SnSe Nanosheets Research Articles

SnSe Nanosheet Array on Carbon Cloth as a High-Capacity Anode for Sodium-Ion Batteries.

Binder-free electrodes offer a great opportunity for developing high-performance sodium-ion batteries (SIBs) aiming at the application in energy storage devices. Tin selenide (SnSe) is considered to be a promising anode material for SIBs owing to its high theoretical capacity (780 mA h g-1). In this work, a SnSe nanosheet array (SnSe NS) on a carbon cloth is prepared using a vacuum thermal evaporation method. The as-prepared SnSe NS electrode does not have metal current collectors, binders, or any conductive additives. In comparison with the electrode of SnSe blocky particles (SnSe BP), the SnSe NS electrode delivers a higher initial charge capacity of 713 mA h g-1 at a current density of 0.1C and maintains a higher charge capacity of 410 mA h g-1 after 50 cycles. Furthermore, the electrochemical behaviors of the SnSe NS electrode are determined via pseudocapacitance and electrochemical impedance spectroscopy measurements, indicating a faster kinetic process of the SnSe NS electrode compared to that of the SnSe BP. Operando X-ray diffraction measurements prove that the SnSe NS exhibits better phase reversibility than the SnSe BP. After the cycles, the SnSe NS electrode still maintains its particular structure. This work provides a feasible method to prepare SnSe nanostructures with high capacity and improved sodium ion diffusion ability.

Ultra-sensitive terahertz introduced harmonic emission towards terahertz detection

The sixth-generation (6G) technology has garnered significant interest from researchers due to its improved spectral and energy efficiency. However, a major challenge lies in the strong attenuation of terahertz waves in the air, necessitating the development of ultra-sensitive detectors. In recent years, there has been gradual progress in the development of harmonic signal detection methods, offering a new solution for terahertz wave detection with a low detection threshold and high sensitivity. In our study, we proposed a highly sensitive detection approach involving a 1040 nm femtosecond laser and broadband terahertz waves incident on SnSe2 nanosheets with a few layers, obtained through mechanical exfoliation. Utilizing confocal microscopy, the distinct harmonic wave can be observed, with the intensity of the harmonic signal varying based on the polarization angle difference between the laser and terahertz waves. Our estimation suggests that this detection sensitivity could be around ten times higher than that of existing detectors. This approach, which involves THz-induced harmonic generation without the need for high voltage or intense THz/laser exposure, holds immense potential for weak signal detection applications and carries significant importance for the advancement of 6G technology.

In situ uniformly vertical growth of SnSe2 nanosheet arrays on carbon cloth as a self-supporting anode toward effective sodium-ion storage

Layered tin diselenide with high theoretical capacity and desirable redox voltage has emerged as a promising anode material for sodium-ion storage. However, achieving a highlight tin diselenide-based electrode that simultaneously exhibits prominent rate capability and ultralong cycling durability is the major challenge. Herein, highly efficient and durable SnSe2@CC nanosheet arrays were easily engineered based on the in situ growth of a SnO/SnO2 precursor on carbon cloth using a hydrothermal process followed by controlled selenation as an anode material for sodium-ion batteries. Benefiting from the uniformly vertical ultrathin nanosheet array morphology and the robust structural integrity of the self-supporting electrode, nanosheet aggregation and volume expansion were effectively alleviated, leading to fast reaction kinetics and satisfactory cycling ability. Thus, the resultant SnSe2@CC nanosheet arrays deliver an excellent reversible capacity of 604.7 mAh g−1 after 100 cycles at 0.1 A g−1, a rapid rate property with a specific capacity of 390.2 mAh g−1 at 5.0 A g−1 and ultral cycle lifespan with a reversible capacity of 350.4 mAh g−1 exceeding 1000 cycles. This research presents a novel method for the design and fabrication of advanced electrodes for sodium-ion storage.

