A Hydrogen Evolution Reaction (HER) catalyst includes at least one component selected from a group consisting of transition metal phosphides and first row transition metal sulfides. The catalyst can be included in nanoparticles. In some instances, the catalyst is included in a hydrogen evolution reaction electrode. In one example, the catalyst is cobalt phosphide.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
 This invention was made with government support under grant numbers CHE1305124 and CHE0802907 awarded by the National Science Foundation and grant number DE-SC0004993 awarded by the Department of Energy. The government has certain rights in the invention.