This article describes a robust method for the facile synthesis of small Ag nanocubes with edge lengths controlled in the range of 18–32 nm. The success of this new method relies on the substitution of ethylene glycol (EG) -- the solvent most commonly used in a polyol synthesis -- with diethylene glycol (DEG). Owing to the increase in hydrocarbon chain length, DEG possesses a higher viscosity and a lower reducing power relative to EG. As a result, we were able to achieve a nucleation burst in the early stage to generate a large number of seeds and a relatively slow growth rate thereafter; both factors were critical to the formation of Ag nanocubes with small sizes and in high purity (>95%). The edge length of the Ag nanocubes could be easily tailored in the range of 18–32 nm by quenching the reaction at different time points. For the first time, we were able to produce uniform sub-20 nm Ag nanocubes in a hydrophilic medium and on a scale of ~20 mg per batch. It is also worth pointing out that the present protocol was remarkably robust, showing good reproducibility between different batches and even for DEGs obtained from different vendors. Our results suggest that the high sensitivity of synthesis outcomes to the trace amounts of impurities in a polyol, a major issue for reproducibility and scale up synthesis, did not exist in the present system.

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2D transition metal dichalcogenide (TMD) materials have been recognized as active platforms for surface‐enhanced Raman spectroscopy (SERS). Here, the effect of crystal structure (phase) transition is shown, which leads to altered electronic structures of TMD materials, on the Raman enhancement. Using thermally evaporated copper phthalocyanine, solution soaked rhodamine 6G, and crystal violet as typical probe molecules, it is found that a phase transition from 2H‐ to 1T‐phase can significantly increase the Raman enhancement effect on MoX2 (X = S, Se) monolayers through a predominantly chemical mechanism. First‐principle density functional theory calculations indicate that the significant enhancement of the Raman signals on metallic 1T‐MoX2 can be attributed to the facilitated electron transfer from the Fermi energy level of metallic 1T‐MoX2 to the highest occupied molecular orbital level of the probe molecules, which is more efficient than the process from the top of valence band of semiconducting 2H‐MoX2. This study not only reveals the origin of the Raman enhancement and identifies 1T‐MoSe2 and 1T‐MoS2 as potential Raman enhancement substrates, but also paves the way for designing new 2D SERS substrates via phase‐transition engineering.

Sodium‐ion batteries are emerging as promising candidates for grid energy storage because of the abundant sodium resources and low cost. However, the identification and development of suitable anode materials is far from being satisfactory. Here, it is demonstrated that the Ti2Nb2O9 nanosheets with tunnel structure can be used as suitable anode materials for sodium‐ion batteries. Ti2Nb2O9 nanosheets are synthesized by liquid exfoliation combined with topotactic dehydration, delivering a high reversible capacity of 250 mAh g−1 at 50 mA g−1 at a suitable average voltage of ≈0.7 V. It is found that a low energy diffusion barrier, enlarged interlayer spacing, and exceptional nanoporosity together give rise to high rate performance characterized by pseudocapacitive behavior. The observed high reversible capacity, excellent rate capability, and good cyclability of Ti2Nb2O9 nanosheets make this material competitive when compared to other sodium insertion anode materials.

The adherence of bacteria and the formation of biofilm on implants is a serious problem that often leads to implant failure. A series of antimicrobial coatings have been constructed to resist bacterial adherence or to kill bacteria through contact with or release of antibacterial agents. The accumulation of dead bacteria facilitates further bacterial contamination and biofilm development. Herein, we have designed and constructed a novel, reversibly switchable bactericidal and antifouling surface through surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization to combine thermally responsive N-isopropylacrylamide (NIPAAm) and bactericidal quaternary ammonium salts (2-(dimethylamino)-ethyl methacrylate (DMAEMA)). Measurements of spectroscopic ellipsometry and water contact angle and X-ray photoelectron spectroscopy were used to examine the process of the surface functionalization. The temperature-responsive P(DMAEMA-co-NIPAAm) copolymer coating can switch by phase transition between a hydrophobic capturing surface at high temperatures and a relatively hydrophilic antifouling surface at lower temperatures. The quaternary ammonium salts of PDMAEMA displayed bactericidal efficiency against both Escherichia coli and Staphylococcus aureus. The functionalized surface could efficiently prevent bovine serum albumin adsorption and had good biocompatibility against human lens epithelial cells.

For green production of iron ore sintering, it is significant to substitute fossil fuels by biomass which is a kind of clean and renewable energy. In this paper, three kinds of biomass fuels such as charcoal, charred-straw and molded-sawdust were studied as sintering fuels. The results show that, with the proportion of biomass replacing coke breeze increasing, the vertical sintering speed raises, but the yield and the tumble index of sinter decrease, so the replacement proportion should be appropriate for satisfying the productivity and the quality of sinter. The suitable replacing proportions of charcoal, charred-straw and molded-sawdust are 40%, 20% and 15% respectively, in which the emission of COx can be decreased by 18.65%, 7.19% and 5.39%, SOx by 38.15%, 31.79% and 28.90%, NOx by 26.76%, 18.31% and 15.49% respectively.

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