Synthesis of titania wrapped cadmium sulfide nanorods for photocatalytic hydrogen generation

Herein we report a simplified synthetic approach for a semiconductor photocatalyst (CdS) wrapped with a nanoscale thin-layer of semiconducting material (TiO2) to overcome the instability issues, besides the improved catalytic efficiency. Images of HR-TEM and elemental mapping evidenced the presence of CdS that covered by ultra thin-layer of TiO2 as shell. The UV-vis diffuse reflectance spectra showed red-shift in absorption edge in visible region. The photocatalytic water splitting towards hydrogen production using Na2S/Na2SO4 as sacrificial agent was evaluated under UV-vis and visible light irradiation. The essential variables such as thickness of TiO2 shell, amount of sacrificial agent and solution pH were fine tuned to achieve hydrogen generation of 5791 mL h(-1) g(-1) of catalyst. The higher efficiency is ascribed to core/shell morphology of CdS/TiO2 system that channelled the excitons to the surface for the red-ox reactions rather than recombination. The catalytic stability result ascertained that the photo-corrosion is greatly suppressed.