A situ hydrothermal synthesis of a two-dimensional MoS2/TiO2 heterostructure composite with exposed (001) facets and its visible-light photocatalytic activity

Abstract

Two-dimensional (2D) MoS2/TiO2 heterostructure composites with exposed (001) facets (MT-001) were fabricated through a situ hydrothermal method. The microstructure and composition of the composite material were characterized by XRD, TEM, and XPS. TEM results showed that the composite consisted of well-defined sheet-shaped structures with a rectangular outline and a length of approximately 80–140 nm. XPS results demonstrated that the MoS2 coated on the surface of TiO2 nanosheets with (001) facets (T-001). Further investigation of UV–Vis diffuse reflectance spectra revealed that light absorption had the strongest visible light range after T-001 compounded with MoS2. The photocatalytic activity of the composites were estimated by the photocatalytic degradation of methylene blue (MB) under visible light irradiation. Compared with T-001, The MT-001 exhibited better photocatalytic activity in MB degradation because of the formation of nano-heterojunction, which originated from intimate interfacial contacts as well as the suitably matching conduction and valance levels between MoS2 and T-001. When the MoS2 loading contents of MT-001 reached 5 wt% (5 wt% MT-001), the corresponding MB degradation rate was 83.26% under visible-light irradiation for 30 min; this value is approximately 1.44 times that of T-001. The possible visible-light photocatalytic mechanism was also proposed.