Sulfidation and selenidation of nickel nanoparticles

NPs using elemental sulfur,1-hexadecanthiol,thiourea,trioctylphosphine sulfide,elemental selenium,and selenourea.While maintaining mole ratios of 2 mmol sulfur/selenium precursor:mmol Ni,products with phases of Ni_(3)S_(2),Ni_(9)S_(8),NiS,NiSO_(4)·6H_(2)O,Ni_(3)S_(4),Ni_(3)Se_(2),and NiSe have been obtained.The products have voids that form through the Kirkendall effect during interdiffusion.Trends relating the chemical properties of the precursors to the phases of the products have been identified.While some precursors contained phosphorus,there was no significant incorporation of phosphorus in any of the products.An increase of the NP size during sulfidation and selenidation is consistent with ripening.The application of Ni sulfide and selenide NPs as electrocatalysts for the hydrogen evolution reaction is also demonstrated.