LAUSR

Abstract We adopt the dip-coating method using the viscosity of TiO2 sol to carry out the experiment aiming at combining both the advantage of morphologies of ordered and disordered nanostructures to select the photo-anode of TiO2. The nanoparticles scattering layer thin film growing at the TiO2 nanotubes (H:TTW) nozzle (H:TTWP) can increase the specific surface area of the top structure as well as can improve the adsorption of the quantum dots. Meanwhile, this nanostructure can keep the advantage of the direct electronic channel and the less vertical structure interface at the bottom of nanotubes. We use the method of successive ionic layer adsorption and reaction (SILAR) to conduct the quantum dot co-sensitization on the H:TTWP with CdS and Bi2S3. We found that the number of dip-coating with TiO2 nanoparticles was 6, it exhibited the best performance and reached a high photocurrent density of 9.34 mA/cm2, which is 2.1-times as many as Bi2S3/CdS/H:TTW system. What's more, the photoconversion efficiency is 6.13%. The improvement of the performance is mainly due to the enhancement of light absorption and the amount of heterojunctions of Bi2S3/CdS/TiO2, the ladder-like energy level structure and the novel morphology structure.