Aluminium substitution in Sb2S3 nanorods enhances the stability of the microstructure and high-rate capability in the alloying regime

Alloy anodes, with twice the capacity of graphite, are promising for next-generation lithium-ion batteries (LIBs). However, poor rate-capability and cycling stability, mainly due to pulverization, have limited their application. By constraining the cutoff voltage to the alloying regime (1 V to 10 mV vs. Li/Li⁺), we show that Sb_1.9Al_0.1S₃ nanorods provide excellent electrochemical performance, with an initial capacity of ∼450 mA h g^-1 and excellent cycling stability with 63% retention (capacity ∼240 mA h g^-1 after 1000 cycles at 5C-rate), unlike 71.4 mA h g^-1 after 500 cycles observed in full-regime cycling. When conversion cycling is also involved the capacity degrades faster (<20% retention after 200 cycles) irrespective of Al doping. The contribution of alloy storage to total capacity is always larger than the conversion storage indicating the superiority of the former. The formation of crystalline Sb(Al) is noted in Sb_1.9Al_0.1S₃, unlike amorphous Sb in Sb₂S₃. Retention of the nanorod microstructure in Sb_1.9Al_0.1S₃ despite the volume expansion enhances the performance. On the contrary, the Sb₂S₃ nanorod electrode gets pulverized and the surface shows microcracks. Percolating Sb nanoparticles buffered by the Li₂S matrix and other polysulfides enhance the performance of the electrode. These studies pave the way for high-energy and high-power density LIBs with alloy anodes.

Bimetallic Sulfide Sb2S3@FeS2 Hollow Nanorods as High-Performance Anode Materials for Sodium-Ion Batteries

Constructing a heterojunction and introducing an interfacial interaction by designing ideal structures have the inherent advantages of optimizing electronic structures and macroscopic mechanical properties. An exquisite hierarchical heterogeneous structure of bimetal sulfide Sb₂S₃@FeS₂ hollow nanorods embedded into a nitrogen-doped carbon matrix is fabricated by a concise two-step solvothermal method. The FeS₂ interlayer expands in situ grow on the interface of hollow Sb₂S₃ nanorods within the nitrogen-doped graphene matrix, forming a delicate heterostructure. Such a well-designed architecture affords rapid Na⁺ diffusion and improves charge transfer at the heterointerfaces. Meanwhile, the strongly synergistic coupling interaction among the interior Sb₂S₃, interlayer FeS₂, and external nitrogen-doped carbon matrix creates a stable nanostructure, which extremely accelerates the electronic/ion transport and effectively alleviates the volume expansion upon long cyclic performance. As a result, the composite, as an anode material for sodium-ion batteries, exhibits a superior rate capability of 537.9 mAh g^-1 at 10 A g^-1 and excellent cyclic stability with 85.7% capacity retention after 1000 cycles at 5 A g^-1. Based on the DFT calculation, the existing constructing heterojunction in this composite can not only optimize the electronic structure to enhance the conductivity but also favor the Na₂S adsorption energy to accelerate the reaction kinetics. The outstanding electrochemical performance sheds light on the strategy by the rational design of hierarchical heterogeneous nanostructures for energy storage applications.

Colloidal Antimony Sulfide Nanoparticles as a High-Performance Anode Material for Li-ion and Na-ion Batteries

To maximize the anodic charge storage capacity of Li-ion and Na-ion batteries (LIBs and SIBs, respectively), the conversion-alloying-type Sb2S3 anode has attracted considerable interest because of its merits of a high theoretical capacity of 946 mAh g-1 and a suitable anodic lithiation/delithiation voltage window of 0.1-2 V vs. Li+/Li. Recent advances in nanostructuring of the Sb2S3 anode provide an effective way of mitigating the challenges of structure conversion and volume expansion upon lithiation/sodiation that severely hinder the Sb2S3 cycling stability. In this context, we report uniformly sized colloidal Sb2S3 nanoparticles (NPs) as a model Sb2S3 anode material for LIBs and SIBs to investigate the effect of the primary particle size on the electrochemical performance of the Sb2S3 anode. We found that compared with microcrystalline Sb2S3, smaller ca. 20-25 nm and ca. 180-200 nm Sb2S3 NPs exhibit enhanced cycling stability as anode materials in both rechargeable LIBs and SIBs. Importantly, for the ca. 20-25 nm Sb2S3 NPs, a high initial Li-ion storage capacity of 742 mAh g-1 was achieved at a current density of 2.4 A g-1. At least 55% of this capacity was retained after 1200 cycles, which is among the most stable performance Sb2S3 anodes for LIBs.

