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[Display omitted] Researchers are interested in single-atom catalysts with atomically scattered metals relishing the enhanced electrocatalytic activity for nitrogen reduction and 100 % metal atom utilization. In this paper, we investigated 18 transition metals (TM) spanning 3d to 5d series as efficient nitrogen reduction reaction (NRR) catalysts on defective 2D SiP V layered structures through first-principles calculation. A systematic screening identified Mo@SiP V , Nb@SiP V , Ta@SiP V and W@SiP V as superior, demonstrating enhanced ammonia synthesis with significantly lower limiting potentials (−0.25, −0.45, −0.49 and −0.15 V, respectively), compared to the benchmark −0.87 eV for the defective SiP. In addition, the descriptor Δ G *N was introduced to establish the relationship between the different NRR intermediates, and the volcano plot of the limiting potentials were determined for their potential-determining steps (PDS). Remarkably, the limiting voltage of the NRR possesses a good linear relationship with the active center TM atom Ɛ d , which is a reliable descriptor for predicting the limiting voltage. Furthermore, we verified the stability (using Ab Initio Molecular Dynamics − AIMD) and high selectivity (U L (NRR)- U L (HER) > -0.5 V) of these four catalysts in vacuum and solvent environments. This study systematically demonstrates the strong catalytic potential of 2D TM@SiP V (TM = Mo, Nb, Ta, W) single-atom catalysts for nitrogen reduction electrocatalysis. [ABSTRACT FROM AUTHOR]

[Display omitted] Iron sulfides have shown great potential as anode materials for sodium-ion batteries (SIBs) because of their high sodium storage capacity and low cost. Nevertheless, iron sulfides generally exhibit unsatisfied electrochemical performance induced by sluggish electron/ion transfer and severe pulverization upon the sodiation/desodiation process. Herein, we constructed a yolk-shell FeS@NC nanosphere with an N-doped carbon shell and FeS particle core via a simple hydrothermal method, followed by in-situ polymerization and vulcanization. The FeS particles intimately coupled with N-doped carbon can accelerate the electron transfer, avoid severe volume expansion, and maintain structural stability upon repeated sodiation/desodiation process. Furthermore, the small particle size of FeS can shorten ion-diffusion distance and facilitate ion transportation. Therefore, the FeS@NC nanosphere shows excellent cycling performance and superior rate capability that it can deliver a high capacity of 520.1 mAh g−1 over 800 cycles at 2.0 A g−1 and a remarkable capacity of 625.9 mAh g−1 at 10.0 A g−1. [ABSTRACT FROM AUTHOR]

[Display omitted] Metal sulfides (MSs) have attracted much attention as anode materials for sodium-ion batteries (SIBs) due to their high sodium storage capacity. However, the unsatisfactory electrochemical performance induced by the huge volume change and sluggish kinetics hampered the practical application of SIBs. Herein, guided by the heterostructure interface engineering, novel multicomponent metal sulfide-based anodes, including SnS, FeS, and Fe 3 N embedded in N -doped carbon nanosheets (SnS/FeS/Fe 3 N/NC NSs), have been synthesized for high-performance SIBs. The as-prepared SnS/FeS/Fe 3 N/NC NSs with abundant heterointerfaces and high conductivity of N -doped carbon nanosheet matrix can shorten the Na+ diffusion path and promote reaction kinetics during the sodiation/desodiation process. Moreover, the presence of Fe 3 N can promote the reversible conversion of SnS and FeS during the cycling process. As a consequence, when evaluated as anode materials for SIBs, the SnS/FeS/Fe 3 N/NC NSs can maintain a high sodium storage capacity of 473.6 mAh g-1 after 600 cycles at 2.0 A g-1 and can still provide a high reversible capacity of 537.4 mAh g-1 even at 5.0 A g-1 This discovery offers a novel strategy for constructing metal sulfide-based anode materials for high-performance SIBs. [ABSTRACT FROM AUTHOR]