The features of the solvothermal synthesis of SnSe nanosheets and nanoflowers for supercapacitor applications

In this article, orthorhombic SnSe nanoparticles (NPs) are prepared through hydrothermal method by using Olyelamine and Ethylene glycol solvent named as AN-(OA) and AN-(EG). The SEM and TEM images of the AN-(OA) and AN-(EG) NPs show sheet and flower-like shapes, respectively. The cyclic voltammograms (CV) and Galvanostatic charge/discharge (GCD) studies of AN-(OA) and AN-(EG) electrodes are investigated in 0.5 M of KOH electrolyte. The specific capacitance values calculated through CV curves are 443, 240, 172, 138, 118, 130 and 50 (F/g) of AN-(EG) electrode and 224, 116, 80, 62, 52, 31 and 20 (F/g) of AN-(OA) electrode at the scan rate of 10, 20, 30, 40, 50, 60 and 70 (mV/s), respectively. Further, the specific capacitance values calculated through GCD curves are 83, 66, 58 and 55 (F/g) of AN-(EG) electrode and 52, 33, 29 and 27 (F/g) of AN-(OA) electrode at the current density of 1, 2, 3 and 5 (A/g), respectively. The morphology plays a critical role in capacitive performance of NPs.

Facile Phase-Selectable Chemical Synthesis of Tin Selenide Nanosheets toward Nanostructured Materials for Energy-Related Applications

Here, we present a facile, phase-selectable, size-controllable chemical method for the synthesis of Sn-Se nanosheets (NSs). The resultant NSs were characterized using XRD, SEM, TEM, STEM, and EDS. Phase control was achieved by changing the input molar ratio of Sn:Se. At ratios of 1:1 and 1:2, pure-phase, rectangular SnSe NSs; at ratios of 1:6 and 1:10, pure-phase, hexagonal SnSe2 NSs; and at a ratio of 1:4, a mix of the two NSs were produced. The produced NSs were large (a few hundred nm in diameter) and thin (10–20 nm), although there was no significant increase in the optical band gap calculated from UV–vis–NIR spectroscopy, indicating an absence of quantum confinement effects. Size control of both phases was achieved by changing the amount of the ligand, trioctylphosphine oxide (TOPO). Increasing the amount of TOPO decreased the size of the SnSe NSs and increased the size of the SnSe2 NSs. Finally, the formation mechanism was investigated and it was found that the formation of metal-ion complexes, namely, Sn-TOPO and Se-oleylamine, played an important role in the phase selectivity and size distribution of the NSs by changing the effective ratio of Sn:Se and slowing the nucleation of the NSs.

An inorganic-organic hybrid indium tin selenide featuring a two-dimensional layered structure for high efficient photocatalytic Cr(VI) reduction

Photocatalytic reduction technique has been demonstrated as a promising method to treat Cr(VI)-containing wastewater. However, exploring effective photocatalysts with high activity to satisfy the demand from practical application is a challenge. Inorganic-organic hybrid metal chalcogenides should have great potentials as photocatalysts for Cr(VI) reduction due to their rich structural characteristics. Herein, an inorganic-organic hybrid indium tin selenide (Bmmim)8In8Sn8Se30(Se4)2 (BITS), featuring a two-dimensional layered structure, was synthesized through an ionothermal method. Owing to the unique layered structure, BITS can exhibit an outstanding photocatalytic performance for reducing Cr(VI) under visible light irradiation, where its Cr(VI) reduction rate was 26.3, 11.8, and 7.8 times higher than that of P25, In2Se3 nanoparticles, and SnSe2 nanosheets, respectively. Meanwhile, BITS showed a strong anti-interference ability to a variety of anions and cations, and accordingly, maintained its excellent photocatalytic performance in three water bodies, including tap water, lake water, and river water. In addition, BITS can also display a high efficiency for Cr(VI) reduction under sunlight irradiation. Photocatalytic mechanism investigation proved the key role of electrons to the Cr(VI) reduction. Our research results prove the great potential of inorganic-organic hybrid metal chalcogenides as photocatalysts for treating Cr(VI) in wastewater.

