Photoelectrochemical conversion of CO2 using nanostructured PbS-Si Photocathode

A n-type nanostructured PbS thin films were prepared by chemical bath deposition onto flat Silicon (Si) and Silicon nanowires (SiNWs) which were derived from electroless etching of Si substrates. The morphological characterization was carried out by scanning electron microscopy (SEM), while the optical properties were studied using Ultraviolet-Visible Spectroscopy (UV-Vis). The catalytic activity was studied by linear sweap voltammetry (LSV) in dark and under white light irradiation using potentiostat station. Cyclic voltammetry in presence and without purging CO2 was also conducted. The LSV investigations showed the coupling effect between PbS thin films and Si for the rising and transport of the charge carriers. The results showed a higher photocatalytic activity toward CO2 reduction of PbS/SiNWs compared to Silicon substrate without any surface modification and sensitization. The electrode based on PbS/SiNWs/Si could efficiently be used as photocathode for the PEC reduction of CO2 to Methanol. [GRAPHICS] .