Electron Transport Mediated by Peptides Immobilized on Surfaces

Abstract

The tetragonal compound FeF3(H2O)3 is synthesized through a facile liquid‐phase method. FeF3(H2O)3/C is prepared by mechanical milling with carbon black and investigated for its application as a cathode material. This material exhibits two types of thermodynamic lithiation scheme, at 3.0 and 1.5 V, which correspond to a Li+‐intercalation process (1 Li+) and a conversion reaction (>1 Li+), respectively. A reversible capacity of about 300 mAh g−1 can be achieved at a current density of 10 mAg−1. In particular, the intercalation/deintercalation process above 2.0 V exhibits good cycling performance and rate properties. The relatively high diffusion coefficients (Dcv=7.27×10−13–1.07×10−12 m2 s−1) of Li+ through the FeF3(H2O)3 lattice are calculated by using the Randles–Sevcik equation, which reveal fast Li+‐ion migration in this process. In contrast, the conversion reaction is strongly dependent on the current density. Electrochemical impedance spectroscopy indicates that the FeF3(H2O)3/C cathode forms a relatively stable solid electrolyte interphase film, with a low Schottky contact resistance in comparison with that of the FeF3/C cathode, which makes it a potential candidate for cathode applications.

Dipole Moment Effect on the Electrochemical Desorption of Self‐Assembled Monolayers of 310‐Helicogenic Peptides on Gold

“…The dipole moment of molecular species plays different roles of fundamental and applied significance. For example, different ET (or electron‐transport) rates have been found for opposite orientations of the peptides in SAMs; similar effects were observed for ET in freely diffusing donor–peptide–acceptor systems . Thermodynamics, however, could also be responsible for making ET rates different: as a matter of fact, we already showed that an oriented peptide dipole moment affects significantly the redox potentials of electroactive groups and gold clusters .…”

A controllable mechanistic transition of charge transfer in helical peptides: from hopping to superexchange

“…Here the free energy difference (DG) ij is approximated by the energy gap (DE) ij . The overall electron transfer rate constant for a two-step sequential hopping pathway was then calculated using a previously reported kinetic model, 10 that assumes steady-state occupation probability for different diabatic states (see eqn (4) and (5)). The outer-sphere reorganization energy (l) outer,ij from the diabatic state (i)to the neighboring diabatic state (j) is given by 45…”

“…4 However, one must rst understand and subsequently be able to predict and control the associated charge transfer mechanisms. 5 Two main modes, superexchange (tunnelling) and thermally activated hopping, are widely accepted. 6 The superexchange mechanism of electron transfer involves direct molecule-mediated tunnelling, where the intervening peptide chain between electron donor and acceptor takes on a virtual role.…”

Thermoelectric properties of oligoglycine molecular wires

“…Understanding electron transport through biomolecules is important, because they play central roles in cellular respiration, photosynthesis and enzymatic reactions. [1][2][3][4][5][6][7] Although much effort has been devoted to transport in peptides, 8,9 the exact mechanism of charge transport through peptides and proteins is still under debate. Generally, it is accepted that quantum tunnelling through molecular orbitals is the dominant mechanism for short peptide chains 10,11 and consequently their electrical conductance G decays exponentially with length as G = Ae −βl , 12,13 where the prefactor A is a constant reflecting the molecule-electrode coupling strength, l is the separation between two electrodes and β is an attenuation constant.…”