The research, published in the journal Solar RRL, focuses on anatase TiO2, a material known for its chemical stability and photocatalytic capabilities, but limited by its wide bandgap that restricts its activity to the ultraviolet spectrum. To overcome this bottleneck, the strategic integration of TiO2 with TMDs like MoS2 has been explored. This combination harnesses interfacial charge transfer dynamics, Schottky barrier formation, and bandgap renormalization to extend light absorption into the visible range while suppressing charge carrier recombination.
The study performs a systematic ab initio investigation of the anatase TiO2 (001) surface interfaced with MoS2. The aim is to elucidate how distinct surface terminations govern structural relaxation, interfacial bonding, and the electronic properties of the TiO2/MoS2 Van der Waals heterostructure. It compares the ideal bulk-terminated (1 × 1) surface with the experimentally stable reconstructed (1 × 4)-ADM surface, highlighting their key similarities and differences and clarifying the atomistic origins of the resulting behavior.
The findings indicate that both systems maintain a type-II alignment, reducing the bandgap relative to bulk TiO2 with a redshifted absorption. The unreconstructed (1 × 1) surface is found to be ideal for MoS2 interfacing, optimally meeting Z-scheme requirements.
This research, led by scientists at ICMAB-CSIC and published under the title "Surface Termination Unlocks Photocatalytic Potential: Reshaping Structure and Electronics in Ultrathin MoS2/TiO2 Heterojunctions", opens new avenues for designing more efficient photocatalytic materials for clean energy applications.
