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.