SnSe nanosheet hybridized with reduced graphene oxide for enhanced hydrogen revolution reaction

SnSe nanosheet hybridized with reduced graphene oxide for enhanced hydrogen revolution reaction

Electrostatic self-assembled SnSe@Ti3C2 with 3D network structure towards ultra-stable and high rate capability sodium ion storage

SnSe is an emerging anode for sodium ion storage due to its abundant resource, safety, reliability, narrow bandgap (0.9 eV) and outstanding theoretical capacity (780 mAh g−1). Nevertheless, the dissolution of discharge products (Na2Se) and the structure collapse during Na+ insertion/extraction result in a dramatic decline of capacity. Herein, SnSe nanosheets anchored on Ti3C2 (SnSe@Ti3C2) with a three-dimensional (3D) network structure is prepared by electrostatic self-assembly and annealing strategy. Ti3C2 with abundant functional groups and open pores facilitates the full reaction of the electrode and electrolyte. In addition, the 3D network structure of Ti3C2 substantially reduces the structural collapse and aggregation of SnSe as well as improves charge transfer kinetics of the composites. The synergistic effect between Ti3C2 with 3D skeleton and SnSe leads to ultra-long cycling stability (240.1 mAh g−1 at 0.1 A g−1 after 1350 cycles) and superior rate capability (128.6 mAh g−1 at 5.0 A g−1). SnSe@Ti3C2//AC sodium ion capacitor (SIC) possesses a capacity retention of 73.8% after 10000 cycles at 1.0 A g−1. The proposed design provides a broad prospect for transition metal dichalcogenide (TMD) based composites as superior anodes for sodium ion storage.

SnSe Nanosheets Mimic Lactate Dehydrogenase to Reverse Tumor Acid Microenvironment Metabolism for Enhancement of Tumor Therapy.

The acidic tumor microenvironment (TME) is unfriendly to the activity and function of immune cells in the TME. Here, we report inorganic nanozymes (i.e., SnSe NSs) that mimic the catalytic activity of lactate dehydrogenase to degrade lactate to pyruvate, contributing to the metabolic treatment of tumors. As found in this study, SnSe NSs successfully decreased lactate levels in cells and tumors, as well as reduced tumor acidity. This is associated with activation of the immune response of T cells, thus alleviating the immunosuppressive environment of the TME. More importantly, the nanozyme successfully inhibited tumor growth in mutilate mouse tumor models. Thus, SnSe NSs show a promising result in lactate depletion and tumor suppression, which exemplifies its potential strategy in targeting lactate for metabolic therapy.

Layered metal chalcogenide of SnSe nanosheets integrated with 2D-hexagonal boron nitride for accurate and low-level detection of nitrofurazone

Rising global demands for monitoring the health care and environmental system have increased the usage of antibodies as they are forced to deal with food products and environmental samples. Nitrofurazone (NF) is an important antibiotic that is widely used in clinical treatments, but its uncontrolled utilization and disposal wastage cause serious global issues into the ecosystem. Thus, a sensitive electrochemical method is developed for the real-time and low-level detection of NF. Layered metal chalcogenides of tin selenide (SnSe) integrated with hexagonal boron nitride (h-BN) are prepared as an electrode material for the detection of NF to take advantage of the unique structural and physiochemical properties of SnSe and h-BN. The physicochemical characteristics of SnSe/h-BN composite are determined with various spectral and analytical methods. The fabricated SnSe/h-BN electrode possesses excellent electrochemical activity for the detection of NF, with dual linear ranges of 0.001–12.12 µM and 15.2–342.2 µM, a low limit of detection of 0.34 nM, and a high sensitivity of 1.927 µA µM−1 cm−2. The superior performance could be attributed to the higher active surface area of the SnSe/h-BN composite and a synergistic effect between SnSe and h-BN that enhances the kinetics of the electron transfer over the electrode–electrolyte interface. The SnSe/h-BN electrode also achieves a satisfactory response level for the detection of NF in water and urine samples, thus indicating its feasibility for the rapid, low-level detection, and real-time analysis of NF.

