An Approach to an Ideal Molecule-Based Mixed Conductor with Comparable Proton and Electron Conductivity

Abstract

We synthesized a molecule-based proton–electron mixed conductor (PEMC), a Pt­(III) dithiolate complex with 1,4-naphthoquinone skeletons. The π-planar Pt complex involves a π-stacking column, which is connected by one-dimensional hydrogen bonding chains composed of water molecules. The room-temperature (RT) proton conductivity is 8.0 × 10–5 S cm–1 under ambient conditions, which is >2 orders of magnitude higher than that of the isomorphous Ni complex (7.2 × 10–7 S cm–1). The smaller activation energy (0.23 eV) compared to that of the Ni complex (0.42 eV) possibly originates from the less dense water, which promotes the reorientational dynamics, in the Pt complex with an expanded lattice, namely, negative chemical pressure upon substitution of Ni with the larger Pt. In addition, the Pt complex shows a relatively high RT electronic conductivity of 1.0 × 10–3 S cm–1 caused by the π-columns, approaching an ideal PEMC with comparable proton and electron conduction.

Rational Construction of Molecular Electron-Conducting Nanowires Encapsulated in a Proton-Conducting Matrix in a Charge Transfer Salt

“…Thereafter, we evaluated the proton conductivity of (TTF) 2 ( 1-H 6+δ ) using the pelletized sample sandwiched with Nafion membranes as the electron blocking electrode ,, (refer to Figure S9 for the result of the experiment on only Nafion films). The Nyquist plots obtained from ac impedance measurements at different temperatures (25–45 °C; Figure a) under 40% RH were well fitted by assuming the combination of sample intrinsic (proton) conductivity and sample/electrode interface.…”

Data-Driven High-Throughput Screening and Experimental Realization of Ag2B(IV)B′(VI)O6 under Negative Chemical-Pressure

“…Ion-exchange reaction allows for the incorporation of cations from a molten salt into a material without altering the structural framework. By varying the types of precursors and molten salts, it is possible to simulate NP and synthesize hidden metastable materials. − (3) Solid solution trapping. Modification under lattice mismatch between the host and guest can cause a volumetric expansion reference to the guest content to accommodate the NP phase. , …”