TiO2-Pd/C composited photocatalyst with improved photocatalytic activity for photoreduction of CO2 into CH4

摘要

A novel Pd-modified TiO2 photocatalyst composited with carbon nanoparticles (TiO2-Pd/C) was synthesized via a sol-gel method. Characterized by XRD, Raman, BET, HRTEM, EDAX, XPS, absorption spectra and PL techniques, the introduced Pd existed as unique O-Pd-O species, and C existed as the substance carbon nanoparticles on the surface of TiO2, behaving as a composited photocatalyst on a nanoscale. Based on the experimental results and theoretical calculations, it was found that the introduction of O-Pd-O surface species and the carbon nanoparticles extend the absorption into the visible light region and facilitate the separation of photogenerated charge carriers, resulting in a much better photocatalytic activity of the photo-reduction of CO2 into CH4, than would be achieved with TiO2-Pd and TiO2/C samples.