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Molecular dynamics (MD) simulations have become a powerful tool for investigating electrical double layers (EDLs), which play a crucial role in various electrochemical devices. In this Review, we provide a comprehensive overview of the techniques used in MD simulations for EDL studies, with a particular focus on methods for describing electrode polarization, and examine the principle behind these methods and their varying applicability. The applications of these approaches in supercapacitors, capacitive deionization, batteries, and electric double-layer transistors are explored, highlighting recent advancements and insights in each field. Finally, we emphasize the challenges and potential directions for future developments in MD simulations of EDLs, such as considering movable electrodes, improving electrode property representation, incorporating chemical reactions, and enhancing computational efficiency to deepen our understanding of complex electrochemical processes and contribute to the progress in the field involving EDLs. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) water splitting is one of the most important approaches being investigated for solar fuel generation. In this study, we determine the maximum thermodynamic power conversion efficiencies (PCEs) of PEC water splitting two-bandgap tandem devices that produce multiple carriers per photon absorbed via Multiple Exciton Generation (MEG) or Singlet Fission (SF) and in the presence of solar concentration. Here, we employ a detailed balance thermodynamic analysis to determine the effects of top cell thickness, solar concentration, carrier multiplication, electrode overvoltage (VO), and water absorption on PEC power conversion efficiency for water splitting cells. We have found a maximum PEC power conversion efficiency of 62.9% in cells using two ideal tandem MEG absorbers with bandgaps of 0.3 and 1.2 eV at 1000-suns solar concentration and 0 overvoltage; the maximum PCE for two tandem SF absorbers under the same conditions is nearly the same at 59% with the same values for the absorption thresholds. A very interesting and important result was that, upon thinning the top cell, the range of viable bandgaps for both the top and bottom cells is extended by as much as 0.5–1 eV while still maintaining high maximum conversion efficiency (60–63%). The effects of imposing different solar concentrations from 1X to 1000X and having different tandem configurations of SF and MEG layers were also studied. [ABSTRACT FROM AUTHOR]

Transport of liquid mixtures through porous membranes is central to processes such as desalination, chemical separations, and energy harvesting, with ultrathin membranes made from novel 2D nanomaterials showing exceptional promise. Here, we derive, for the first time, general equations for the solution and solute fluxes through a circular pore in an ultrathin planar membrane induced by a solute concentration gradient. We show that the equations accurately capture the fluid fluxes measured in finite-element numerical simulations for weak solute–membrane interactions. We also derive scaling laws for these fluxes as a function of the pore size and the strength and range of solute–membrane interactions. These scaling relationships differ markedly from those for concentration-gradient-driven flow through a long cylindrical pore or for flow induced by a pressure gradient or an electric field through a pore in an ultrathin membrane. These results have broad implications for transport of liquid mixtures through membranes with thickness on the order of the characteristic pore size. [ABSTRACT FROM AUTHOR]