Low‐Temperature Solution‐Based Phosphorization Reaction Route to Sn4P3/Reduced Graphene Oxide Nanohybrids as Anodes for Sodium Ion Batteries

Different from previously reported mechanical alloying route to synthesize Sn _x P₃, novel Sn₄P₃/reduced graphene oxide (RGO) hybrids are synthesized for the first time through an in situ low‐temperature solution‐based phosphorization reaction route from Sn/RGO. Sn₄P₃ nanoparticles combining with advantages of high conductivity of Sn and high capacity of P are homogenously loaded on the RGO nanosheets, interconnecting to form 3D mesoporous architecture nanostructures. The Sn₄P₃/RGO hybrid architecture materials exhibit significantly improved electrochemical performance of high reversible capacity, high‐rate capability, and excellent cycling performance as sodium ion batteries (SIBs) anode materials, showing an excellent reversible capacity of 656 mA h g^?1 at a current density of 100 mA g^?1 over 100 cycles, demonstrating a greatly enhanced rate capability of a reversible capacity of 391 mA h g^?1 even at a high current density of 2.0 A g^?1. Moreover, Sn₄P₃/RGO SIBs anodes exhibit a superior long cycling life, delivering a high capacity of 362 mA h g^?1 after 1500 cycles at a high current density of 1.0 A g^?1. The outstanding cycling performance and rate capability of these porous hierarchical Sn₄P₃/RGO hybrid anodes can be attributed to the advantage of porous structure, and the synergistic effect between Sn₄P₃ nanoparticles and RGO nanosheets.     

Outstanding Low Temperature Thermoelectric Power Factor from Completely Organic Thin Films Enabled by Multidimensional Conjugated Nanomaterials

In an effort to create a paintable/printable thermoelectric material, comprised exclusively of organic components, polyaniline (PANi), graphene, and double‐walled nanotube (DWNT) are alternately deposited from aqueous solutions using the layer‐by‐layer assembly technique. Graphene and DWNT are stabilized with an intrinsically conductive polymer, poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). An 80 quadlayer thin film (≈1 μm thick), comprised of a PANi/graphene‐PEDOT:PSS/PANi/DWNT‐PEDOT:PSS repeating sequence, exhibits unprecedented electrical conductivity (σ ≈ 1.9 × 10⁵ S m^?1) and Seebeck coefficient (S ≈ 120 μV K^?1) for a completely organic material. These two values yield a thermoelectric power factor (PF = S ² σ ^?1) of 2710 μW m^?1 K^?2, which is the highest value ever reported for a completely organic material and among the highest for any material measured at room temperature. These outstanding properties are attributed to the highly ordered structure in the multilayer assembly. This water‐based thermoelectric nanocomposite is competitive with the best inorganic semiconductors (e.g., bismuth telluride) at room temperature and can be applied as a coating to any flexible surface (e.g., fibers in clothing). For the first time, there is a real opportunity to harness waste heat from unconventional sources, such as body heat, to power devices in an environmentally‐friendly way.     

Transition from Diffusion‐Controlled Intercalation into Extrinsically Pseudocapacitive Charge Storage of MoS2 by Nanoscale Heterostructuring

2D nanomaterials have been found to show surface‐dominant phenomena and understanding this behavior is crucial for establishing a relationship between a material's structure and its properties. Here, the transition of molybdenum disulfide (MoS₂) from a diffusion‐controlled intercalation to an emergent surface redox capacitive behavior is demonstrated. The ultrafast pseudocapacitive behavior of MoS₂ becomes more prominent when the layered MoS₂ is downscaled into nanometric sheets and hybridized with reduced graphene oxide (RGO). This extrinsic behavior of the 2D hybrid is promoted by the fast Faradaic charge‐transfer kinetics at the interface. The heterostructure of the 2D hybrid, as observed via high‐angle annular dark field–scanning transmission electron microscopy and Raman mapping, with a 1T MoS₂ phase at the interface and a 2H phase in the bulk is associated with the synergizing capacitive performance. This 1T phase is stabilized by the interactions with the RGO. These results provide fundamental insights into the surface effects of 2D hetero‐nanosheets on emergent electrochemical properties.