Preparation of electrocatalysts using a thiol-amine solution processing method.

Solution processing has emerged as a promising option for the preparation of functional materials with methods that tend to be cheap, less energy intensive, and allow for high throughput and large area deposition. A recently developed method, whereby a binary thiol-amine solvent mixture is used to dissolve bulk oxides, chalcogenides, or elemental materials to yield molecular precursor inks for the deposition of phase pure chalcogenide materials, has recently garnered attention for applications in optoelectronics, thermoelectrics, and electrocatalysis. Presented here is a summary of reports on the application of this "alkahest" method for the deposition of electrocatalytic materials.

Room Temperature Dissolution of Bulk Elemental Ni and Se for Solution Deposition of a NiSe HER Electrocatalyst.

With hydrogen fuel becoming a more viable alternative to fossil fuels comes the need for inexpensive, low-energy hydrogen production. Here, a low-temperature direct solution-processing method is presented for the deposition of earth-abundant pyrite-type NiSe as an efficient hydrogen evolution reaction (HER) catalyst. Thin films of phase-pure NiSe are deposited from a precursor ink prepared by room-temperature dissolution of bulk elemental Ni and Se in a binary thiolamine solvent mixture.

Solution processing of chalcogenide materials using thiol-amine "alkahest" solvent systems.

Macroelectronics is a major focus in electronics research and is driven by large area applications such as flat panel displays and thin film solar cells. Innovations for these technologies, such as flexible substrates and mass production, will require efficient and affordable semiconductor processing. Low-temperature solution processing offers mild deposition methods, inexpensive processing equipment, and the possibility of high-throughput processing.

Dissolution of Sn, SnO, and SnS in a Thiol-Amine Solvent Mixture: Insights into the Identity of the Molecular Solutes for Solution-Processed SnS.

Binary solvent mixtures of alkanethiols and 1,2-ethylenediamine have the ability to readily dissolve metals, metal chalcogenides, and metal oxides under ambient conditions to enable the facile solution processing of semiconductor inks; however, there is little information regarding the chemical identity of the resulting solutes. Herein, we examine the molecular solute formed after dissolution of Sn, SnO, and SnS in a binary solvent mixture comprised of 1,2-ethanedithiol (EDT) and 1,2-ethylenediamine (en). Using a combination of solution (119)Sn NMR and Raman spectroscopies, bis(1,2-ethanedithiolate)tin(II) was identified as the likely molecular solute present after the dissolution of Sn, SnO, and SnS in EDT-en, despite the different bulk material compositions and oxidation states (Sn(0) and Sn(2+)).

Solution-Phase Conversion of Bulk Metal Oxides to Metal Chalcogenides Using a Simple Thiol-Amine Solvent Mixture.

A thiol-amine solvent mixture is used to dissolve ten inexpensive bulk oxides (Cu2O, ZnO, GeO2, As2O3, Ag2O, CdO, SnO, Sb2O3, PbO, and Bi2O3) under ambient conditions. Dissolved oxides can be converted to the corresponding sulfides using the thiol as the sulfur source, while selenides and tellurides can be accessed upon mixing with a stoichiometric amount of dissolved selenium or tellurium. The practicality of this method is illustrated by solution depositing Sb2Se3 thin films from compound inks of dissolved Sb2O3 and selenium that give high photoelectrochemical current response.