SnSe nanosheet arrays film for trace NO2 detection at room temperature

The development of high-performance room temperature sensors for detecting trace nitrogen dioxide (NO2) levels is critical for Internet of Things based environmental monitoring. We present a novel NO2 gas sensor based on tin selenide (SnSe) nanosheet arrays films deposited on a variety of substrates using vacuum thermal evaporation. The nanosheets formed well-oriented arrays and had a thickness of about 10 nm and lateral size of 0.2–1 µm. The films’ synthesis was well controlled, and the NO2 gas sensors’ performance was tuned by adjusting the microstructure of the films. The gas sensors were highly responsive to NO2 concentrations ranging from 100 to 300 ppb, it can achieve a response of 155% towards 300 ppb concentration of NO2 at room temperature; the gas sensing performance is affected by film thickness and microstructure. At a high NO2 gas concentration of 10 ppm, a response time of 12 s and response rate of 700% were achieved at room temperature. Furthermore, the high selectivity and repeatability of the SnSe nanosheet arrays film gas sensor were demonstrated. Because of its ease of fabrication and high performance, the NO2 gas sensor described here has promising applications.

Fabrication of SnSe2-graphene nanosheets for highly effectively electrocatalytic reduction of CO2

Electrocatalytic reduction of CO2 to formate is an extremely attractive route. Here, we developed a SnSe2-graphene composite catalyst, and SnSe2 nanosheets were linked to graphene by Sn-O-C bonds to form complicated hierarchical nanosheet structure. Due to the intrinsic activity of SnSe2 and the modification of graphene, the catalyst performed excellent electrocatalytic efficacy for the reduction of CO2 to formate, with a maximum Faraday efficiency up to 95.1% at -0.9 V (vs. RHE) and a current density of 11.8 mA cm−2 under the optimal conditions. Kinetic experiments indicated that the SnSe2-graphene composite achieved efficient formate selectivity for CO2 reduction by increasing the initial transfer rate of electrons to the CO2 molecule.

MAX-phase Derived Tin Diselenide for 2D/2D Heterostructures with Ultralow Surface/Interface Transport Barriers toward Li-/Na-ions Storage.

2D tin diselenide and its derived 2D heterostructures have delivered promising potentials in various applications ranging from electronics to energy storage devices. The major challenges associated with large-scale fabrication of SnSe2 crystals, however, have hindered its engineering applications. Herein, a tin-extraction synthetic method is proposed for producing large-size SnSe2 bulk crystals. In a typical synthesis, a Sn-containing MAX phase (V2 SnC) and a Se source are heat-treated under a reducing atmosphere, by which Sn is extracted from the V2 SnC phase as a rectified Sn source to form SnSe2 crystals in the cold zone. After the following liquid exfoliation, the obtained 2D SnSe2 nanosheets have a lateral size of a few centimeters and an atomic thickness. Furthermore, by coupling with 2D graphene to form 2D/2D SnSe2 /graphene heterostructured electrodes, as validated by theoretical calculation and experimental studies, the superior Li-/Na-ion storage performance with ultralow surface/interface ion transport barriers are achieved for rechargeable Li-/Na-ion batteries. This innovative synthetic strategy opens a new avenue for the large-scale synthesis of selenides and offers more options into the practical application of emerging 2D/2D heterostructure for electrochemical energy storage.

Solution processed 2D SnSe nanosheets catalysts: Temperature dependent oxygen reduction reaction performance in alkaline media

• Single phase SnSe synthesis with non-toxic Se precursor, the monetary synthetic route is employed. • The SnSe catalysts 4-electron pathway for oxygen reduction. • The current density and charge transfer number of SnSe-500 catalysts are 4.50 mA/cm 2 and 3.62. One of the most effective synthesis routes is the simple solution process, which is an inexpensive way to make single phase 2-Dimensional (2D) Tin Selenide (SnSe) nanosheets. X-ray diffraction (XRD), X-ray Photoelectron spectroscopy (XPS), and Field Emission Scanning Electron Microscope (FESEM) were used to confirm the structural and topographical investigations. 2D SnSe served for Oxygen Reduction Reaction (ORR) electrochemical performance in KOH solution. Later, 2D SnSe is annealed at 300, 400 and 500 °C later termed as SnSe-300, SnSe-400 and SnSe-500 respectively to investigate the electrochemical behavior of catalyst. As the temperature increases ORR performance improved. For the first time, 2- and 4-electron transfer pathway mechanism of SnSe catalysts is discussed. As enhancement in the performance of as prepared 2D SnSe catalysts ensured with various parameters like current density, electron charge transfer number and half-wave potential. SnSe-500 has a half-wave potential of −0.75 V, which is lower than other catalysts in this case. In addition, a current density of 4.50 mA/cm 2 was recorded, which is superior to other catalysts in this case.

