This paper reports the facile synthesis of a unique interleaved expanded graphite-embedded sulphur nanocomposite (S-EG) by melt-diffusion strategy. The SEM images of the S-EG materials indicate the nanocomposites consist of nanosheets with a layer-by-layer structure. Electrochemical tests reveal that the nanocomposite with a sulphur content of 60% (0.6S-EG) can deliver the highest discharge capacity of 1210.4 mAh g À1 at a charge-discharge rate of 280 mA g À1 in the first cycle, the discharge capacity of the 0.6S-EG remains as high as 957.9 mAh g À1 after 50 cycles of charge-discharge. Furthermore, at a much higher charge-discharge rate of 28 A g À1 , the 0.6S-EG cathode can still deliver a high reversible capacity of 337.5 mAh g À1 . The high sulphur utilization, excellent rate capability and reduced overdischarge phenomenon of the 0.6S-EG material are exclusively attributed to the particular microstructure and composition of the cathode.

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Kinetically controlled, seed-mediated co-reduction provides a robust and versatile synthetic approach to multimetallic nanoparticles with precisely controlled geometries and compositions. Here, we demonstrate that single-crystalline cylindrical Au nanorods selectively transform into a series of structurally distinct Au@Au-Pd alloy core-shell bimetallic nanorods with exotic multifaceted geometries enclosed by specific types of facets upon seed-mediated Au-Pd co-reduction under diffusion-controlled conditions. By adjusting several key synthetic parameters, such as the Pd/Au precursor ratio, the reducing agent concentration, the capping surfactant concentration, and foreign metal ion additives, we have been able to simultaneously fine-tailor the atomic-level surface structures and fine-tune the compositional stoichiometries of the multifaceted Au-Pd bimetallic nanorods. Using the catalytic hydrogenation of 4-nitrophenol by ammonia borane as a model reaction obeying the Langmuir-Hinshelwood kinetics, we further show that the relative surface binding affinities of the reactants and the rates of interfacial charge transfers, both of which play key roles in determining the overall reaction kinetics, strongly depend upon the surface atomic coordinations and the compositional stoichiometries of the colloidal Au-Pd alloy nanocatalysts. The insights gained from this work not only shed light on the underlying mechanisms dictating the intriguing geometric evolution of multimetallic nanocrystals during seed-mediated co-reduction but also provide an important knowledge framework that guides the rational design of architecturally sophisticated multimetallic nanostructures toward optimization of catalytic molecular transformations.

Optical excitation of plasmonic electron oscillations confined by metallic nanoparticles provides a unique means of driving unconventional photocatalytic transformations of molecular adsorbates on the nanoparticle surfaces. Photothermal heating, local-field enhancement, and hot carrier generation have been identified as three major plasmon-induced photophysical effects, all of which are directly relevant to plasmon-driven photocatalysis. However, delineation of the contribution of each effect has long been challenging due to the strong synergy among the three effects and the mechanistic complexity of plasmon-driven molecular transformations. Aiming at unambiguously elucidating the photothermal effect, local-field dependence, and hot carrier channeling mechanisms that underpin plasmondriven photocatalysis, we conducted a detailed case study on the aerobic reductive coupling of p-nitrothiophenol chemisorbed on Ag nanocube surfaces under near-infrared excitations. We used surface-enhanced Raman scattering (SERS) as a plasmon-enhanced, molecular fingerprinting spectroscopic tool to track the plasmon-driven structural evolution of molecular adsorbates in real time, based on which we were able to correlate the molecule-transforming kinetics with local-field intensities and photothermal heating at the nanoparticle surfaces. The information extracted from the time-resolved SERS results allowed us not only to clarify several controversial issues regarding the photothermal effect and local field dependence but also to unravel a unique function of surface-adsorbed molecular oxygen as an interfacial charge carrier relaying cocatalyst that works in conjunction with the plasmonic Ag photocatalysts to mediate the multistep coupling reaction.

Plasmonic nanoparticles with an intrinsic chiral structure have emerged as a promising chiral platform for applications in biosensing, medicine, catalysis, separation, and photonics. Quantitative understanding of the correlation between nanoparticle structure and optical chirality becomes increasingly important but still represents a significantly challenging task. Here we demonstrate that tunable signal reversal of circular dichroism in the seed-mediated chiral growth of plasmonic nanoparticles can be achieved through the hybridization of bichiral centers without inverting the geometric chirality. Both experimental and theoretical results demonstrated the opposite sign of circular dichroism of two different bichiral geometries. Chiral molecules were found to not only contribute to the chirality transfer from molecules to nanoparticles but also manipulate the structural evolution of nanoparticles that synergistically drive the formation of two different chiral centers. By deliberately adjusting the concentration of chiral molecules and other synthetic parameters, such as the reducing agent concentration, the capping surfactant concentration, and the amount of Au precursor, we have been able to fine-tune the circular dichroism reversal of bichiral Au nanoparticles. We further demonstrate that the structure of chiral molecules and the crystal structure of Au seeds play crucial roles in the formation of Au nanoparticles with bichiral centers. The insights gained from this work not only shed light on the underlying mechanisms dictating the intriguing geometric and chirality evolution of bichiral plasmonic nanoparticles but also provide an important knowledge framework that guides the rational design of bichiral plasmonic nanostructures toward chiroptical applications.