BSA-caged metal clusters to exfoliate MoS2 nanosheets towards their hybridized functionalization

Abstract

Herein, we develop a facile exfoliation and in situ functionalization strategy to produce hybridized Au/MoS₂ nanostructures comprised of size-controlled gold nanoparticles (Au NPs) and ultrathin MoS₂ nanosheets by using bovine serum albumin (BSA)-caged Au₂₅ clusters as both exfoliating and functionalizing agents. As revealed, BSA molecules are strongly adsorbed on MoS₂via their hydrophobic interaction, and this drives the expansion of the BSA molecules that initially protect Au₂₅ cores at pH 4, leading to the effective exfoliation of MoS₂ nanosheets together with the epitaxial growth of Au₂₅ cores into 5 nm-sized Au NPs on MoS₂ nanosheets due to their reduced surface protection. Upon the addition of H₂O₂, the resulting Au NPs can further grow to achieve a controlled size from 5 to 30 nm with an increase of the reaction time. It is demonstrated that the hybridized Au/MoS₂ nanosheets exhibit a better performance in the photocatalytic degradation of substrates compared to the individual components or their mixture. Moreover, the hybridized Ag/MoS₂, Au/WO₃ and Au/graphene nanosheets are further produced by the usage of BSA-caged Ag and Au clusters, respectively. Overall, this work reports the first utilization of protein-caged metal clusters for the exfoliation and hybridized functionalization of 2D materials, and this brings more opportunities to exploit unusual properties of hybridized 2D materials for novel applications.