SnS2 Microspheres Research Articles

Pt-modified nanosheet-assembled SnS2 hollow microspheres for low temperature NO2 sensors

The three-dimensional (3D) microstructures assembled by nanomaterials have attracted great attention due to their unique hierarchical structure and large surface area. In this study, the hierarchical nanosheets-assembled SnS2 hollow microspheres with an average diameter of 6.1 μm were synthesized via a facile hydrothermal method. Then Pt nanoparticles were deposited on the surface of SnS2 to form Pt/SnS2 nanocomposites using the in-situ reduction method. Compared with pristine SnS2-based sensors, the Pt/SnS2 sensors exhibited improved gas-sensing performances to NO2 gas, including higher sensitivity, shorter response time, and better selectivity. The superior sensing performance can be ascribed to the Schottky junction created between Pt and SnS2, along with the catalytic effect of Pt. Moreover, the adsorption energy of SnS2 and Pt-modified SnS2 for NO2 molecules was calculated using first principles based on density functional theory (DFT). The Pt modification can enhance the interaction of NO2 with the SnS2 surface, which is favorable for improving the gas-sensing properties. This work provides novel hierarchical SnS2 microspheres based gas sensors for NO2 detection.

Multi-walled carbon nanotube decorated SnS2 microsphere and its supercapacitive properties

The present study leads to the investigation of high performance energy storage electrode material employing the simple and adoptable hydrothermal technique. The typical synthesis and characterization of SnS2 microspheres are reported. Furthermore, the supercapacitive performance of SnS2 microspheres is performed and 58 mAh g−1 of specific capacity is observed at the current density of 1 A g−1. Further, the specific capacity of sole SnS2 microspheres is enhanced by adding the modest amount of MWCNTs and improved specific capacity of 110 mAh g−1 is observed from MWCNT/SnS2 electrode material. Furthermore, due to the high specific capacity of composite, aqueous asymmetric supercapacitor (ASC) is designed with MWCNT/SnS2 as positive (+ve) electrode and activated carbon (AC) as negative (−ve) electrode. The high energy density of 37.14 W h kg−1 is delivered with the power density of 725 W kg−1 by MWCNT/SnS2//AC. In addition, for the electronic application, two parallel connected yellow color light emitted diodes (LEDs) are also lit by series connected two MWCNT/SnS2//AC devices.

Integration of hierarchical tin Sulfide@Sulfur-Doped carbon porous composites with enhanced performance for triiodide reduction

Constructing composites with positively synergistic effect is deemed as an effective strategy to further improve photovoltaic performance of dye-sensitized solar cells (DSSCs). However, the controllable synthesis of composites with intimate interface is still a big challenge. In this work, the solvothermal synthesis using SnCl2 and SnSO4 as tin source allows to grow the SnS microspheres (cSnS) and irregular SnS (sSnS). Subsequently, the hierarchical tin sulfide@sulfur-doped carbon porous composites (SnS@SC) have been ingenious synthesized by using SnCl2 as tin source through a facile hydrothermal method followed by the pyrolysis of coated glucose containing sulfur species under the nitridation atmosphere. As expected, the as-designed SnS@SC exhibited outstanding catalytic activity for triiodide reduction reaction (IRR) accompanying with a photoelectric conversion efficiency (PCE) of 7.54%, which reaches as high as 98.7% to that of the Pt (7.64%), as well as higher than that of the cSnS (6.21%) and sSnS (5.20%) in parallel. Compared with cSnS and sSnS, the further enhanced performance of SnS@SC can be mainly attributed to the more exposed active sites, the effective permeation of electrolyte, the decreased resistance, intimate interface and synergistic effect between SnS and S-doped carbon. Our discovery provides an extensible pathway to develop the active-site-enriched composites with beneficial structures in the field of the energy conversion.

Light absorption, photocarrier dynamic properties of hierarchical SnS2 microspheres and their performances on photodegradation of high concentration Rhodamine B

Heterogeneous photocatalysis has attracted considerable attention for environmental remediations, artificial photosynthesis, and the performance mainly depends on the light absorption, photocarrier dynamics and surface reactions of photocatalysts. Herein, the photocarrier dynamics of hierarchical SnS2 microspheres were studied by surface photovoltage and transient photovoltage spectra, in which the chemical composition, crystallinity, primary building blocks and assembling structures are affected by the light absorption and photocarrier transfer characteristics of SnS2. Further studies revealed that the enhanced visible light absorption and photocatalytic activity of Red-Embroidery-Ball-like microspheres were derived from the synergistic effects of S self-doping, the exciton transitions of surface states and the light trapping effects of porous hierarchical structure.

