Fabrication of Z-Scheme TiO2/SnS2/MoS2 ternary heterojunction arrays for enhanced photocatalytic and photoelectrochemical performance under visible light

In the current work, Z-scheme TiO2/SnS2/MoS2 ternary heterojunction arrays were synthesised on a fluorine-doped tin oxide conductive glass by using a facile hydrothermal technique. The microstructures, energy band structures, and photocatalytic performances of TiO2, TiO2/SnS2, and TiO2/MoS2 were investigated. The results revealed that for methylene blue, ternary TiO2/SnS2/MoS2 exhibited considerably enhanced photocatalytic efficiency (similar to 79%) and the optimal transient current density (similar to 0.92 mA/cm(2)) under visible-light irradiation; these two values were four and eight times higher than those exhibited by TiO2, respectively. The highly improved photocatalytic and photoelectrochemical performance could be attributed to the unique microstructure and band alignment of TiO2/SnS2/MoS2. These attributes can be explained as follows: (i) the large specific surface area offers numerous active sites, (ii) the modulation of the narrow-band SnS2 and MoS2 broadens visible-light response, and (iii) the Z-scheme heterojunction effectively restricts the bulk recombination and spatially separates the photogenerated electron-hole (e(-)-h(+)) pairs.

Automated summary

Z-scheme TiO2/SnS2/MoS2 ternary heterojunction arrays synthesized by a hydrothermal technique exhibit enhanced photocatalytic and photoelectrochemical performance due to their unique microstructure and band alignment.