The sonochemical functionalization of MoS2 by zinc phthalocyanine and its visible light-induced photocatalytic activity

Abstract

Here, the synthesis of a molybdenum disulfide–zinc phthalocyanine (MoS₂–ZnTTBPc) composite is reported where the scalable synthesis of MoS₂ was done by a simple solvothermal route followed by the sonochemical attachment of ZnTTBPc. The as-synthesized material acquires a monolayer with an average thickness of 2 nm. Raman studies give sufficient evidence of the existence of monolayer MoS₂ in the MoS₂–ZnTTBPc composite. The highly exfoliated plentiful active sites available on the 2D surface of MoS₂ efficiently act as photocatalytic reaction centers. Moreover, the high energy transfer efficiency, authenticated by steady-state photoluminescence and time-correlated single photon counting studies, makes the MoS₂–ZnTTBPc (3 : 1) composite a promising optoelectronic and photocatalytic material. The photogenerated electrons from the conduction band of ZnTTBPc transfer to the conduction band of MoS₂ leaving holes at the valence band of ZnTTBPc, and simultaneously the photogenerated holes from the valence band of MoS₂ transfer to the valence band of ZnTTBPc. These well-separated charges reduce the electron–hole recombination probability in the composite, subsequently offering a positive synergetic effect among ZnTTBPc and single-layered MoS₂ sheets. It could thus have promise as a new photocatalyst towards removing different organic pollutants and for other optoelectronic devices.