Insights into the photocatalysis mechanism of the novel 2D/3D Z-Scheme g-C3N4/SnS2 heterojunction photocatalysts with excellent photocatalytic performances

A novel 2D/3D Z-scheme g-C3N4/SnS2 photocatalyst was successfully fabricated via self-assembly forming 3D flower-like SnS2 microspheres on the surface of the 2D g-C3N4 nanosheets. The photocatalytic performances of the samples were systematically explored through catalytic reduction of Cr6+ and oxidation of Bisphenol S (BPS) under the illumination of visible light, and the photocatalytic degradation pathway of BPS was also proposed based on the degradation products confirmed by GCMS. Among the as-prepared samples, 0.4-g-C3N4/SnS2 exhibited the most efficient photocatalytic performances, and the apparent quantum efficiency (QE) for the removal of Cr6+ could achieve 30.3 %, which is 2.8 times higher than that of the SnS2. The enhancing photocatalytic activities originated from the efficient interfacial charge migration and separation obtained in g-C3N4/SnS2, which was firstly verified via the photoluminescence spectra, time-resolved photoluminescence spectra and photoelectrochemical characterizations. Importantly, the DFT calculated shows that the band distribution of the g-C3N4/SnS2 sample is staggered near the forbidden, which can facilitate the efficient interfacial charge migration and separation as well as result in the improvement of the catalytic activity. Finally, we put forward a more reasonable Z-scheme charge transfer mechanism, it was verified by analysing the results of free radical scavenging tests, EPR experiments and theoretical calculations.

Novel Z-scheme Ag-C3N4/SnS2 plasmonic heterojunction photocatalyst for degradation of tetracycline and H2 production

A novel Z-scheme Ag-C3N4/SnS2 plasmonic heterojunction photocatalyst was developed for the first time by in situ forming 3D flower-like SnS2 microspheres on the 2D Ag-C3N4 nanosheet. The photocatalytic performances of the samples were systematically examined via the photocatalytic water splitting for H2 production and photocatalytic degradation of tetracycline (TC) under visible light irradiation. Among the as-prepared Ag-C3N4/SnS2 samples with various Ag content, 5Ag-C3N4/SnS2 (the mass ratio of Ag to g-C3N4 is 5 wt%) sample exhibited the most efficient photocatalytic performances. Theapparentreactionrateconstantof 5Ag-C3N4/SnS2 for the photocatalytic oxidation of TC was 0.0201 min−1, which was 7.2, 4.9 and 3.0 times higher than those of the bare SnS2 (0.0028 min−1), g-C3N4 (0.0041 min−1) and g-C3N4/SnS2 (0.0066 min−1), respectively. As for the H2 production, a maximum of 1104.5 μmol g−1.h−1 can be achieved for the 5Ag-C3N4/SnS2. The enhancing photocatalytic performance was attributed to the enhanced absorbance in the visible light region caused by localized surface plasmon resonance (LSPR) and the efficient interfacial charge migration and separation in Ag-C3N4/SnS2 samples. In addition, the photocatalytic degradation pathway of TC was proposed based on nine degradation products confirmed by GC–MS. Finally, there were a series of characterization, such as time-resolved fluorescence emission decay spectra, photoelectrochemical characterizations, and stimulation methods (DFT, CASTEP, and FDTD), to verify the Z-scheme plasmonic heterojunction photocatalysis mechanism.

Hydrothermal-synthesis flower-like SnS microspheres gas sensors bonded physically by PVDF for detecting ethanol

Considering a fact that flower-like tin sulfide microspheres (for short SnS) sample is easy to fall off when it is used to fabricate sensing test components, PVDF (vinylidene fluoride) was used to glue the sample powder and the gas sensors instead of DI water (deionized water). The SnS were successfully synthesised through a facile hydrothermal method at 180 °C for 24 h. The properties of samples were characterised by utilizing BET, SEM, TEM, etc. The research results showed that the BET surface area and diameter of the samples were 43.87 m2/g and 1.8–4.2 μm, the response to 100 ppm ethanol was 92.96% with PVDF bonded samples at 240 °C, and the response time and recovery time were 1.8 and 90 s, respectively.

