Photocatalytic hydrogen production on chemically etched strontium titanate surfaces

This work aims to investigate the photocatalytic hydrogen evolution over acid (citric acid and hydrochloric acid) etched strontium titanate (SrTiO3), which is promoted by 1 wt% platinum (Pt) as co-catalyst. Scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible spectroscopy (UV-Vis) analyses of the un-etched and etched SrTiO(3)are presented; the results indicate that etching affects the surface structure while it does not change the bulk properties of semiconductor. The results of the photocatalytic activity tests performed in a methanol solution using a semi-batch reaction system equipped with argon flow to collect hydrogen, 300 W xenon lamp as light source and gas chromatograph for the analysis, are also reported. The etching with 4 mol L(-1)citric acid increases the hydrogen evolution rate about 20% while the highest rate of hydrogen production over etched Pt-SrTiO(3)is about 550 mu mol/gcat.h at the 6 h of the reaction test.