FeS2 bridging function to enhance charge transfer between MoS2 and g–C3N4 for efficient hydrogen evolution reaction

Abstract

High–performance composite electrocatalysts of g–C 3 N 4 /FeS 2 /MoS 2 for hydrogen evolution reaction (HER) is synthesized by the growth of molybdenum disulfide (MoS 2 ) nanosheets from ferrous disulfide (FeS 2 ) sites supported on graphite–like carbon nitride (g–C 3 N 4 ) substrates. The high conductivity of such composite catalysts is induced by the Fe S bond between FeS 2 and MoS 2 and Fe N bond between FeS 2 and g–C 3 N 4 . These two bonds of Fe S and Fe N can have a bridging function to provide efficient charge transfer channels between g–C 3 N 4 and MoS 2 via chemical bonding rather than physical attachment. Furthermore, the FeS 2 sites can prevent the agglomeration of MoS 2 nanosheets and also seed the MoS 2 to form highly dispersed vertical growth nanosheets with more exposed edging active sites. As a result, this g–C 3 N 4 /FeS 2 /MoS 2 catalyst exhibits both high catalytic HER activity and stability. FeS 2 acting as bridge to deliver electrons from g–C 3 N 4 to the active sites of MoS 2 to accelerate the hydrogen production reaction. • FeS 2 decorated on g-C 3 N 4 achieves homogeneous distribution of MoS 2 nanosheets. • Vertical growth of MoS 2 nanosheets induced by FeS 2 seeds benefits the HER process. • The Fe N bonds between FeS 2 and g-C 3 N 4 provide fast charge transfer channels. • The tailored catalyst exhibits high electrocatalytic activity toward HER.