Platinum Nanoparticle Co-Catalyst-Induced Improved Photoelectrical Properties in a Chromium-Doped SrTiO3 Photocatalyst

Abstract

SrTi1-xCrxO3 (0 <= x <= 0.5) photocatalysts were prepared by using conventional solid state reactions at 1300 degrees C for 5 h and were characterized by using ultraviolet-visible (UV-vis) absorption spectroscopy. SrTi1-xCrxO3 samples not only absorb UV light photons, but also visible light photons due to substitutional doping of chromium at titanium sites in the SrTiO3 lattice. Apparently, the band transition from the Cr 3d to the Cr 3d + Ti-3d hybrid orbital induces visible light absorptivity in SrTi1-xCrxO3 samples. The photocatalytic activity of Cr-doped SrTiO3 samples for hydrogen production from water-methanol mixtures tinder UV light irradiation decreased with increased Cr doping concentration in SrTiO3. Conclusively, there exists an optimum chromium and platinum concentration in SrTiO3 for achieving high photocatalytic activity under visible light (lambda >= 420 nm)