Rational Design of Hierarchical SnS2 Microspheres with S Vacancy for Enhanced Sodium Storage Performance

SnS2-based materials have been intensively explored as an anode for sodium-ion batteries. In the present study, hierarchical SnS2 microspheres with S vacancy have been successfully synthesized via ...

SnS/N-Doped carbon composites with enhanced Li+ storage and lifetime by controlled hierarchical submicron- and nano-structuring

Hollow and dense hierarchical SnS microspheres coated with a nitrogen doped carbon layer were synthesised, tested and compared as anodes in lithium ion battery half cells.

Facile synthesis of macroporus SnS microspheres as a potential anode material for enhanced sodium ion batteries

Macroporous SnS microspheres with open pores were prepared using a spray pyrolysis process followed by a simple sulfidation process. The macroporous SnO2 microspheres prepared from the precursor solution including tin ions and polystyrene beads transformed into the macroporous and phase-pure SnS microspheres by sulfidation at an optimized temperature of 350°C. The sulfidation process of the SnO2 microspheres without open pores obtained by spray pyrolysis formed SnS–SnO2 and SnS–Sn composite microspheres with filled structures at sulfidation times of 9 and 24h, respectively. The discharge capacities of the macroporous SnS microspheres with open pores and dense SnS–SnO2 and SnS–Sn microspheres for the 50th cycle at a current density of 0.5Ag−1 were 364, 231, and 264mAhg−1, respectively. The macroporous SnS microspheres with open pores showed higher capacities and superior rate capability for sodium ion storage compared to dense SnS–SnO2 and SnS–Sn microspheres.

Construction of Ni-doped SnO2-SnS2 heterojunctions with synergistic effect for enhanced photodegradation activity.

Construction of heterostructures with proper band alignment and effective transport and separation of photogenerated charges is highly expected for photocatalysis. In this work, Ni-doped SnO2-SnS2 heterostructures (NiSnSO) are simply prepared by thermal oxidation of Ni-doped hierarchical SnS2 microspheres in the air. When applied for the photodegradation of organic contaminants, these NiSnSO exhibit excellent catalytic performance and stability due to the following advantages: (1) Ni doping leads to the enhancement of light harvesting of SnS2 in the visible light regions; (2) the formed heterojunctions promote the transport and separation of photogenerated electrons from SnS2 to SnO2; (3) Ni-SnO2 quantum dots facilitate the enrichment of reactants, provide more reactive centers and accelerate product diffusion in the reactive centers; (4) the SnS2 hierarchical microspheres constituted by nanoplates provide abundant active sites, high structural void porosity and accessible inner surface to faciliate the catalytic reactions. As a result, the optimized NiSnSO can photodegrade 92.7% methyl orange within 80 min under the irradiation of simulated sunlight, greatly higher than those of pure SnS2 (29.8%) and Ni-doped SnS2 (52.1%). These results reveal that the combination of heteroatom doping and heterostructure fabrication is a very promising strategy to deliver nanomaterials for effectively photocatalytic applications.

Three-dimensional elastic ultrathin reduced graphene oxide coating SnS2 hierarchical microsphere as lithium ion batteries anode materials

Three-dimensional elastic ultrathin reduced graphene oxide coating SnS2 hierarchical microsphere (3D SnS2@RGO) have been successfully prepared by a convenient hydrothermal method. The morphology and structure of the 3D SnS2@RGO are characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Raman spectra. It is found that numerous of nanoflakes-assembly SnS2 microspheres are wrapped by ultrathin reduced graphene oxide nanosheets, which form a three-dimensional net-like structure. The electrochemical performance of 3D SnS2@RGO electrode was evaluated by cyclic voltammetry, galvanostatic charge-discharge tests and electrochemical impedance spectroscopy measurement. When evaluated as lithium ion batteries anode material, 3D SnS2@RGO electrode manifest better cycling performance (reserving 942 mAh g−1 after 100 cycles) and higher rate capability (689 mAh g−1 at the rate of 1000 mA g−1) than that of pure SnS2 (retaining 216 mAh g−1 after 100 cycles) (only 10.8 mAh g−1 at the current density of 1000 mA g−1). The excellent electrochemical performance can be attributed to the improvement of lithium ion diffusion and ionic conductivity which is caused by graphene-coating.

