Nano titanium dioxide coating Haematococcus pluvialis enhances photoelectric carbon dioxide reduction performance

In this study, we utilized a hydrothermal method to coat TiO2 nanoparticles onto Haematococcus pluvialis (H. pluvialis) cells. Various methods were employed to investigate the morphology, structure, and photoelectrocatalytic activity of the synthesized Ys/TiO2 composites. Results indicated that, owing to the dye-sensitization effect of astaxanthin within H. pluvialis cells, the electron-hole pairs in Ys/TiO2 composites achieved efficient charge separation, leading to superior photoelectrocatalytic CO2 reduction performance. The composites also exhibited a broader wavelength absorption range with a Faradaic efficiency of up to 61.28%, and a liquid product yield of ethanol reaching 29.47 μmol·h−1·cm−2. Furthermore, the H. pluvialis/TiO2 composites maintained high photoelectrocatalytic activity and stability even after four cycles.