Room Temperature Dissolution of Bulk Elemental Ni and Se for Solution Deposition of a NiSe2 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 NiSe2 as an efficient hydrogen evolution reaction (HER) catalyst. Thin films of phase-pure NiSe2 are deposited from a precursor ink prepared by room-temperature dissolution of bulk elemental Ni and Se in a binary thiolamine solvent mixture. The nanostructured NiSe2 thin films demonstrate high HER catalytic activity with 100% Faradaic efficiency.