Two-dimensional SnS2 Nanosheets Research Articles

Enhanced photocatalytic reduction of CO2 using a novel 2D/0D SnS2/CeO2 binary photocatalyst with Z-scheme heterojunction and oxygen vacancy

In this work, suitable band gap width, strong photo-response to visible light, and a high photogenerated carrier density offered by an important member of layered sulfides, SnS2, were kept in view for designing and producing a highly effective photocatalyst for CO2 reduction. Hence, SnS2/CeO2 heterojunction composite photocatalysts were triumphally fabricated by a facile in situ hydrothermal synthesis method, combining advantages of the built-in electric field and oxygen vacancies of two materials. Various characterization techniques were exploited to scrutinize the photocatalyst’s structure and confirm that the carrier transport efficiency and photocatalytic performance are enhanced by the synergistic impact of the heterojunction structure and presence of oxygen vacancies. Owing to the successful loading of zero-dimensional CeO2 nanoparticles onto two-dimensional SnS2 nanosheets, the 2D/0D structure improves the photo-response range of the composites and provides faster electron transfer rates. The composite material maintained the hydrophobic characteristic of single SnS2, while inhibiting the hydrophilic property of single CeO2. As a result, CO and CH4 yields of prepared binary Z-type heterojunction photocatalysts are 24.6 and 4.4 folds higher than those of single SnS2, respectively. This innovative study will contribute to exploration of SnS2-based photocatalytic materials and provide a new feasible direction for light energy-driven CO2 reduction.

Urothermal Preparation and Antimicrobial Properties of Two-Dimensional Sns2 Nanosheets

Urothermal Preparation and Antimicrobial Properties of Two-Dimensional Sns2 Nanosheets

Magnetic and optical properties of two-dimensional SnS2 nanosheets doped with Ho ions

Ferromagnetic two-dimensional (2D) layered chalcogenide semiconductors have been considered as a promising candidate for the next-generation spintronic devices and photodevices. A major challenge is to prepare the stable ferromagnetic chalcogenide semiconductors materials with high Curie temperature. Herein, we introduce a facile approach to synthesize the two-dimensional SnS2 nanosheets with varying Ho dopant concentrations of 0 at.%, 0.71 at.%, 1.10 at.%, 1.43 at.%, 1.59 at.%, then we investigate the optical and magnetic properties of the-synthesized samples. The variable optical band gap and enhanced luminescence provide the evidences for the tune of the optical characteristics by changeable Ho doping concentration. Magnetic measurement results show that the enhanced room temperature ferromagnetism of the Ho doped two-dimensional SnS2 nanosheets with a maximum ferromagnetic response of 0.072 emu/g. Further first-principle calculations results address that the ferromagnetism of Ho-doped SnS2 is mainly derived from Sn vacancies and Ho substitution. This work suggests that the two-dimensional SnS2 nanosheets doped with rare earth atoms have potential applications in spintronics and optoeletronics.

Two-Dimensional SnS2 Nanosheets on Prussian Blue Template for High Performance Sodium Ion Batteries

SnS2/PB anode material was synthesized via two steps. First, three-dimensional Prussian Blue (PB) nanostructures were derived from a simple hydrothermal synthesis. After etching with hydrochloric acid (HCl), the PB nanocubes were used as a template for the next step. Two-dimensional SnS2 nanosheets were grown on the PB nanocubes through a facile hydrothermal synthesis, giving rise SnS2/PB hybrid nanoarchitecture. The as prepared SnS2/PB is further employed as the anode of sodium ion batteries (SIBs). The SnS2/PB nanoarchitecture exhibits high capacity, long cycle life and exceptional rate capabilities as an anode of SIBs. In specific, it delivers a capacity of 725.7 mA h g-1 at 50 mA g-1. When cycled through 200 cycles, it achieved a stable cycling capacity of 400 mAh g-1 at 200mA g-1 This enhanced SIB performance further proves that SnS2 has the capabilities and potential as an anode material for SIBs. The stable Na+ storage properties of SnS2/PB was attributed to the synergistic effect among the conductive PB carbon, used as the template in this work. These results obtained potentially paves the way for the development of excellent electrochemical performance with stable performance of SIBs. Keywords: Prussian Blue, Carbon Nanocubes, Tin disulfide, Sodium ion batteries Figure 1

Tunable Schottky barrier width and enormously enhanced photoresponsivity in Sb doped SnS2 monolayer

Doping, which is the intentional introduction of impurities into a material, can improve the metal-semiconductor interface by reducing Schottky barrier width. Here, we present high-quality two-dimensional SnS2 nanosheets with well-controlled Sb doping concentration via direct vapor growth approach and following micromechanical cleavage process. X-ray photoelectron spectroscopy (XPS) measurement demonstrates that Sb contents of the doped samples are approximately 0.22%, 0.34% and 1.21%, respectively, and doping induces the upward shift of the Fermi level with respect to the pristine SnS2. Transmission electron microscopy (TEM) characterization exhibits that Sb-doped SnS2 nanosheets have a high-quality hexagonal symmetry structure and Sb element is uniformly distributed in the nanosheets. The phototransistors based on the Sb-doped SnS2 monolayers show n-type behavior with high mobility which is one order of magnitude higher than that of pristine SnS2 phototransistors. The photoresponsivity and external quantum efficiency (EQE) of Sb-SnS2 monolayers phototransistors are approximately three orders of magnitude higher than that of pristine SnS2 phototransistor. The results suggest that the method of reducing Shottky barrier width to achieve high mobility and photoresponsivity is effective, and Sb-doped SnS2 monolayer has significant potential in future nanoelectronic and optoelectronic applications.

