TiO2 Nanoparticles Anchoring on Two-Dimensional Bi2Se3 Nanosheet As An Enhanced Visible Light Catalyst

Abstract Titanium dioxide (TiO2) has been widely studied in the field of photocatalysis. However, the development of TiO2 was limited by the photoresponse only in the ultraviolet region and the rapid recombination of photogenerated electron-hole pairs. In this work, TiO2 and two-dimensional (2D) bismuth selenide (Bi2Se3) hybrid nanosheets (TiO2/Bi2Se3 HNs) have been prepared via a simple ultrasonic route. X-ray diffraction pattern and Raman spectra were carried out to confirm that as-prepared samples were pure and well crystalized. Besides, the microstructure characterization proves that 2D Bi2Se3 nanosheets have high specific surface area and can serve as a stable platform to construct the intimate interaction with TiO2. Furthermore, photoelectrochemical (PEC) measurements demonstrate that the TiO2/Bi2Se3 HNs exhibit excellent photocatalytic performance under visible light, which were much better than pure TiO2 and Bi2Se3. More importantly, the photocurrent density was quite stable and only dropped by 10% after 125 cycles. In summary, the improved photocatalytic activity is due to the unique characteristic of 2D Bi2Se3 nanosheets, such as maximized reaction sites and good electrical conductivity, and the positive coupling effect of the TiO2/Bi2Se3 heterojunction. This study indicates that TiO2/Bi2Se3 HNs photocatalysts have excellent potential for photocatalytic application.