[Display omitted] A high-temperature-resistance insulating layer with high thermal conductivity is the key component for fabricating the instant metal-based electric heating tube. However, it is still a challenge for materials to possess excellent high-temperature resistance, superior insulating property, and high thermal conductivity at the same time. Here, a novel SiO 2 bridged AlN/MSR composite based on methylphenyl silicone resin (MSR) and AlN filler was reported. MSR with a high thermal decomposition temperature of 452.0 °C and a high withstand voltage of 5.6 kV was first synthesized by adjusting the contents of alkyl and phenyl groups. The superior high-temperature resistant insulating property is 3.7 and 2.4 times higher than the national standard requirement of 1.5 kV and commercial silicone resin, respectively. The hydrogen bonds formed between SiO 2 , AlN, and MSR and the electrostatic adsorption between SiO 2 and AlN can remarkably improve the uniform dispersion of AlN in MSR and thus enhance the insulating property, thermal conductivity, and thermal stability. With the addition of 2 wt% SiO 2 and 50 wt% AlN, the SiO 2 -AlN/MSR composite exhibits an extremely high withstand voltage of 7.3 kV, a high thermal conductivity of 0.553 W·m−1·K−1, and an enhanced decomposition temperature of 475 °C. The superior insulating property and thermal conductivity are 4.9 and 1.3 times higher than the national standard requirement and pure MSR, respectively. This novel composite shows great potential for application in the fields requiring integrated superior insulating property, high-temperature resistance, and high thermal conductivity. [ABSTRACT FROM AUTHOR]

The trimetallic sulfides heterostructure coated with N -doped carbon nanorods shows outstanding electrochemical performance. [Display omitted] Metal sulfides have been considered promising anode materials for lithium-ion batteries (LIBs), due to their high capacity. However, the poor cycle stability induced by the sluggish kinetics and poor structural stability hampers their practical application in LIBs. In this work, MoS 2 /MnS/SnS trimetallic sulfides heterostructure coated with N -doped carbon nanorods (MMSS@NC) is designed through a simple method involving co-precipitation, metal chelate-assisted reaction, and in-situ sulfurization method. In such designed MMSS@NC, a synergetic effect of heterojunctions and carbon layer is simultaneously constructed, which can significantly improve ionic and electronic diffusion kinetics, as well as maintain the structural stability of MMSS@NC during the repeated lithiation/delithiation process. When applied as anode materials for LIBs, the MMSS@NC composite shows superior long-term cycle performance (1145.0 mAh/g after 1100 cycles at 1.0 A/g), as well as excellent rate performance (565.3 mAh/g at 5.0 A/g). This work provides a unique strategy for the construction of multiple metal sulfide anodes for high-performance LIBs. [ABSTRACT FROM AUTHOR]

[Display omitted] Silicon (Si), have been considered as promising anode material for lithium-ion batteries (LIBs), due to its high theoretical specific capacity of 4200 mAh g−1. However, the poor electrical conductivity and large volume change during lithiation/delithiation process, resulting in poor cycling stability, and seriously hindered the practical application in LIBs. Herein, a multiple Si/Fe x Si y @NC/CNTs composite is synthesized and investigated as advanced anode materials for LIBs via a simple one-step method. Such multiple Si/Fe x Si y @NC/CNTs composite has several merits including the Fe x Si y can not only accommodate the huge volume change of Si nanoparticles, but also enhance the conductivity upon discharge/charge process. Furthermore, the in-situ growth CNTs may help establish a long-range conductivity, and the Nitrogen-doped carbon (NC) layer can further improve the conductivity of Si, as well as inhibit the direct contract between electrolyte and Si during cycling process. Accordingly, the Si/Fe x Si y @NC/CNTs-1 exhibits excellent cycling stability (a high capacity of 994.4 mAh g−1 is maintained at 1.0 A g−1 after 600cycles) and outstanding rate capability (a suitable capacity of 441.7 mAh g−1 was obtained even at 5.0 A g−1). Moreover, the assembled full cell can achieve a capacity of 141.4 mAh g−1 after 65 cycles at 1.0C, exhibiting outstanding cycling stability. This work provides a prospective way for the commercial production of high-performance Si-based anode materials for LIBs. [ABSTRACT FROM AUTHOR]