Innovative preparation of MoS2–graphene heterostructures based on alginate containing (NH4)2MoS4 and their photocatalytic activity for H2 generation

Films and particles of MoS₂ on graphene (G) showing synergy for photocatalytic H₂ evolution due to the strong interaction between the two layered components have been obtained by pyrolysis at 900 °C under argon flow of ammonium alginate, films or powders, containing variable proportions of (NH₄)₂MoS₄. X-ray diffraction shows that under these conditions (NH₄)₂MoS₄ decomposes to MoS₂, while simultaneously alginate forms few layers G or graphitic carbon residues. Sonication of MoS₂–G powders in water produces exfoliation of the material leading to few-layers platelets of MoS₂–G heterostructures. MoS₂ is considered as an alternative of noble metals for H₂ evolution in dye-sensitized photocatalytic systems. In the present case, MoS₂–G heterostructures exhibit more than double photocatalytic activity for H₂ generation than pristine MoS₂ particles.