Mechanically Induced Highly Efficient Hydrogen Evolution from Water over Piezoelectric SnSe nanosheets.

Piezoelectric nanomaterials open new avenues in driving green catalysis processes (e.g., H2 evolution from water) through harvesting mechanical energy, but their catalytic efficiency is still limited. The predicted enormous piezoelectricity for 2D SnSe, together with its high charge mobility and excellent flexibility, renders it an ideal candidate for stimulating piezocatalysis redox reactions. In this work, few-layer piezoelectric SnSe nanosheets (NSs) are utilized for mechanically induced H2 evolution from water. The finite elemental method simulation demonstrates an unprecedent maximal piezoelectric potential of 44.1V for a single SnSe NS under a pressure of 100MPa. A record-breaking piezocurrent density of 0.3mA cm-2 is obtained for SnSe NSs-based electrode under ultrasonic excitation (100 W, 45kHz), which is about three orders of magnitude greater than that of reported piezocatalysts. Moreover, an exceptional H2 production rate of 948.4 µmol g-1 h-1 is achieved over the SnSe NSs without any cocatalyst, far exceeding most of the reported piezocatalysts and competitive with the current photocatalysis technology. The findings not only enrich the potential piezocatalysis materials, but also provide useful guidance toward high-efficiency mechanically driven chemical reactions such as H2 evolution from water.

Designing Lactate Dehydrogenase-Mimicking SnSe Nanosheets To Reprogram Tumor-Associated Macrophages for Potentiation of Photothermal Immunotherapy.

Rapid glycolysis of tumor cells produces excessive lactate to trigger acidification of the tumor microenvironment (TME), leading to the formation of immunosuppressive TME and tumor-associated macrophage (TAM) dysfunction. Therefore, reprogramming TAMs by depleting lactate with nanodrugs is expected to serve as an effective means of tumor-targeted immunotherapy. Herein, we report the use of lactic acid dehydrogenase (LDH)-mimicking SnSe nanosheets (SnSe NSs) loaded with a carbonic anhydrase IX (CAIX) inhibitor to reconstruct an acidic and immunosuppressive TME. As expected, this nanosystem could reprogram the TAM to achieve M1 macrophage activation and could also restore the potent tumor-killing activity of macrophages while switching their metabolic mode from mitochondrial oxidative phosphorylation to glycolysis. In addition, the repolarizing effect of SnSe NSs on macrophages was validated in a coculture model of bone marrow-derived macrophages, in three patient-derived malignant pleural effusion and in vivo mouse model. This study proposes a feasible therapeutic strategy for depleting lactate and thus ameliorating acidic TME employing Se-containing nanosheets, which could further amply the effects of TAM-based antitumor immunotherapy.

Recent Advances in SnSe Nanostructures beyond Thermoelectricity

AbstractLayered SnSe is an emerging class of black phosphorus, which is non‐toxic, eco‐friendly, and chemically stable. Recently, SnSe nanostructures have triggered more research interest and enabled broad applications beyond demonstrating their great performances on thermoelectricity. However, there are also a great many significant studies of SnSe nanostructures beyond thermoelectricity. SnSe quantum dots, nanosheets, nanowires, and thin films with diverse morphologies have been synthesized using various chemical and physical preparation approaches. SnSe is a multi‐phase semiconductor, and its nanostructures endow unique properties, including small electron effective mass, ultralow thermal conductivity, huge anisotropy, and the largest 2D piezoelectric coefficient ever predicted. The versatility of SnSe nanostructures can enable potential applications ranging from ultrafast photonics, logic devices, photodetectors, solar cells, photocatalysis, energy storage, and biology to more cutting‐edge interdisciplinary subjects. In this review, the recent advances made in SnSe nanostructures are summarized, covering basics, synthesis, properties, and applications, just giving a passing comment on thermoelectricity. An in‐depth perspective on the challenges and prospects of SnSe nanostructures toward broad and practical applications is also given.