Template-Free Synthesis of Sb2S3 Hollow Microspheres as Anode Materials for Lithium-Ion and Sodium-Ion Batteries

Hierarchical Sb₂S₃ hollow microspheres assembled by nanowires have been successfully synthesized by a simple and practical hydrothermal reaction. The possible formation process of this architecture was investigated by X-ray diffraction, focused-ion beam-scanning electron microscopy dual-beam system, and transmission electron microscopy. When used as the anode material for lithium-ion batteries, Sb₂S₃ hollow microspheres manifest excellent rate property and enhanced lithium-storage capability and can deliver a discharge capacity of 674 mAh g^-1 at a current density of 200 mA g^-1 after 50 cycles. Even at a high current density of 5000 mA g^-1, a discharge capacity of 541 mAh g^-1 is achieved. Sb₂S₃ hollow microspheres also display a prominent sodium-storage capacity and maintain a reversible discharge capacity of 384 mAh g^-1 at a current density of 200 mA g^-1 after 50 cycles. The remarkable lithium/sodium-storage property may be attributed to the synergetic effect of its nanometer size and three-dimensional hierarchical architecture, and the outstanding stability property is attributed to the sufficient interior void space, which can buffer the volume expansion.

Near-infrared-driven Cr(vi) reduction in aqueous solution based on a MoS2/Sb2S3 photocatalyst

A novel MoS₂/Sb₂S₃ composite with enhanced near-infrared photocatalytic efficiency was fabricated.

High rate capability and superior cycle stability of a flower-like Sb2S3 anode for high-capacity sodium ion batteries

Flower-like antimony sulfide structures were prepared by a simple and easy polyol reflux process. When tested as an anode for sodium ion batteries, the material delivered a high reversible capacity of 835.3 mA h g(-1) at 50 mA g(-1) after 50 cycles and maintained a capacity of 641.7 mA h g(-1) at 200 mA g(-1) after 100 cycles. Even up to 2000 mA g(-1), a capacity of 553.1 mA h g(-1) was obtained, indicating an excellent cycle performance and a superior rate capability. The mechanism of the formation of the micro-flowers was also investigated. The additive used facilitates the controlled release of the reactant to form uniform, shaped nanosheets and an optimum reaction time allows the nanosheets to self-assemble into micro-flowers.

Electrospun In@C nanofibers as a superior Li-ion battery anode

In this communication, we have successfully obtained electrospun indium@carbon nanofibers. When applied as the Li-ion battery anode, the indium@carbon nanofibers could exhibit a high discharge capacity of 500 mA h g⁻¹ after 200 cycles at 100 mA g⁻¹.

Controlled fabrication of hierarchical WO3·H2O hollow microspheres for enhanced visible light photocatalysis

A new type of hierarchical WO₃·H₂O hollow microsphere, whose formation was successfully controlled based on the reaction system for preparing simple nanoplates, showed excellent photocatalytic activity for the degradation of dye under visible light.

Nanostructured metal sulfides for energy storage

Advanced electrodes with a high energy density at high power are urgently needed for high-performance energy storage devices, including lithium-ion batteries (LIBs) and supercapacitors (SCs), to fulfil the requirements of future electrochemical power sources for applications such as in hybrid electric/plug-in-hybrid (HEV/PHEV) vehicles. Metal sulfides with unique physical and chemical properties, as well as high specific capacity/capacitance, which are typically multiple times higher than that of the carbon/graphite-based materials, are currently studied as promising electrode materials. However, the implementation of these sulfide electrodes in practical applications is hindered by their inferior rate performance and cycling stability. Nanostructures offering the advantages of high surface-to-volume ratios, favourable transport properties, and high freedom for the volume change upon ion insertion/extraction and other reactions, present an opportunity to build next-generation LIBs and SCs. Thus, the development of novel concepts in material research to achieve new nanostructures paves the way for improved electrochemical performance. Herein, we summarize recent advances in nanostructured metal sulfides, such as iron sulfides, copper sulfides, cobalt sulfides, nickel sulfides, manganese sulfides, molybdenum sulfides, tin sulfides, with zero-, one-, two-, and three-dimensional morphologies for LIB and SC applications. In addition, the recently emerged concept of incorporating conductive matrices, especially graphene, with metal sulfide nanomaterials will also be highlighted. Finally, some remarks are made on the challenges and perspectives for the future development of metal sulfide-based LIB and SC devices.

