Synthesis of a Ternary Thiostannate with 3D Channel Decorated by Hydronium for High Proton Conductivity

Water assisted high proton conductance in a pure-inorganic framework vanadoborate

A pure-inorganic framework vanadoborate is successfully synthesized under hydrothermal conditions and exhibits good proton conductivity.

Abundant defects of zirconium-organic xerogels: High anhydrous proton conductivities over a wide temperature range and formic acid impedance sensing

There exists a challenge to develop solid-state proton conductors with high conductivity not only at high working temperatures (>353 K) but at start-up temperature and even at subzero temperature (<273 K) in cold climates or high-altitude drones. Here we present a series of zirconium-organic xerogels (Zr/Fum-xerogels) with porosity and defectivity, supported by N₂ sorption, thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS), exhibiting a high anhydrous proton conductivity over the temperature range of 233 to 433 K. The anhydrous conductivity of Zr/Fum-xerogel-0.04 reaches 5.68 × 10^-4 (233 K) and 2.5 × 10^-2 S cm^-1 (433 K), situating in the leading level of all anhydrous conductors reported to date. Further, the defective effects on acidities and conductive mechanisms of xerogels, especially structural changes of water clusters generated by varying temperatures are investigated by ion exchange capacity (IEC), X-ray photoelectron spectroscopy (XPS), temperature programmed desorption of NH₃ (NH₃-TPD) and in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The zirconium-organic xerogels with outstanding conducting performance is further implemented as impedance sensor towards formic acid.

One-Dimensional Vanadium(III) Chalcogenidostannates Incorporating [V(tepa)]3+ Complexes as Bridging Groups

Two new one-dimensional (1D) vanadium(III) chalcogenidostannates, [H₂tepa]_0.5n[V^III(tepa)(μ-Sn₂Q₆)]_n [Q = S (1), Se (2); tepa = tetraethylenepentamine], were achieved by solvothermal methods, which offer the first examples of organic hybrid polymeric chalcogenidostannates incorporating [V(tepa)]³⁺ complexes as bridging groups. Both 1 and 2 feature the 1D sinusoidal chains of [V^III(tepa)(μ-Sn₂Q₆)]_n containing two types of novel bridging modes of the [μ-Sn₂Q₆]^4- anion. Their magnetic, photocurrent response, and optical properties are also studied.

Proton Conduction of an Acid-Resistant Open-Framework Chalcogenidometalate Hybrid in Anhydrous versus Humid Environments

Solid proton conductors are broadly applicable to various electrochemical devices; therefore, it is highly desirable to develop robust materials with high proton conductivity under both anhydrous and humid environments within a wide temperature range. In this work, we investigated the proton conducting properties of a 3D open-framework chalcogenidometalate hybrid, [CH₃NH₃]₂[H₃O]Ag₅Sn₄Se₁₂·C₂H₅OH (1), which exhibited both anhydrous and water-assisted proton conduction. Importantly, the excellent thermal and chemical stabilities of hybrid 1 are superior to many MOF-based proton conducting materials. This present study proved to be a considerable advance based on open-framework chalcogenidometalates in the design of robust solid proton conducting materials that are capable of operating under humid and anhydrous environments in a wide temperature range.

Open-Framework Chalcogenide Showing Both Intrinsic Anhydrous and Water-Assisted High Proton Conductivity

Proton-conducting materials have attracted increasing interest because of the promising technological applications as key components in various electrochemical devices. It is of great significance for technique application to seek superior proton-conducting materials, operating under both anhydrous and humidified conditions in a wide temperature range. Herein we demonstrate the proton conductance of an open-framework chalcogenide, (CH₃NH₃)₂Ag₄Sn₃S₈ (1), and the postsynthesis product 2 achieved by doping hydrochloric acid into 1. Hybrid 2 displays both intrinsic anhydrous and water-assisted high proton conductance, with σ = 1.87 × 10^-4 S·cm^-1 at 463 K under N₂ atmosphere and 1.14 × 10^-3 S·cm^-1 at 340 K and 99% relative humidity, and these conductivities are comparable to that in the efficient metal-organic frameworks-based proton-conducting materials. Moreover, hybrid 2 shows excellent thermal stability and long-term stability of proton conduction.