Non-stoichiometric SnS microspheres with highly enhanced photoreduction efficiency for Cr(vi) ions

Sn2+ self-doped SnS microparticles were synthesized via a simple template-free hydrothermal route. The ability to tune the band structure while minimizing defect generation makes self-doped SnS an efficient photocatalyst for treating waste water.

Reduced graphene oxide anchored tin sulfide hierarchical microspheres with superior Li-ion storage performance

Tin-based composites are promising high-capacity anode materials for Li-ion batteries, but they usually exhibit poor cycling stability because of their large volume expansion during the Li uptake and release process. We reported a facile solvothermal method to produce nanosheet-assembled SnS microspheres and a rational strategy to improve the electrochemical performance of SnS microspheres by anchoring on reduced graphene oxide (RGO) networks. The as-prepared SnS/RGO nanocomposites were characterized by XRD, SEM, TEM, TGA, and Raman spectra. The electrochemical results show that the SnS/RGO electrode exhibited high reversible capacity and good cycling stability (delivered a capacity of 760 mAh g−1 after 100 cycles at a current density of 100 mA g−1). The superior electrochemical performance can be attributed to the large available surface area, high conductivity, and fast transportation of electrons and Li-ions; these are benefited from the unique hybrid structure and the synergistic effect between SnS and RGO.

Graphene assistance enhanced dye-sensitized solar cell performance of tin sulfide microspheres

In this work, the nanosheet-assembled SnS2 microspheres were synthesized through a solvothermal method, and the catalytic activities of the microspheres were investigated by J-V and power conversion efficiency tests as counter electrodes in dye-sensitized solar cells. The cell showed an energy conversion efficiency up to 6.4%. To further improve the power conversion efficiency of the counter electrode of the microspheres, different amounts of reduced graphene were added into the microspheres by simply physical mixing. With the addition of 6 wt% reduced graphene, the short-circuit current density, open-circuit voltage and fill factor were 15.18mAcm−2, 775mV, and 63.4%, respectively. More important, the conversion efficiency reached 7.46%, which is approximately 17% higher than that of the cell with pure SnS2 microspheres as counter electrode. Compared to conventional materials used in dye-sensitized solar cells, SnS2 microspheres have the advantages of facile synthesis, low-cost and high efficiency with graphene assistance.

Uniform hierarchical SnS microspheres: Solvothermal synthesis and lithium ion storage performance

Hierarchical SnS microspheres have been successfully synthesized by a mild solvothermal process using poly(vinylpyrrolidone) as surfactant in this work. The morphology and composition of the microspheres were investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The influence of reaction parameters, such as sulfur sources, reaction temperature and the concentration of PVP, on the final morphology of the products are investigated. On the basis of time-dependent experiments, the growth mechanism has also been proposed. The specific surface area of the 3D hierarchitectured SnS microspheres were investigated by using nitrogen adsorption and desorption isotherms. Lithium ion storage performances of the synthesized materials as anodes for Lithium-ion battery were investigated in detail and it exhibits excellent electrochemical properties.

Self-assembly of SnS2 submicron-sized flakes to form microspheres under template-free hydrothermal conditions

SnS2 microspheres composed of submicron-sized flakes were successfully prepared via a simple surfactant-free hydrothermal reaction route at 240 °C for 12 h, using SnCl4 and Na2S as reactants. The powders were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The X-ray diffraction pattern confirmed that the SnS2 microspheres had a single-phase hexagonal structure. The SEM micrographs indicated that these microspheres with the size of ∼30 μm in diameter were mainly constructed by self-assembly of submicron-sized SnS2 flakes. The effect of reaction temperature and the amount of mineralizer (urea) on the formation of SnS2 microspheres under hydrothermal conditions were investigated and a possible formation mechanism was preliminarily presented.

Synthesis of flower-like SnS 2 nanostructured microspheres using PEG 200 as solvent

The flower-like tin disulphide (SnS2) microspheres have been synthesised by a facile solution-based route using polyethylene glycol 200 as the solvent and template. The products are characterised by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. Experimental results show that the flower-like SnS2 microspheres with diameters around 2–5 µm are made of many interleaving petal-like nanostructures. These nanopetals are 1–3 µm in side length and less than 60 nm in thickness. The influences of solvent and sulphur source on the morphology of SnS2 nanostructures have also been investigated. The possible growth mechanism is discussed. Furthermore, the room-temperature Raman spectrum of the flower-like SnS2 microspheres is also studied.