Efficient charge transfer on the tunable morphology of TiO/MoS photocatalyst for an enhanced hydrogen production

The TiO 2 /MoS 2 heterostructure consisting of varying concentrations of layered MoS 2 on TiO 2 of different morphology was fabricated successfully by a simple hydrothermal method. In this work, we employed TiO 2 with different morphologies (commercial, nanotube, hierarchical, and nanosheets) for the synthesis of TiO 2 /MoS 2 to examine the effect of morphology on hydrogen evolution trend. In particular, the photoinjected electron lifetime was greatly influenced by the structural pattern of the photocatalyst, as photoluminescence spectroscopy study revealed superior electron transfer efficiency in TiO 2 nanosheets of the composite. The structure and optical properties of the as-prepared TiO 2 /MoS 2 hybrid materials were confirmed by XRD, SEM, TEM, and PL studies. The hybrid materials indicated the heterostructure formation in the fine-tuned MoS 2 -TiO 2 composite. The resultant TiO 2 /MoS 2 showed good photocatalytic response than the pristine TiO 2 and MoS 2 . Furthermore, at optimized MoS 2 to TiO 2 ratio in the composite, a series of photocatalysts were screened, such as TiO 2 (commercial)/MoS 2 , TiO 2 (nanotube)/MoS 2 , TiO 2 (hierarchical)/MoS 2 and TiO 2 (nanosheets)/MoS 2 with 2 wt% content of MoS 2 , and 29.71, 41.33, 65.54 and 77.41 μmol h −1 g −1 of hydrogen evolution was found, respectively. TiO 2 (nanosheet)/MoS 2 showed the highest rate of hydrogen evolution activity among them, and the introduction of MoS 2 to TiO 2 decreased the rate of charge carrier recombination and increased the hydrogen evolution activity. While promising, these approaches consisting of novelty that includes low cost, simple synthesis process, chemically robust and effective charge transfer pathways have shown to be effective for solar energy conversion to the clean fuel hydrogen production. In this study, carefully controlled 2D MoS 2 /TiO 2 heterostructure serves as an excellent photocatalytic agent for the solar energy conversion to chemical fuels.