A thermodynamic model for calculating the mass action concentrations of structural units in Fe-Si binary melts based on the atom-molecule coexistence theory, i.e., the AMCT-N i model, has been developed and verified through comparing with the reported activities of both Si and Fe in the full composition range of Fe-Si binary melts at temperatures of 1693, 1773, 1873, and 1973

Knowledge of atomistic structures at solid/liquid interfaces is essential to elucidate interfacial processes in chemistry, physics, and materials sciences. The (Ö3´Ö7) structure associated with a pair of sharp reversible current spikes in the cyclic voltammogram on a Au(111) electrode in sulfuric acid solution, represents one of the most classical structures at electrode/electrolyte interfaces. Although more than ten adsorption configurations have been proposed by more than ten groups in the past four decades, the atomistic structure remains ambiguous and is consequently an open problem in electrochemistry and surface science. Herein, by combining high-resolution electrochemical scanning tuning microscopy, electrochemical infrared and Raman spectroscopies, and in particular, the newly developed quantitative computational method for electrochemical infrared and Raman spectra, we unambiguously reveal that the adstructure is Au(111)(Ö3´Ö7)-(SO4•••w2) with a sulfate anion (SO4*) and two structured-water molecules (w2*) in a unit cell, and the crisscrossed [w•••SO4•••w]n and [w•••w•••]n hydrogen-bonding network comprises the symmetric adstructure. We further elucidate that the electrostatic potential energy dictates the proton affinity of sulfate anions, leading to the potential-tuned structural transformations. Our work enlightens the structural details of the inner Helmholtz plane and thus advances our fundamental understanding of the processes at electrochemical interfaces.

The electro-oxidation of p-aminothiophenol (PATP) on gold electrodes has been investigated by means of density functional theory. A combination of thermodynamic calculations and surface Raman and infrared (IR) spectral simulations has allowed us to reveal the electro-oxidation mechanism and reaction products of PATP on gold electrodes in acidic, neutral, and basic solutions. PATP can be first oxidized to the radical cation PATP(NH2 •+) or the neutral radical PATP(NH•) depending on the pH of aqueous solutions, and this is the rate-determining step. The radical cation or neutral radical can then transform to the dimerized products through a radical coupling reaction. In the acidic medium, the radical cation reacts with its resonance hybrid through a N–C4 coupling to form 4′-mercapto-N-phenyl-1,4-quinone diimine (D1), which can further undergo hydrolysis to yield 4′-mercapto-N-phenyl-1,4-quinone monoimine (D2). In the neutral medium, the neutral radical reacts with its resonance hybrid through the N–C2(6) coupling to form 4,4′-dimercapto-N-phenyl-1,2-quinone diimine (D3). In the basic medium, the neutral radical reacts with its resonance structure through the N–N coupling to form 4,4′-di­mercapto­azo­benzene (D4). The adsorbed dimer products exhibit reversible redox properties. The calculated standard electrode potentials of the above four species decrease in the order D3, D1, D2, and D4. Finally, the characteristic bands for the surface Raman and IR spectra of D1 to D4 redox pairs are clearly assigned. This study provides mechanistic insight into the electrochemical reaction properties of PATP on metal electrodes.

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As the most advanced energy storage devices, lithium ion batteries (LIBs) have captured a great deal of attention and have been developed swiftly during the past decades. However, the improved fast-charging performance is more urgent than ever for time-saving and convenience, which is generally limited by the graphite anode. Recent studies have revealed that the fast-charging performance of graphite anodes is highly dictated by the properties of the electrolyte. Therefore, the investigations on fast-charging graphite based on designs of electrolytes are summarized from two aspects: solid electrolyte interphase (SEI) structures and solvated lithium ion structures. Finally, challenges and prospects for further research toward fast-charging graphite anodes are proposed.

CuO feather-like and flower-like crystals have been synthesized by a fast microwave-assisted solution approach using Cu(NO 3 ) 2 and NaOH. The morphology transformation of CuO could be achieved by ionic liquid 1-n-butyl-3-methyl imidazolium tetrafluoroborate ([BMIM]BF 4 ). With [BMIM]BF 4 , flower-like CuO were obtained, whereas without [BMIM]BF 4 , featherlike CuO were obtained. The possible formation mechanism of flower-like CuO was discussed on the basis of experimental results. The products were characterized by XRD, FESEM/EDS, and TEM/SAED. In addition, the adsorption of [BMIM]BF 4 on flower-like CuO was confirmed by FTIR and TG/DSC, and the band gap energies of the flower-like CuO was estimated by UV-vis spectra.

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The Raoultian activity coefficient γSi0 of Si and γFe0 of Fe in the infinitely dilute solution of FeSi binary melts at temperatures of 1693, 1773, 1873, and 1973 K have been determined from the calculated mass action concentrations Ni of structural units in FeSi binary melts based on the atom and molecule coexistence theory (AMCT). The activity coefficients of elements γi relative to pure liquid matter as standard state or f%, i referred to 1 mass percentage as standard state or fH, i based on the hypothetical pure liquid matter as standard state have been obtained. The values of first‐order activity interaction coefficient ϵii or eii or hii of Si and Fe related with activity coefficients γi or f%, i or fH, i of Si and Fe are also determined. The standard molar Gibbs free energy change of dissolving liquid element i(l) for forming 1 mass percentage of element i in FeSi binary melts have been deduced in a temperature range from 1693 K to 1973 K. The molar mixing thermodynamic properties, such as molar mixing Gibbs energy change/enthalpy change/entropy change of FeSi binary melts have been reliably determined in a temperature range from 1693 K to 1973 K. The excess values and excess degrees of the above–mentioned molar mixing thermodynamic properties of FeSi binary melts have been also determined based on ideal solution or regular solution as a basis, respectively. The determined molar mixing Gibbs energy change of FeSi binary melts is equal to that based on regular solution as a basis in the full composition range of FeSi binary melts in a temperature range from 1693 K to 1973 K. The partial mixing thermodynamic properties of Si and Fe are not recommended to obtain from the calculated mass action concentration NSi of Si and NFe of Fe as well as the measured activity aR, Si of Si and aR, Fe of Fe in FeSi binary melts.