Gas sensing of SnO2 nanocrystals revisited: developing ultra-sensitive sensors for detecting the H2S leakage of biogas

As a typical mode of energy from waste, biogas technology is of great interest to researchers. To detect the trace H2S released from biogas, we herein demonstrate a high-performance sensor based on highly H2S-sensitive SnO2 nanocrystals, which have been selectively prepared by solvothermal methods using benzimidazole as a mineralization agent. The sensitivity of as-obtained SnO2 sensor towards 5 ppm H2S can reach up to 357. Such a technique based on SnO2 nanocrystals opens up a promising avenue for future practical applications in real-time monitoring a trace of H2S from the leakage of biogas.

Bulk antimony sulfide with excellent cycle stability as next-generation anode for lithium-ion batteries

Nanomaterials as anode for lithium-ion batteries (LIB) have gained widespread interest in the research community. However, scaling up and processibility are bottlenecks to further commercialization of these materials. Here, we report that bulk antimony sulfide with a size of 10-20 μm exhibits a high capacity and stable cycling of 800 mAh g(-1). Mechanical and chemical stabilities of the electrodes are ensured by an optimal electrode-electrolyte system design, with a polyimide-based binder together with fluoroethylene carbonate in the electrolyte. The polyimide binder accommodates the volume expansion during alloying process and fluoroethylene carbonate suppresses the increase in charge transfer resistance of the electrodes. We observed that particle size is not a major factor affecting the charge-discharge capacities, rate capability and stability of the material. Despite the large particle size, bulk antimony sulfide shows excellent rate performance with a capacity of 580 mAh g(-1) at a rate of 2000 mA g(-1).

α-Fe2O3 nanochains: ammonium acetate-based ionothermal synthesis and ultrasensitive sensors for low-ppm-level H2S gas

α-Fe(2)O(3) nanochains have been successfully synthesized via an ammonium acetate-based ionothermal synthetic route. When detecting low-ppm-level H(2)S gas, the nanochain sensor displayes high sensitivity due to its unique structure and smaller size.

Urchinlike nanostructure of single-crystalline nanorods of Sb2S3 formed at mild reaction condition

Urchinlike nanostructure of well-defined Sb(2)S(3) crystals of 3-4 μm in length and 30-150 nm in diameter oriented along [001] direction have been produced at a mild reaction temperature of 90 °C from SbCl(3) and S-methyl 3-phenyldithiocarbazate [C(6)H(5)NHNHC(S)SMe] in ethylene glycol medium. During the reaction, the amorphous Sb(2)S(3) spheres of 1.4 μm in diameter were formed at early reaction stage and then crystalline nanorods were continuously grown at the surface of Sb(2)S(3) spheres while transforming their morphology into urchinlike structure. The urchinlike Sb(2)S(3) was composed of single-crystalline Sb(2)S(3) nanorods, belong to the orthorhombic phase with cell parameters a = 11.307 Å, b = 11.278 Å, c = 3.847 Å and absorbed the light up to 750 nm-wavelength region. The urchinlike Sb(2)S(3) architecture was applied to the photoelectrochemical cell.

Ionothermal synthesis of aggregated α-Fe₂O₃ nanoplates and their magnetic properties

Aggregated α-Fe(2)O(3) nanoplates have been successfully synthesized under ionothermal conditions through the self-assembly of nanoplatelets in a side-to-side manner. During the formation process of aggregated α-Fe(2)O(3) nanoplates, pure ionic liquid media is essential for the assembly and coalescence of small nanoplatelets into final nanoplates. Moreover, the magnetic properties of the aggregated α-Fe(2)O(3) nanoplates are strongly correlated to their unique structural characteristics.

Bi2S3 nanomaterials: morphology manipulation and related properties

The Bi(2)S(3) nanomaterials with various morphologies such as nanorods, nanowires, nanowire bundles, urchin-like microspheres and urchin-like microspheres with cavities have been successfully synthesized through a simple hydrothermal method. Experimental results indicate that sulfur sources play crucial roles in determining the morphologies of Bi(2)S(3) products. Moreover, formation mechanisms of different Bi(2)S(3) nanostructures are discussed based on understanding of the growth habit of Bi(2)S(3) crystal. Finally, we also studied the morphologies-dependent electrochemical and optical properties of the as-synthesized Bi(2)S(3) nanomaterials.