In-Situ Growth of NiFe2O4/2D MoS2 p-n Heterojunction Immobilizing Palladium Nanoparticles for Enhanced Visible-Light Photocatalytic Activities

Solar energy is considered as a green and abundant energy for catalytic reactions. In this work, a magnetically recoverable NiFe2O4/2D MoS2-Pd nanocomposite is successfully synthesized via a simple one-pot hydro thermal method. The intimate interfacial contact between NiFe2O4 nanocubes and corrugated MoS2 nanosheets forms the NiFe2O4/2D MoS2 p-n heterojunction, while plasmonic Pd nanoparticles are uniformly immobilized on the surface of it. Dye degradation and Suzuki-Miyaura coupling reaction are employed to evaluate the photocatalytic activity of the NiFe2O4/2D MoS2 Pd nanocomposite. Significantly, both dye degradation and Suzuki-Miyaura coupling reaction can be efficiently performed in a short time under mild conditions. In comparison, the physically mixed NiFe2O4+2D MoS2 heterojunction immobilizing palladium nanoparticles shows poor photocatalytic activity. Photocatalytic results demonstrate that the in situ formation of NiFe2O4/2D MoS2 p-n heterojunction greatly improves the visible-light absorption and facilitates the transferring of photogenerated electrons and holes. Moreover, Pd nanoparticles as the electron reservoirs can further suppress the electron hole recombination and enhance the photocatalytic activity. The construction of semiconductive p-n heterojunction to immobilize metal nanocatalysts will be an inspiration for other useful photocatalytic applications.