pH-dependence on HER electrocatalytic activity of iron sulfide pyrite nanoparticles

Abstract Iron sulfide pyrite (FeS 2 ) nanoparticles are investigated for the electrocatalysis of hydrogen evolution reaction (HER) at pH values ranging from 0.3 to 13. It is evidenced that HER can be performed at any pH, showing remarkable robustness and stability for more than 24 h. The catalytic mechanism for HER by pyrite nanoparticles changes over the pH range, with a pH-dependent behavior below pH 5 and a pH-independent behavior above pH 5.