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

High–performance composite electrocatalysts of g–C3N4/FeS2/MoS2 for hydrogen evolution reaction (HER) is synthesized by the growth of molybdenum disulfide (MoS2) nanosheets from ferrous disulfide (FeS2) sites supported on graphite–like carbon nitride (g–C3N4) substrates. The high conductivity of such composite catalysts is induced by the FeS bond between FeS2 and MoS2 and FeN bond between FeS2 and g–C3N4. These two bonds of FeS and FeN can have a bridging function to provide efficient charge transfer channels between g–C3N4 and MoS2 via chemical bonding rather than physical attachment. Furthermore, the FeS2 sites can prevent the agglomeration of MoS2 nanosheets and also seed the MoS2 to form highly dispersed vertical growth nanosheets with more exposed edging active sites. As a result, this g–C3N4/FeS2/MoS2 catalyst exhibits both high catalytic HER activity and stability.