Growth of MoS2 Nanoflakes and the Photoelectric Response Properties of MoS2/TiO2 NRs Compositions

The initial reactant concentration and the substrate play an important role on the nucleation and growth of MoS 2 nanostructures during hydrothermal growth. In this work, MoS 2 nanoflakes are grown on FTO and TiO 2 nanorod arrays (NRs) substrates. The morphology, optical and photoelectric properties of MoS 2 nanoflakes are affected by the initial reactant concentration. Compared with the FTO substrate, MoS 2 nanoflakes tend to grow on TiO 2 NRs substrates due to less mismatch between TiO 2 and MoS 2 . The large surface roughness and the presence of surface states of the TiO 2 NRs facilitate the nucleation and growth of MoS 2 nanoflakes. The photoelectric characteristics of MoS 2 /TiO 2 NRs compositions have been investigated. The MoS 2 /TiO 2 NRs compositions prepared using the initial reactant concentration with 4 mM S atom concentration exhibit the higher photoresponse behavior, which is attributed to the better heterojunction contact interface between MoS 2 nanoflakes and TiO 2 NRs. MoS 2 nanoflakes can not completely cover the TiO 2 NRs under low initial reactant concentration, resulting in the small area of the contact interface. On the other hand, MoS 2 nanoflakes tend to form the self-assembly nanoflowers under high initial reactant concentration, which induces the carriers recombination in MoS 2 , the poor transport properties of MoS 2 and the detrimental effects on the photogenerated current.