Fundamentals of Electrochemistry

Fundamentals of Electrochemistry build on basic oxidation-reduction reactions and present an overview of their use in electrochemical cells. The construction and operation of a galvanic cell is described with cell diagrams including the function of the electrodes (cathode and anode). Also covered are the standard electrode potential and its applications, including calculations involving the standard electrode potential, the Gibbs free energy and the equilibrium constant, determination of the spontaneity in redox reactions and the dependence of cell potential on concentration (the Nernst equation). Finally a qualitative and quantitative overview of electrolysis is presented with a focus on predicting the products of electrolysis and the stoichiometry of electrolysis, which relates the charge flowing through an electrolytic cell to the amount of products formed at the electrodes.

A Rechargeable Na/Cl Battery

Sodium is a promising anode material for batteries due to its low standard electrode potential, high abundance and low cost. In this work, we report a new rechargeable ~ 3.5 V sodium ion battery using Na anode, amorphous carbon-nanosphere cathode and a starting electrolyte comprised of AlCl3 in SOCl2 with fluoride-based additives. The battery, exhibiting ultrahigh ~ 2800 mAh/g first discharge capacity, could cycle with a high reversible capacity up to ~ 1000 mAh/g. Through battery cycling, the electrolyte evolved to contain NaCl, various sulfur and chlorine species that supported anode’s Na/Na+ redox and cathode’s chloride/chlorine redox. Fluoride-rich additives were important in forming a solid-electrolyte interface, affording reversibility of the Na anode for a new class of high capacity secondary Na battery.

Impact of Heavy Oil Sewage Components on the Performance of Coagulated Particles

In this paper, the relationship between the components of heavy oil wastewater and thesurface wettability of coagulation particles were studied. The effects of cations (Ca2+, Mg2+, Fe2+,Fe3+), oil content and pH on wettability of coagulated particles surface in heavy oil wastewater werestudied by measuring the contact Angle, and the possible mechanism was discussed. It was foundthat the contact Angle decreased with the increase of pH value. The change of oil content isnegatively correlated with the contact Angle. Surface wettability of coagulated particles arecorrelated with cationic concentration in sewage and standard electrode potential. When cationicconcentration is less than 500 mg/L, surface wettability is positively correlated with standardelectrode potential. When cationic concentration is more than 1000 mg/L, surface wettability ismainly related to the total amount of cationic ions in sewage.

High-Yield Synthesis of Long Silver Nanowires via Chromic Chloride and a Stable Reaction Environment

The search for suitable synthesis methods and parameters capable of controlling the length, diameter, and yield of silver nanowires (AgNWs) is still an emerging strategy today. Therefore, a method for high-yield synthesis of long AgNWs via chromic chloride and a stable reaction environment was proposed. The results show that Cr3+ could restore the adsorbed atomic oxygen quickly and provide a high efficiency in the prevention of the oxidative etching, for the ion of Cr2+ oxidized to Cr3+ has a lower standard electrode potential, and a more stable reaction environment provided by the coupling method could avoid disturbing the growth of the {111} reactive sites of the wires; then, the yield and length of the AgNWs were improved. The length of the AgNWs was over 75 μm and even 160 μm; the yield of the AgNWs was over 90%, which provides the referable basis for the synthesis of ultralong AgNWs.