A Hybrid Assembly of MXene with NH2−Si Nanoparticles Boosting Lithium Storage Performance

A facile hybrid assembly between Ti₃C₂T_x MXene nanosheets and (3‐aminopropyl) triethoxylsilane‐modified Si nanoparticles (NH₂?Si NPs) was developed to construct multilayer stacking of Ti₃C₂T_x nanosheets with NH₂?Si NPs assembling together (NH₂?Si/Ti₃C₂T_x). NH₂?Si/Ti₃C₂T_x exhibits a significantly enhanced lithium storage performance compared to pristine Si, which is attributed to the robust crosslinking architecture and considerably improved electrical conductivity as well as shorter Li⁺ diffusion pathways. The optimized NH₂?Si/Ti₃C₂T_x anode with Ti₃C₂T_x: NH₂?Si mass ratio of 4 : 1 displays an enhanced capacity (864 mAh g^?1 at 0.1 C) with robust capacity retention, which is significantly higher than those of NH₂?Si NPs and Ti₃C₂T_x anodes. Furthermore, this work demonstrates the important effect of the MXene‐based electrode architecture on the electrochemical performance and can guide future work on designing high‐performance Si/MXene hybrids for energy storage applications.     

Quantitative characterization of holographic displays based on liquid-crystal-on-silicon spatial light modulator

This report discusses the effect of speckle size on the quality of holographic images based on a liquid-crystal-on-silicon (LCoS) spatial light modulator (SLM). Further, it proposes methods of quantifying the average speckle size and holographic image resolution. These methods enable both characteristics to be compared using the same unit (the number of pixels in the holographic image), providing an intuitive and effective comparative analysis method. In particular, by varying the LCoS resolution ratio, the change in the resolvable minimum pixels of the holographic image is interpreted in conjunction with the average speckle size; moreover, an analysis of the correlation between the latter two is presented. This approach, based on LCoS resolution division, could provide useful insights into single-SLM-based, full-color holographic displays using space division. Furthermore, it could be extended to other components, including more advanced LCoS SLMs, and used to identify the relative effects on image quality with speckles.     

Irreversible capacity of the amorphous silicon thin-film electrodes

Irreversible processes accompanying the lithium incorporation into amorphous thin-film silicon are investigated. It is shown that the irreversible processes occurred during the cathodic polarization result in the formation of passive film at the silicon surface. The passive film at silicon is close, in its composition, to the passive film at carbonaceous materials. However, unlike the carbonaceous electrodes, no effect of electrolyte composition on the irreversible capacity of the silicon electrodes is observed.     

普鲁士蓝修饰电极结合硅溶胶-凝胶技术制备高灵敏葡萄糖传感器

基于普鲁士蓝修饰玻碳电极结合二氧化硅溶胶 凝胶固定化酶技术构造具有“三明治”式结构的酶电极。考察了酶电极对葡萄糖的电化学响应以及操作条件。结果表明 :所制备的传感器在pH 6 .5 ,电位为- 0 .0 5V条件下对葡萄糖在 0～ 5mmol/L呈线性响应 ,响应时间为 12s ,检出限为 0 .0 2mmol/L ,灵敏度高达1 182 μA/ (mmol·L-1)。传感器的稳定性好 ,4 5d其响应值仍保持 90 %。     

Adsorption of triethygermane on Si(100): thermal and nonthermal channels for ethyl ligand removal/dissociation

Adsorption of triethylgemane (TEG) on the Si(100) surface at 100 K has been studied using a variety of surface‐sensitive spectroscopies. Thermally and electronically desorbed species were analyzed using temperature‐programmed desorption (TPD) and electron‐stimulated desorption (ESD) techniques. Electronically desorbed ions (H⁺) were analyzed using a time‐of‐flight technique (TOF) and time evolution studies were conducted on desorbing neutral species. Direct analysis of surface species were carried out using X‐ray photoelectron spectroscopy (XPS) and high‐resolution electron energy loss (HREELS) spectroscopy. Evidence is offered for (1) an electron‐induced channel for direct ethylene desorption via a β‐hydride elimination process; (2) an electron‐stimulated transfer of ethyl ligands from a Ge to a Si site; and (3) both thermal‐ and electron‐stimulated desorption of methyl groups. Copyright © 2006 John Wiley & Sons, Ltd.     

铜在ρ-Si上激光诱导电沉积过程的研究

由于在微电子器件制造，成像系统及太阳能电池等领域里具有广阔的应用前景，激光诱导化学及电化学沉积金属的研究，最近几年引起了极大兴趣［1－3］，例如Zahavi［4］报道了Pd，Au，Ni－Pd在氩离子激光作用下可以不加偏压实现在半导体Si，InPGaAs上的无掩膜选择性沉积，金属沉积只发生在光照部位．大多数研究工作是围绕应用技术而开展的，理论研究，尤其是光电化学方面的研究尚十分欠缺．我们认为对于普通电镀液中的激光诱导电沉积来讲，既使不需外加偏压，沉积过程也必然伴随着溶液中金属离子与半导体能带之间的电荷传递，因此可以通…     

聚碳硅烷纤维的空气不熔化处理

用热重和红外光谱分析了聚碳硅烷纤维在空气中的不熔化处理过程, 确定了不熔化处理的反应机理和反应条件。通过控制不熔化处理程度, 有效地改善了碳化硅纤维的力学性能。     

Atmosphere effects in the processing of silicon carbide and silicon oxycarbide thin films and coatings

Silicon carbide and silicon oxycarbide films were prepared from solutions of polycarbosilane and methyldimethoxysilane + tetraethoxysilane, respectively, and deposited on different substrates (Si wafers, stainless steel plates, sapphire and SiC fibers). The coatings were heated at different temperatures and in different atmospheres, such as regular grade argon, ultra high purity and argon vacuum. The films were characterized using different techniques (FT-IR, XRD, SIMS, Ellipsometry).The influence of the processing parameters (heat treatment temperature and atmosphere) on the final microstructure of the coatings is discussed in this article.     

Synthesis and catalytic properties of tetraorganodistannoxanes containing silicon

Three tetraorganodistannoxanes containing silicon were synthesized and their catalytic properties in esterification and acetalization were observed via the reactions of acetic acid with isoamyl alcohol and butyraldehyde with glycol. The factors affecting the reaction, such as the catalyst dosage, reaction time and solvent, etc. were discussed. The results show that the three tetraorganodistannoxanes displayed similar good catalytic activities compared to dichlorotetrabutyldistannoxane in esterification and acetalization. When the dosage of [ClBu₂SnOSn-(CH₂SiMe₃)₂Cl]₂ was 1.5% based on the mass of reactant, the yield of isoamyl acetate was 91.8% and the yield of butyraldehyde glycol acetal 94.2%. The different alkyl and bridging groups on Sn sites in the structure of tetraorganodistannoxanes showed some influence on the catalytic activities of these compounds. __________ Translated from Chinese Journal of Applied Chemistry, 2007, 24 (11): 1265–1272