Modelling and Fixed Bed Column Adsorption of Cr(Ⅵ) onto Orthophosphoric Acid-activated Lignin

The advantage of using an available and abundant residual biomass, such as lignin, as a raw material for activated carbons is that it provides additional economical interest to the technical studies. In the current investigation, a more complete understanding of adsorption of Cr（VI） from aqueous systems onto HaPO4-acid activated lignin has been achieved via microcolumns, which were operated under various process conditions. The practice of using microcolumn is appropriate for defining the adsorption parameters and for screening a large number of poten- tial adsorbents. The effects of solution pH （2-8）, initial metal ion concentration （0.483-1.981 mmol.L-1）, flow rate （1.0-3.1 cm3-min-1）, ionic strength （0.01-0.30 mmol-L-1） and adsorbent mass （0.11 0.465 g） on Cr（VI） adsorption were studied by assessing the microcolmnn breakthrough curve. The microcolumn data were fitted by the Thomas model, the modified Dose model and the BDST model. As expected, the adsorption capacity increased with initial Cr（VI） concentration. High linear flow rates, pH values and ionic strength led to early breakthrough of Cr（VI）. The model constants obtained in this study can be used for the design of pilot scale adsorption process.

Metal-assisted chemical etching of silicon and the behavior of nanoscale silicon materials as Li-ion battery anodes

This review outlines the developments and recent progress in metal-assisted chemical etching of silicon, summarizing a variety of fundamental and innovative processes and etching methods that form a wide range of nanoscale silicon structures. The use of silicon as an anode for Li-ion batteries is also reviewed, where factors such as film thickness, doping, alloying, and their response to reversible lithiation processes are summarized and discussed with respect to battery cell performance. Recent advances in improving the performance of silicon-based anodes in Li-ion batteries are also discussed. The use of a variety of nanostructured silicon structures formed by many different methods as Li-ion battery anodes is outlined, focusing in particular on the influence of mass loading, core-shell structure, conductive additives, and other parameters. The influence of porosity, dopant type, and doping level on the electrochemical response and cell performance of the silicon anodes are detailed based on recent findings. Perspectives on the future of silicon and related materials, and their compositional and structural modifications for energy storage via several electrochemical mechanisms, are also provided.

Durable Super-repellent Surfaces: From Solid−Liquid Interaction to Applications

CONSPECTUS:A super-repellent surface is a type of liquid-repellency material that allows for various liquid drops to bead up,roll off,or even bounce back.Known for its ability to remain dry,perform self-cleaning,and have a low adhesion,a super-repellent surface presents great advantages in a number of applications.These include antifogging,anti-icing,oil/water separation,and fluid drag reduction.To fend off the liquids or drops,super-repellent surfaces combine the merits of surface chemistry and physical structure.By taking advantage of a low surface energy to prevent liquid from spreading,the super-repellent surfaces utilize the micronano structure to provide a framework that confines the solid−liquid interactions.Compared to beading up the drop of water,the repellence of liquid with low surface tension requires the subtle design of surface structure to resist the wetting of liquids.However,the inherent instabilities of the fragile micronano structure of super-repellent surfaces and solid−liquid interactions further make the fabrication of super-repellent surfaces complex to withstand dynamic environments(friction or wear)during application.In addition,the transparency and thermal stability of super-repellent surfaces are also the restrictive factors in some special application scenarios.To solve these challenges,durable super-repellent surfaces that can repel various liquids,possess robust mechanical and thermal stability,and show high transparency have been explored extensively in recent years.

Fabrication of Noble metal-semiconductor hybrid nanostructures using phase transfer

An easy and effective solution based procedure for the synthesis of noble metal （both Au and Ag） tipped semiconductor nanomaterials is demonstrated where the metal precursors are taken in water and the semiconductors in organic medium, exploiting the phase transfer and reducing capability of suitably chosen ligands. The phase tranfer route is a generalised approach to form either Ag or Au tips on cadmium chalcogenide nanoparticles and nanorods. While multiple dots of noble metals are formed on the semiconductor nanomaterials initiall~ these coalesce into larger islands with time. The hybrids are characterized by transmission electron microscopy （TEM）, X-ray diffraction （XRD）, photoluminescence （PL）, ultraviolet-visible spectroscopy （UV-vis） and X-ray photoelectron spectroscopy （XPS）. A detailed FTIR analysis was also carried out to delineate the role of the ligands in the synthesis.