Investigations on PbS/SiPY-Based Photocathode for Photoelectrochemical Reduction of CO2

Abstract

Lead Sulfide (PbS) nanoparticle-decorated silicon (Si) pyramids array on Si-based photocathodes are fabricated by using pure chemical methods. The PbS thin layers were synthesized by chemical solution deposition onto flat Silicon (Si) and pyramidal textured Silicon (SiPY) obtained from alkaline Si substrate etching. Scanning Electron Microscopy (SEM) was used to carry out the morphological characterization, while UV–Vis-NIR Spectroscopy was used to study the optical properties. The Linear sweep voltammetry (LSV) was conducted to study the catalytic activity in dark and under white light irradiation using a potentiostat station. Cyclic voltammetry in the presence of and without purging CO₂ was also investigated. The LSV investigations showed the synergy effect between PbS thin films and Si for the rising and transport of the charge carriers. The results showed a higher photocatalytic towards CO₂ reduction of PbS/SiPY compared to Silicon substrate without surface texturization and sensitization. The photoelectrode based on PbS/SiPY could efficiently be used as a photocathode for the photoelectrochemical (PEC) reduction of CO₂ to Methanol.