Silver nanoparticles as co-catalysts of Ta₂O₅ nanotubes in hydrogen photogeneration

Full text: In the challenger for renewable energy sources highlighting water splitting process by means of solar energy. In this context, nanotubes of tantalum pentoxide are used in this process as catalysts, however, they absorb radiation only in the ultraviolet region of the electromagnetic spectrum. In order to improve the efficiency silver nanoparticles were used as co-catalysts since they absorb radiation in the visible region of the spectrum. The nanotubular structures were synthesized by the anodizing process. The synthesis of the NP_Ag, as well as the sensitization of the nanotubes, were carried out by the chemical reduction process having as precursor a solution of AgNO₃. The nanocomposites were characterized by Electron Transmission Electron Microscopy (MET); Diffuse Reflectance Spectroscopy (DRS) and X-Ray Diffraction (XRD). The photogeneration of H₂ was carried out in a solar simulator for 8h and 450 μl aliquots of the Headspace were collected from the reactor every 30 minutes and analyzed in the gaseous chromatographic (GC). The synergism of noble metals with semiconductor photocatalysts brings significant changes to photocatalysis[1] and in this sense, the results show that NP_Ag as a co-catalyst increased the efficiency of nanotubes by 90% more than the matrix that was not decorated. This value corresponds to 1246 μmol/g gas produced. Reference: [1] Zielinska-Jurek, A. Progress, Challenge, and Perspective of Bimetallic TiO2- Based Photocatalysts. Journal of Nanomaterials, 2014.