Two-dimensional SnS2 nanosheets arrays as photoelectrode by low temperature CVD method for efficient photoelectrochemical water splitting

Two-dimensional (2D) metal dichalcogenides have attracted considerable attention in photoelectrochemical (PEC) water splitting because of their particular layer structure and strong interaction with light. Herein, in this article, we report a facile chemical vapor deposition (CVD) method, via low boiling point SnCl4·5H2O and S powders as precursors. Light trapping nanosheets arrays SnS2 (SnS2⊥FTO) have been deposited on conductive substrate. By optimizing the preparation conditions, included deposition temperature, flow rate of carrier gas and the distance between the Sn source and growth substrate. Moreover, the key factors to affect the growth of SnS2 in CVD process have been investigated in detail. In PEC measurements, the as-synthesized thin film of 450 °C, 50 sccm, 11 cm shows the highest photocurrent density of up to 3.68 mA cm−2 at 0.5 V vs. SCE under the sunlight and high IPCE of up to 33.11% at 365 nm. The values much higher than conventional photoelectrode by spin-coating (SnS2//FTO), which achieved efficient photoelectrochemical water splitting under the sunlight.

Non-planar vertical photodetectors based on free standing two-dimensional SnS2 nanosheets.

The development trend of modern electronics and optoelectronics is towards continuous high integration and miniaturization. Using vertical configurations with three-dimensional geometry, it is easy to establish a higher integration density than the traditional planar one, and thus, this technology shows great promise for designing the next-generation electronics/optoelectronic devices. Two-dimensional (2D) layered metal dichalcogenides (2D-LMDs) are important building blocks for electronic/optoelectronic devices, where they are usually grown in parallel to the substrates during chemical vapor deposition (CVD), and consequently they are solely exploited to fabricate lateral structure devices with planar geometry. In this research, for the first time the vertical growth of free standing 2D layered nanosheets of hexagonal tin disulfide (SnS2) on a flat substrate was realized using a modified CVD method. Furthermore, it was successfully demonstrated, at the first attempt, that a type of non-planar vertical photodetector could be fabricated using free standing SnS2 nanosheets and this detector showed promise for photodetection applications. This work prepares the way for the growth of monodisperse vertical 2D-LMD nanosheets on flat substrates, and expands their use from conventional lateral structure devices to non-planar vertical electronic/optoelectronic devices.

Carbon dots decorated vertical SnS2 nanosheets for efficient photocatalytic oxygen evolution

Metal sulfides are highly desirable materials for photocatalytic water splitting because of their appropriate energy bands. However, the poor stability under light illumination in water hinders their wide applications. Here, two-dimensional SnS2 nanosheets, along with carbon dots of the size around 10 nm, are uniformly grown on fluorine doped tin oxide glasses with a layer of nickel nanoparticles. Significantly, strong light absorption and enhanced photocurrent density are achieved after integration of SnS2 nanosheets with carbon dots. Notably, the rate of oxygen evolution reached up to 1.1 mmol g−1 h−1 under simulated sunlight irradiation featuring a good stability.

Thermoelectric materials by using two-dimensional materials with negative correlation between electrical and thermal conductivity.

In general, in thermoelectric materials the electrical conductivity σ and thermal conductivity κ are related and thus cannot be controlled independently. Previously, to maximize the thermoelectric figure of merit in state-of-the-art materials, differences in relative scaling between σ and κ as dimensions are reduced to approach the nanoscale were utilized. Here we present an approach to thermoelectric materials using tin disulfide, SnS2, nanosheets that demonstrated a negative correlation between σ and κ. In other words, as the thickness of SnS2 decreased, σ increased whereas κ decreased. This approach leads to a thermoelectric figure of merit increase to 0.13 at 300 K, a factor ∼1,000 times greater than previously reported bulk single-crystal SnS2. The Seebeck coefficient obtained for our two-dimensional SnS2 nanosheets was 34.7 mV K−1 for 16-nm-thick samples at 300 K.

Two-Dimensional Tin Disulfide Nanosheets for Enhanced Sodium Storage

Sodium-ion batteries (SIBs) are considered as complementary alternatives to lithium-ion batteries for grid energy storage due to the abundance of sodium. However, low capacity, poor rate capability, and cycling stability of existing anodes significantly hinder the practical applications of SIBs. Herein, ultrathin two-dimensional SnS2 nanosheets (3-4 nm in thickness) are synthesized via a facile refluxing process toward enhanced sodium storage. The SnS2 nanosheets exhibit a high apparent diffusion coefficient of Na(+) and fast sodiation/desodiation reaction kinetics. In half-cells, the nanosheets deliver a high reversible capacity of 733 mAh g(-1) at 0.1 A g(-1), which still remains up to 435 mAh g(-1) at 2 A g(-1). The cell has a high capacity retention of 647 mA h g(-1) during the 50th cycle at 0.1 A g(-1), which is by far the best for SnS2, suggesting that nanosheet morphology is beneficial to improve cycling stability in addition to rate capability. The SnS2 nanosheets also show encouraging performance in a full cell with a Na3V2(PO4)3 cathode. In addition, the sodium storage mechanism is investigated by ex situ XRD coupled with high-resolution TEM. The high specific capacity, good rate capability, and cycling durability suggest that SnS2 nanosheets have great potential working as anodes for high-performance SIBs.