Synthesis of Titanium Dioxide/Cadmium Sulfide Nanosphere Particles for Photocatalyst Applications

Semiconductor nanocomposites, which are composed of titanium dioxide (TiO2) nanorods, cadmium sulphide (CdS) nanoparticles (NPs), and Ni clusters, were synthesized. The following steps were adopted: (i) surfactant-capped TiO2 nanorods with controlled length were synthesized in an autoclave using oleic acid and amino hexanoic acid as surfactants. By using a ligand-exchange procedure, in which nitrosonium tetrafluoroborate (NOBF4) was used to replace the original surfactants, hydrophilic NOBF4-TiO2 nanorods were obtained; (ii) the resulting nanorods were deposited with CdS NPs and (iii) then deposited selectively with Ni clusters (as cocatalyst) on the nanocomposite surface. Under visible-light illumination of the nanocomposite, the generated electrons from the conduction band of CdS are transferred to TiO2 via TiO2/CdS interface, then to metallic Ni cluster. As a result, the electron hole separation was highly enhanced, leading to a Ni-TiO2/CdS nanocomposite with high photocatalytic performance for the production of hydrogen (H-2).