Efficient hydrogen production over Bi2Te3-modified TiO2 catalysts: A first principles study

First-principles calculations based on the HSE06 exchange-correlation functional were employed to investigate the electronic properties of the TiO2 heterostructure modified with Bi2Te3 co-catalyst. The objective was to gain a deeper understanding of the role of this material in overall photocatalytic hydrogen evolution reaction (HER). We meticulously examined the combined effects of Bi2Te3 and TiO2 on electronic properties, charge transfer and visible light response. Density of states analysis revealed that the Bi2Te3/TiO2 interface structure introduces optimal band offsets, which facilitates the migration of photo-generated electrons in heterostructure, effectively suppressing electron-hole recombination. Furthermore, the Dirac cone characteristics of Bi2Te3 reduced the effective mass of the photo-generated electrons, promoting rapid electron-hole separation and thereby enhancing the utilization efficiency of photo-generated carriers. Additionally, compared to standalone TiO2 films, the Te atoms in Bi2Te3 within the heterostructure introduce extra catalytic active sites, further boosting its photocatalytic HER efficiency. This research not only deepens our understanding of the photocatalytic HER process in the Bi2Te3/TiO2 heterostructure but also provides a robust theoretical foundation for the design of Bi2Te3-based co-catalysts.