2D SnSe Cathode Catalyst Featuring an Efficient Facet‐Dependent Selective Li2O2 Growth/Decomposition for Li–Oxygen Batteries

Abstract2D materials are attracting much attention in the field of cathode catalysts for lithium–oxygen batteries (LOBs) due to their layered structure, unique electronic properties, and high stability. However, different stacking layer structures trigger different catalytic capabilities in LOBs. In this work, tin selenide nanosheets with a black phosphorus‐like 2D structure are synthesized and used as the cathode catalyst for LOBs. SnSe nanosheets with exposed stack (200) facets and stack edge facets exhibit superior specific capacity over 20 783 mAh g−1 and ultralong cycle stability over 380 cycles at 500 mA g−1 in LOBs. This demonstrates that the growth of discharge products is mainly concentrated on the 2D surface (200) facets, rather than the stack edge facets. Experimental and theoretical studies reveal that the confined adsorption of Li2O2 on the stack edge facets of SnSe, due to the 2D layer structure and the unique electron distribution, restricts the growth of discharge products. The 2D surface facets of SnSe benefit for the formation and stabilization of LiO2 intermediates, leading to the efficient formation/decomposition of discharge products. The findings provide in‐depth insight into the elusive electrocatalytic mechanism for 2D layer‐structures materials in LOBs.

Wide-spectrum polarization-sensitive and fast-response photodetector based on 2D group IV-VI semiconductor tin selenide

Tin selenide (SnSe) has attracted considerable interest recently on account of its low-symmetry lattice structure, great compatibility with key semiconductor technology, and remarkable electrical and optical performance. SnSe-based polarization-sensitive photodetectors show promising application prospects because of their fast response and excellent photoelectric performance. Here, an in-plane anisotropic SnSe nanosheet was synthesized and reported in detail by applying angle-resolved polarized Raman spectroscopy (ARPRS), polarization-resolved optical microscopy(PROM), angle-resolved optical absorption spectroscopy (AROAS), and other crystal structure characterization methods. Moreover, SnSe crystals exhibit superior polarization detection performance with a high anisotropic photocurrent ratio (2.31 at 1064 nm) due to the structure formed by the Van der Waals superposition of covalently bonded atomic layers. Furthermore, SnSe-based photodetectors have high responsivity (9.27 A/W), high detectivity (4.08 × 1010 Jones), and fast response (in the order of nanoseconds). These results suggest a new method for fabricating 2D fast-response polarization-sensitive photodetectors in the future.

Humidity-activated H2S sensor based on SnSe2/WO3 composite for evaluating the spoilage of eggs at room temperature

Hydrogen sulfide (H2S), as a representative food spoilage gas produced by the breakdown of sulfur-containing proteins, is highly irritant and toxic. Designing gas sensors sensitive to H2S for food spoilage evaluation is of great significance for automated quality control in the modern food industry. However, humidity in the environment can generally deteriorate the detection performance of conventional metal oxide semiconductor gas sensors. Therefore, it is critical to develop H2S sensors based on novel materials that can operate effectively in atmospheric humidity conditions. In this work, tin diselenide (SnSe2) nanosheets decorated with tungsten trioxide (WO3) nanoparticles are synthesized by a one-step ultrasound strategy, and used as sensing layers for H2S gas sensors. The water molecule activated charge-transfer of the SnSe2/WO3 composite boosts H2S sensing ability at high relative humidity (RH) levels. At room temperature (25 °C), the SnSe2/WO3 composite sensor with optimal mass ratio exhibits enhanced H2S response value (33.80%@10 ppm) compared with that of the pristine SnSe2 sensor (14.29%@10 ppm) at 82% RH. In addition, the fabricated sensor is proven to be practically effective for evaluating the spoilage of eggs by comparing the sensing response of a fresh egg with that of a spoiled egg. This study offers possibilities for evaluating the spoilage of foods in poultry, aquatic, and food processing industries using a rapid and sensitive humidity-activated H2S gas sensor.