Like SnS2 Microflowers for High-Performance Supercapacitor Electrode Materials

Two-dimensional transition-metal dichalcogenides (TMDs) have emerged as promising capacitive materials for supercapacitors owing to their layered structure, high specific capacity, and large surface area. Herein, Ni-doped SnS2 microflowers were successfully synthesized via a facile one-step solvothermal approach. The obtained Ni-doped SnS2 microflowers exhibited a high specific capacitances of 459.5 and 77.22 F g-1 at current densities of 2 and 10 A g-1, respectively, in NaClO4 electrolyte, which was found to be higher than that of SnS2-based electrodes in various electrolytes such as KOH, KCl, Na2SO4, NaOH, and NaNO3. Additionally, these microflowers demonstrate a good specific energy density of up to 51.69 Wh kg-1, at a power density of 3204 Wkg-1. Moreover, Ni-doped SnS2 microflowers exhibit a capacity retention of 78.4% even after 5000 cycles. Better electrochemical performance of the prepared electrode may be attributed to some important factors, including the utilization of a highly ionic conductive and less viscous NaClO4 electrolyte, incorporation of Ni as a dopant, and the marigold flower-like morphology of the Ni-doped SnS2. Thus, Ni-doped SnS2 is a promising electrode material in unconventional high-energy storage technologies.

Enhanced photocatalytic performance of SnS2 under visible light irradiation: strategies and future perspectives

Tin(II) sulfide (SnS2) has emerged as a promising candidate for visible light photocatalytic materials. As a member of the transition metal dichalcogenides (TMDs) family, SnS2 features a band gap of approximately 2.20 eV and a layered structure, rendering it suitable for visible light activation with a high specific surface area. However, the application of SnS2 as a visible light photocatalyst still requires improvement, particularly in addressing the high recombination of electrons and holes, as well as the poor selectivity inherent in its perfect crystal structure. Therefore, ongoing research focuses on strategies to enhance the photocatalytic performance of SnS2. In this comprehensive review, we analyze recent advances and promising strategies for improving the photocatalytic performance of SnS2. Various successful approaches have been reported, including controlling the reactive facets of SnS2, inducing defects in the crystal structure, manipulating morphologies, depositing noble metals, and forming heterostructures. We provide a detailed understanding of these phenomena and the preparation techniques involved, as well as future considerations for exploring new science in SnS2 photocatalysis and optimizing performance.

Electrodeposited Copper Tin Sulfide/Reduced Graphene Oxide Nanospikes for a High-Performance Supercapacitor Electrode

Copper tin sulfide, Cu4SnS4 (CTS), a ternary transition-metal chalcogenide with unique properties, including superior electrical conductivity, distinct crystal structure, and high theoretical capacity, is a potential candidate for supercapacitor (SC) electrode materials. However, there are few studies reporting the application of Cu4SnS4 or its composites as electrode materials for SCs. The reported performance of the Cu4SnS4 electrode is insufficient regarding cycle stability, rate capability, and specific capacity; probably resulting from poor electrical conductivity, restacking, and agglomeration of the active material during continued charge-discharge cycles. Such limitations can be overcome by incorporating graphene as a support material and employing a binder-free, facile, electrodeposition technique. This work reports the fabrication of a copper tin sulfide-reduced graphene oxide/nickel foam composite electrode (CTS-rGO/NF) through stepwise, facile electrodeposition of rGO and CTS on a NF substrate. Electrochemical evaluations confirmed the enhanced supercapacitive performance of the CTS-rGO/NF electrode compared to that of CTS/NF. A remarkably improved specific capacitance of 820.83 F g-1 was achieved for the CTS-rGO/NF composite electrode at a current density of 5 mA cm-2, which is higher than that of CTS/NF (516.67 F g-1). The CTS-rGO/NF composite electrode also exhibited a high-rate capability of 73.1% for galvanostatic charge-discharge (GCD) current densities, ranging from 5 to 12 mA cm-2, and improved cycling stability with over a 92% capacitance retention after 1000 continuous GCD cycles; demonstrating its excellent performance as an electrode material for energy storage applications, encompassing SCs. The enhanced performance of the CTS-rGO/NF electrode could be attributed to the synergetic effect of the enhanced conductivity and surface area introduced by the inclusion of rGO in the composite.

Enhanced Optical Response of Zinc-Doped Tin Disulfide Layered Crystals Grown with the Chemical Vapor Transport Method

Tin disulfide (SnS₂) is a promising semiconductor for use in nanoelectronics and optoelectronics. Doping plays an essential role in SnS₂ applications, because it can increase the functionality of SnS₂ by tuning its original properties. In this study, the effect of zinc (Zn) doping on the photoelectric characteristics of SnS₂ crystals was explored. The chemical vapor transport method was adopted to grow pristine and Zn-doped SnS₂ crystals. Scanning electron microscopy images indicated that the grown SnS₂ crystals were layered materials. The ratio of the normalized photocurrent of the Zn-doped specimen to that of the pristine specimen increased with an increasing illumination frequency, reaching approximately five at 10⁴ Hz. Time-resolved photocurrent measurements revealed that the Zn-doped specimen had shorter rise and fall times and a higher current amplitude than the pristine specimen. The photoresponsivity of the specimens increased with an increasing bias voltage or decreasing laser power. The Zn-doped SnS₂ crystals had 7.18 and 3.44 times higher photoresponsivity, respectively, than the pristine crystals at a bias voltage of 20 V and a laser power of 4 × 10⁻⁸ W. The experimental results of this study indicate that Zn doping markedly enhances the optical response of SnS₂ layered crystals.