TiO2 nanoparticles anchoring on two-dimensional Bi2Se3 nanosheet as an enhanced visible light catalyst

Titanium dioxide (TiO 2 ) has been widely studied in the field of photocatalysis. However, the development of TiO 2 was limited by the photoresponse only in the ultraviolet region and the rapid recombination of photogenerated electron–hole pairs. In this work, we prepare a novel TiO 2 and two-dimensional (2D) bismuth selenide (Bi 2 Se 3 ) hybrid nanosheets (TiO 2 /Bi 2 Se 3 HNs) via a simple water bath ultrasonic route. X-ray diffraction pattern and Raman spectra were carried out to confirm that as-prepared samples were pure and well crystalized. Besides, TEM characterization proves that 2D Bi 2 Se 3 nanosheets have high specific surface area and it can be clearly observed that the TiO 2 with 60 nm particles are uniformly supported on the surface. Furthermore, photoelectrochemical (PEC) measurements demonstrate that the TiO 2 /Bi 2 Se 3 HNs exhibit excellent photocatalytic performance of 4.3 µA/cm 2 under 100 W of visible light, which were almost 2.5 times that of pure TiO 2 . More importantly, our results show that 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 Bi 2 Se 3 nanosheets, such as maximized reaction sites and good electrical conductivity, and the positive coupling effect of the TiO 2 /Bi 2 Se 3 heterojunction. These extraordinary properties make the TiO 2 /Bi 2 Se 3 HNs photocatalysts have excellent potential for photocatalytic application.