Metal-doped molybdenum nitride films for enhanced hydrogen evolution in near-neutral strongly buffered aerobic media

A series of molybdenum nitride films, viz., Mo3N2, Ag-Mo3N2, V-Mo3N2 and Cu-Mo3N2 have been fabricated by magnetron co-sputtering technique and evaluated as HER electrocatalysts in near-neutral pH (pH 5) buffer medium. An optimal HER activity has been observed at about 1.8 M phosphate buffer with Cu-Mo3N2 showing highest activity. Under strongly buffered and oxygen saturated conditions the molybdenum nitride films have consistently shown very high HER selectivity in the presence of oxygen. The stability of the molybdenum nitride films has been enhanced retaining almost 100% of the initial activity in a durability test, whereas, a significant loss in the stability has been observed for the same catalysts in 0.5 M H2SO4 solution. (C) 2018 Elsevier Ltd. All rights reserved.